在KitKat之前（或新图库之前），Intent.ACTION_GET_CONTENT返回了这样的URI
content://media/external/images/media/3951。
使用ContentResolver并查询 MediaStore.Images.Media.DATA返回了文件 URL。
然而，在 KitKat 中，图库返回一个 URI（通过"最后"），如下所示：
content://com.android.providers.media.documents/document/image:3951
我该如何处理？
这不需要特殊权限，并且适用于存储访问框架以及非官方ContentProvider模式（_data字段中的文件路径）。
/**
* Get a file path from a Uri. This will get the the path for Storage Access
* Framework Documents, as well as the _data field for the MediaStore and
* other file-based ContentProviders.
*
* @param context The context.
* @param uri The Uri to query.
* @author paulburke
*/
public static String getPath(final Context context, final Uri uri) {
final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;
// DocumentProvider
if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {
// ExternalStorageProvider
if (isExternalStorageDocument(uri)) {
final String docId = DocumentsContract.getDocumentId(uri);
final String[] split = docId.split(":");
final String type = split[0];
if ("primary".equalsIgnoreCase(type)) {
return Environment.getExternalStorageDirectory() + "/" + split[1];
}
// TODO handle non-primary volumes
}
// DownloadsProvider
else if (isDownloadsDocument(uri)) {
final String id = DocumentsContract.getDocumentId(uri);
final Uri contentUri = ContentUris.withAppendedId(
Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));
return getDataColumn(context, contentUri, null, null);
}
// MediaProvider
else if (isMediaDocument(uri)) {
final String docId = DocumentsContract.getDocumentId(uri);
final String[] split = docId.split(":");
final String type = split[0];
Uri contentUri = null;
if ("image".equals(type)) {
contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
} else if ("video".equals(type)) {
contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
} else if ("audio".equals(type)) {
contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
}
final String selection = "_id=?";
final String[] selectionArgs = new String[] {
split[1]
};
return getDataColumn(context, contentUri, selection, selectionArgs);
}
}
// MediaStore (and general)
else if ("content".equalsIgnoreCase(uri.getScheme())) {
// Return the remote address
if (isGooglePhotosUri(uri))
return uri.getLastPathSegment();
return getDataColumn(context, uri, null, null);
}
// File
else if ("file".equalsIgnoreCase(uri.getScheme())) {
return uri.getPath();
}
return null;
}
/**
* Get the value of the data column for this Uri. This is useful for
* MediaStore Uris, and other file-based ContentProviders.
*
* @param context The context.
* @param uri The Uri to query.
* @param selection (Optional) Filter used in the query.
* @param selectionArgs (Optional) Selection arguments used in the query.
* @return The value of the _data column, which is typically a file path.
*/
public static String getDataColumn(Context context, Uri uri, String selection,
String[] selectionArgs) {
Cursor cursor = null;
final String column = "_data";
final String[] projection = {
column
};
try {
cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs,
null);
if (cursor != null && cursor.moveToFirst()) {
final int index = cursor.getColumnIndexOrThrow(column);
return cursor.getString(index);
}
} finally {
if (cursor != null)
cursor.close();
}
return null;
}
/**
* @param uri The Uri to check.
* @return Whether the Uri authority is ExternalStorageProvider.
*/
public static boolean isExternalStorageDocument(Uri uri) {
return "com.android.externalstorage.documents".equals(uri.getAuthority());
}
/**
* @param uri The Uri to check.
* @return Whether the Uri authority is DownloadsProvider.
*/
public static boolean isDownloadsDocument(Uri uri) {
return "com.android.providers.downloads.documents".equals(uri.getAuthority());
}
/**
* @param uri The Uri to check.
* @return Whether the Uri authority is MediaProvider.
*/
public static boolean isMediaDocument(Uri uri) {
return "com.android.providers.media.documents".equals(uri.getAuthority());
}
/**
* @param uri The Uri to check.
* @return Whether the Uri authority is Google Photos.
*/
public static boolean isGooglePhotosUri(Uri uri) {
return "com.google.android.apps.photos.content".equals(uri.getAuthority());
}
在此处查看此方法的最新版本。
试试这个：
if (Build.VERSION.SDK_INT <19){
Intent intent = new Intent();
intent.setType("image/jpeg");
intent.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(Intent.createChooser(intent, getResources().getString(R.string.select_picture)),GALLERY_INTENT_CALLED);
} else {
Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT);
intent.addCategory(Intent.CATEGORY_OPENABLE);
intent.setType("image/jpeg");
startActivityForResult(intent, GALLERY_KITKAT_INTENT_CALLED);
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode != Activity.RESULT_OK) return;
if (null == data) return;
Uri originalUri = null;
if (requestCode == GALLERY_INTENT_CALLED) {
originalUri = data.getData();
} else if (requestCode == GALLERY_KITKAT_INTENT_CALLED) {
originalUri = data.getData();
final int takeFlags = data.getFlags()
& (Intent.FLAG_GRANT_READ_URI_PERMISSION
| Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
// Check for the freshest data.
getContentResolver().takePersistableUriPermission(originalUri, takeFlags);
}
loadSomeStreamAsynkTask(originalUri);
}
可能需要
@SuppressLint（"NewApi"）
为
takePersistableUriPermission
遇到同样的问题，尝试了上面的解决方案，但尽管它通常有效，但由于某种原因，尽管我正确添加了android.permission.MANAGE_DOCUMENTS权限，但我对某些图像的 Uri 内容提供商的权限被拒绝。
无论如何，找到了其他解决方案，即强制打开图像库而不是KITKAT文档视图：
// KITKAT
i = new Intent(Intent.ACTION_PICK,android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(i, CHOOSE_IMAGE_REQUEST);
，然后加载图像：
Uri selectedImageURI = data.getData();
input = c.getContentResolver().openInputStream(selectedImageURI);
BitmapFactory.decodeStream(input , null, opts);
编辑
ACTION_OPEN_DOCUMENT可能需要您保留权限标志等，并且通常会导致安全异常...
另一种解决方案是将ACTION_GET_CONTENT与c.getContentResolver().openInputStream(selectedImageURI)结合使用，这将适用于 pre-KK 和 KK。Kitkat 将使用新的文档视图，此解决方案将适用于所有应用程序，如照片、图库、文件资源管理器、保管箱、谷歌云端硬盘等......但请记住，使用此解决方案时，您必须在onActivityResult()中创建映像并将其存储在SD卡上。下次应用启动时从保存的 uri 重新创建此图像会在内容解析器上引发安全异常，即使您按照 Google API 文档中的说明添加权限标志也是如此（这就是我进行一些测试时发生的情况）
此外，Android 开发者 API 指南建议：
ACTION_OPEN_DOCUMENT 并非旨在替代ACTION_GET_CONTENT。您应该使用的一个取决于以下需要您的应用：
如果您希望应用仅读取/导入，请使用ACTION_GET_CONTENT数据。使用此方法，应用会导入数据的副本，例如图像文件。
如果您希望应用具有 ACTION_OPEN_DOCUMENT对文档拥有的文档的长期持久访问供应商。例如，允许用户编辑的照片编辑应用程序存储在文档提供程序中的图像。
正如Commonsware提到的，你不应该假设你通过ContentResolver获得的流是可以转换为文件的。
您真正应该做的是从ContentProvider打开InputStream，然后从中创建位图。它也适用于 4.4 及更早版本，无需反思。
//cxt -> current context
InputStream input;
Bitmap bmp;
try {
input = cxt.getContentResolver().openInputStream(fileUri);
bmp = BitmapFactory.decodeStream(input);
} catch (FileNotFoundException e1) {
}
当然，如果你处理大图像，你应该用适当的inSampleSize：http://developer.android.com/training/displaying-bitmaps/load-bitmap.html 加载它们。但这是另一个话题。
我相信
已经发布的回复应该让人们朝着正确的方向前进。但是，这是我所做的，对我正在更新的旧代码有意义。旧代码使用库中的 URI 来更改图像，然后保存图像。
在 4.4（和谷歌云端硬盘）之前，URI 如下所示：content://media/external/images/media/41
如问题中所述，它们通常如下所示：content://com.android.providers.media.documents/document/image:3951
由于我需要能够保存图像并且不会干扰现有代码，因此我只是将 URI 从图库复制到应用程序的数据文件夹中。然后从数据文件夹中保存的图像文件生成一个新的 URI。
这个想法是这样的：
Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setType("image/*");
startActivityForResult(intent), CHOOSE_IMAGE_REQUEST);
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
File tempFile = new File(this.getFilesDir().getAbsolutePath(), "temp_image");
//Copy URI contents into temporary file.
try {
tempFile.createNewFile();
copyAndClose(this.getContentResolver().openInputStream(data.getData()),new FileOutputStream(tempFile));
}
catch (IOException e) {
//Log Error
}
//Now fetch the new URI
Uri newUri = Uri.fromFile(tempFile);
/* Use new URI object just like you used to */
}
注意 - copyAndClose（） 只是执行文件 I/O 以将 InputStream 复制到 FileOutputStream 中。代码未发布。
只是想说这个答案很棒，我用了很长时间没有问题。但是前段时间我偶然发现了一个问题，即 DownloadsProvider 以 content://com.android.providers.downloads.documents/document/raw%3A%2Fstorage%2Femulated%2F0%2FDownload%2Fdoc.pdf 格式返回 URI，因此应用程序因NumberFormatException而崩溃，因为无法解析其 uri 段那么长。但是raw:段包含可用于检索引用文件的直接 URI。因此，我通过将isDownloadsDocument(uri) if内容替换为以下内容来修复它：
final String id = DocumentsContract.getDocumentId(uri);
if (!TextUtils.isEmpty(id)) {
if (id.startsWith("raw:")) {
return id.replaceFirst("raw:", "");
}
try {
final Uri contentUri = ContentUris.withAppendedId(
Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));
return getDataColumn(context, contentUri, null, null);
} catch (NumberFormatException e) {
Log.e("FileUtils", "Downloads provider returned unexpected uri " + uri.toString(), e);
return null;
}
}
我将多个答案组合成一个工作解决方案，结果为文件路径
MIME 类型与示例目的无关。
Intent intent;
if(Build.VERSION.SDK_INT >= 19){
intent = new Intent(Intent.ACTION_OPEN_DOCUMENT);
intent.putExtra(Intent.EXTRA_ALLOW_MULTIPLE, false);
intent.addFlags(Intent.FLAG_GRANT_PERSISTABLE_URI_PERMISSION);
}else{
intent = new Intent(Intent.ACTION_GET_CONTENT);
}
intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
intent.setType("application/octet-stream");
if(isAdded()){
startActivityForResult(intent, RESULT_CODE);
}
处理结果
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
if( requestCode == RESULT_CODE && resultCode == Activity.RESULT_OK) {
Uri uri = data.getData();
if (uri != null && !uri.toString().isEmpty()) {
if(Build.VERSION.SDK_INT >= 19){
final int takeFlags = data.getFlags() & Intent.FLAG_GRANT_READ_URI_PERMISSION;
//noinspection ResourceType
getActivity().getContentResolver()
.takePersistableUriPermission(uri, takeFlags);
}
String filePath = FilePickUtils.getSmartFilePath(getActivity(), uri);
// do what you need with it...
}
}
}
FilePickUtils
import android.annotation.SuppressLint;
import android.content.ContentUris;
import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.os.Build;
import android.os.Environment;
import android.provider.DocumentsContract;
import android.provider.MediaStore;
public class FilePickUtils {
private static String getPathDeprecated(Context ctx, Uri uri) {
if( uri == null ) {
return null;
}
String[] projection = { MediaStore.Images.Media.DATA };
Cursor cursor = ctx.getContentResolver().query(uri, projection, null, null, null);
if( cursor != null ){
int column_index = cursor
.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
cursor.moveToFirst();
return cursor.getString(column_index);
}
return uri.getPath();
}
public static String getSmartFilePath(Context ctx, Uri uri){
if (Build.VERSION.SDK_INT < 19) {
return getPathDeprecated(ctx, uri);
}
return FilePickUtils.getPath(ctx, uri);
}
@SuppressLint("NewApi")
public static String getPath(final Context context, final Uri uri) {
final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;
// DocumentProvider
if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {
// ExternalStorageProvider
if (isExternalStorageDocument(uri)) {
final String docId = DocumentsContract.getDocumentId(uri);
final String[] split = docId.split(":");
final String type = split[0];
if ("primary".equalsIgnoreCase(type)) {
return Environment.getExternalStorageDirectory() + "/" + split[1];
}
// TODO handle non-primary volumes
}
// DownloadsProvider
else if (isDownloadsDocument(uri)) {
final String id = DocumentsContract.getDocumentId(uri);
final Uri contentUri = ContentUris.withAppendedId(
Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));
return getDataColumn(context, contentUri, null, null);
}
// MediaProvider
else if (isMediaDocument(uri)) {
final String docId = DocumentsContract.getDocumentId(uri);
final String[] split = docId.split(":");
final String type = split[0];
Uri contentUri = null;
if ("image".equals(type)) {
contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
} else if ("video".equals(type)) {
contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
} else if ("audio".equals(type)) {
contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
}
final String selection = "_id=?";
final String[] selectionArgs = new String[] {
split[1]
};
return getDataColumn(context, contentUri, selection, selectionArgs);
}
}
// MediaStore (and general)
else if ("content".equalsIgnoreCase(uri.getScheme())) {
return getDataColumn(context, uri, null, null);
}
// File
else if ("file".equalsIgnoreCase(uri.getScheme())) {
return uri.getPath();
}
return null;
}
/**
* Get the value of the data column for this Uri. This is useful for
* MediaStore Uris, and other file-based ContentProviders.
*
* @param context The context.
* @param uri The Uri to query.
* @param selection (Optional) Filter used in the query.
* @param selectionArgs (Optional) Selection arguments used in the query.
* @return The value of the _data column, which is typically a file path.
*/
public static String getDataColumn(Context context, Uri uri, String selection,
String[] selectionArgs) {
Cursor cursor = null;
final String column = "_data";
final String[] projection = {
column
};
try {
cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs,
null);
if (cursor != null && cursor.moveToFirst()) {
final int column_index = cursor.getColumnIndexOrThrow(column);
return cursor.getString(column_index);
}
} finally {
if (cursor != null)
cursor.close();
}
return null;
}
/**
* @param uri The Uri to check.
* @return Whether the Uri authority is ExternalStorageProvider.
*/
public static boolean isExternalStorageDocument(Uri uri) {
return "com.android.externalstorage.documents".equals(uri.getAuthority());
}
/**
* @param uri The Uri to check.
* @return Whether the Uri authority is DownloadsProvider.
*/
public static boolean isDownloadsDocument(Uri uri) {
return "com.android.providers.downloads.documents".equals(uri.getAuthority());
}
/**
* @param uri The Uri to check.
* @return Whether the Uri authority is MediaProvider.
*/
public static boolean isMediaDocument(Uri uri) {
return "com.android.providers.media.documents".equals(uri.getAuthority());
}
}
问题
如何从 URI 获取实际文件路径
答
据我所知，我们不需要从 URI 获取文件路径，因为在大多数情况下，我们可以直接使用 URI 来完成我们的工作（例如 1. 获取位图 2。向服务器发送文件等）
1. 发送到服务器
我们可以仅使用 URI 直接将文件发送到服务器。
使用 URI，我们可以获得 InputStream，我们可以使用 MultiPartEntity 直接将其发送到服务器。
例
/**
* Used to form Multi Entity for a URI (URI pointing to some file, which we got from other application).
*
* @param uri URI.
* @param context Context.
* @return Multi Part Entity.
*/
public MultipartEntity formMultiPartEntityForUri(final Uri uri, final Context context) {
MultipartEntity multipartEntity = new MultipartEntity(HttpMultipartMode.BROWSER_COMPATIBLE, null, Charset.forName("UTF-8"));
try {
InputStream inputStream = mContext.getContentResolver().openInputStream(uri);
if (inputStream != null) {
ContentBody contentBody = new InputStreamBody(inputStream, getFileNameFromUri(uri, context));
multipartEntity.addPart("[YOUR_KEY]", contentBody);
}
}
catch (Exception exp) {
Log.e("TAG", exp.getMessage());
}
return multipartEntity;
}
/**
* Used to get a file name from a URI.
*
* @param uri URI.
* @param context Context.
* @return File name from URI.
*/
public String getFileNameFromUri(final Uri uri, final Context context) {
String fileName = null;
if (uri != null) {
// Get file name.
// File Scheme.
if (ContentResolver.SCHEME_FILE.equals(uri.getScheme())) {
File file = new File(uri.getPath());
fileName = file.getName();
}
// Content Scheme.
else if (ContentResolver.SCHEME_CONTENT.equals(uri.getScheme())) {
Cursor returnCursor =
context.getContentResolver().query(uri, null, null, null, null);
if (returnCursor != null && returnCursor.moveToFirst()) {
int nameIndex = returnCursor.getColumnIndex(OpenableColumns.DISPLAY_NAME);
fileName = returnCursor.getString(nameIndex);
returnCursor.close();
}
}
}
return fileName;
}
2. 从 URI 获取位图
如果 URI 指向图像，那么我们将得到位图，否则为 null：
/**
* Used to create bitmap for the given URI.
* <p>
* 1. Convert the given URI to bitmap.
* 2. Calculate ratio (depending on bitmap size) on how much we need to subSample the original bitmap.
* 3. Create bitmap bitmap depending on the ration from URI.
* 4. Reference - http://stackoverflow.com/questions/3879992/how-to-get-bitmap-from-an-uri
*
* @param context Context.
* @param uri URI to the file.
* @param bitmapSize Bitmap size required in PX.
* @return Bitmap bitmap created for the given URI.
* @throws IOException
*/
public static Bitmap createBitmapFromUri(final Context context, Uri uri, final int bitmapSize) throws IOException {
// 1. Convert the given URI to bitmap.
InputStream input = context.getContentResolver().openInputStream(uri);
BitmapFactory.Options onlyBoundsOptions = new BitmapFactory.Options();
onlyBoundsOptions.inJustDecodeBounds = true;
onlyBoundsOptions.inDither = true;//optional
onlyBoundsOptions.inPreferredConfig = Bitmap.Config.ARGB_8888;//optional
BitmapFactory.decodeStream(input, null, onlyBoundsOptions);
input.close();
if ((onlyBoundsOptions.outWidth == -1) || (onlyBoundsOptions.outHeight == -1)) {
return null;
}
// 2. Calculate ratio.
int originalSize = (onlyBoundsOptions.outHeight > onlyBoundsOptions.outWidth) ? onlyBoundsOptions.outHeight : onlyBoundsOptions.outWidth;
double ratio = (originalSize > bitmapSize) ? (originalSize / bitmapSize) : 1.0;
// 3. Create bitmap.
BitmapFactory.Options bitmapOptions = new BitmapFactory.Options();
bitmapOptions.inSampleSize = getPowerOfTwoForSampleRatio(ratio);
bitmapOptions.inDither = true;//optional
bitmapOptions.inPreferredConfig = Bitmap.Config.ARGB_8888;//optional
input = context.getContentResolver().openInputStream(uri);
Bitmap bitmap = BitmapFactory.decodeStream(input, null, bitmapOptions);
input.close();
return bitmap;
}
/**
* For Bitmap option inSampleSize - We need to give value in power of two.
*
* @param ratio Ratio to be rounded of to power of two.
* @return Ratio rounded of to nearest power of two.
*/
private static int getPowerOfTwoForSampleRatio(final double ratio) {
int k = Integer.highestOneBit((int) Math.floor(ratio));
if (k == 0) return 1;
else return k;
}
评论
- Android 没有提供任何从 URI 获取文件路径的方法，在上面的大多数答案中，我们已经硬编码了一些常量，这些常量可能会在功能发布中中断（对不起，我可能是错的）。
- 在直接转到从 URI 获取文件路径的解决方案之前，请尝试是否可以使用 URI 和 Android 默认方法解决您的用例。
参考
- https://developer.android.com/guide/topics/providers/content-provider-basics.html
- https://developer.android.com/reference/android/content/ContentResolver.html
- https://hc.apache.org/httpcomponents-client-ga/httpmime/apidocs/org/apache/http/entity/mime/content/InputStreamBody.html
这个 Android 库处理 KitKat（包括旧版本 - 2.1+）中的大小写更改：
https://github.com/iPaulPro/aFileChooser
使用String path = FileUtils.getPath(context, uri)将返回的 Uri 转换为可在所有操作系统版本上使用的路径字符串。在此处查看更多信息：https://stackoverflow.com/a/20559175/860488
对于那些仍在Android SDK版本23及更高版本中使用@Paul Burke代码的用户，如果您的项目遇到错误，说您缺少EXTERNAL_PERMISSION，并且您非常确定已经在AndroidManifest.xml文件中添加了用户权限。这是因为您可能在Android API 23或更高版本中，并且Google在运行时执行访问文件的操作时，有必要再次保证权限。
这意味着：如果您的SDK版本为23或更高版本，则在选择图片文件并想知道其URI时，系统会要求您提供READ&WRITE权限。
以下是我的代码，除了Paul Burke的解决方案。我添加了这些代码，我的项目开始正常工作。
private static final int REQUEST_EXTERNAL_STORAGE = 1;
private static final String[] PERMISSINOS_STORAGE = {
Manifest.permission.READ_EXTERNAL_STORAGE,
Manifest.permission.WRITE_EXTERNAL_STORAGE
};
public static void verifyStoragePermissions(Activity activity) {
int permission = ActivityCompat.checkSelfPermission(activity, Manifest.permission.WRITE_EXTERNAL_STORAGE);
if (permission != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(
activity,
PERMISSINOS_STORAGE,
REQUEST_EXTERNAL_STORAGE
);
}
}
在您的活动和片段中，您要求输入 URI：
private void pickPhotoFromGallery() {
CompatUtils.verifyStoragePermissions(this);
Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setType("image/*");
// startActivityForResult(intent, REQUEST_PHOTO_LIBRARY);
startActivityForResult(Intent.createChooser(intent, "选择照片"),
REQUEST_PHOTO_LIBRARY);
}
就我而言，CompatUtils.java是我定义verifyStoragePermissions方法的地方（作为静态类型，以便我可以在其他活动中调用它）。
此外，在调用 verifyStoragePermissions 方法之前，如果您先创建 if 状态以查看当前 SDK 版本是否高于 23，应该更有意义。
这就是我所做的：
Uri selectedImageURI = data.getData(); imageFile = new File(getRealPathFromURI(selectedImageURI)); private String getRealPathFromURI(Uri contentURI) { Cursor cursor = getContentResolver().query(contentURI, null, null, null, null); if (cursor == null) { // Source is Dropbox or other similar local file path return contentURI.getPath(); } else { cursor.moveToFirst(); int idx = cursor.getColumnIndex(MediaStore.Images.ImageColumns.DATA); return cursor.getString(idx); } }注意：
managedQuery()方法已弃用，所以我不使用它。
这个答案来自 m3n0R 关于问题 android 通过 Uri.getPath（） 获取真实路径，我不主张任何信用。我只是认为还没有解决这个问题的人可以使用这个。
我在这里尝试了几个答案，我想我有一个解决方案，每次都可以工作并管理权限。
它基于LEO的聪明解决方案。这篇文章应该包含完成这项工作所需的所有代码，并且它应该适用于任何手机和Android版本;)
为了能够从 SD 卡中选取文件，您需要在清单中提供以下信息：
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
常数：
private static final int PICK_IMAGE = 456; // Whatever number you like
public static final int MY_PERMISSIONS_REQUEST_READ_EXTERNAL = 28528; // Whatever number you like
public static final String FILE_TEMP_NAME = "temp_image"; // Whatever file name you like
检查权限并启动图像选择（如果可能）
if (ContextCompat.checkSelfPermission(getThis(),
Manifest.permission.READ_EXTERNAL_STORAGE)
!= PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(getThis(),
new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},
MY_PERMISSIONS_REQUEST_READ_EXTERNAL);
}
else {
launchImagePick();
}
权限响应
@Override
public void onRequestPermissionsResult(int requestCode,
@NonNull
String permissions[],
@NonNull
int[] grantResults) {
if (manageReadExternalPermissionResponse(this, requestCode, grantResults)) {
launchImagePick();
}
}
管理权限响应
public static boolean manageReadExternalPermissionResponse(final Activity activity, int requestCode, int[] grantResults) {
if (requestCode == MY_PERMISSIONS_REQUEST_READ_EXTERNAL) {
// If request is cancelled, the result arrays are empty.
if (grantResults.length > 0
&& grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// Permission was granted, yay! Do the
// contacts-related task you need to do.
return true;
} else if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_DENIED) {
boolean showRationale = ActivityCompat.shouldShowRequestPermissionRationale(activity,
Manifest.permission.READ_EXTERNAL_STORAGE);
if (!showRationale) {
// The user also CHECKED "never ask again".
// You can either enable some fall back,
// disable features of your app
// or open another dialog explaining
// again the permission and directing to
// the app setting.
} else {
// The user did NOT check "never ask again".
// This is a good place to explain the user
// why you need the permission and ask if he/she wants
// to accept it (the rationale).
}
} else {
// Permission denied, boo! Disable the
// functionality that depends on this permission.
}
}
return false;
}
启动图像拾取
private void launchImagePick() {
Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setType("image/*");
intent.addCategory(Intent.CATEGORY_OPENABLE);
startActivityForResult(intent, PICK_IMAGE);
// see onActivityResult
}
管理图像选取响应
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == PICK_IMAGE) {
if (resultCode == Activity.RESULT_OK) {
if (data != null && data.getData() != null) {
try {
InputStream inputStream = getContentResolver().openInputStream(data.getData())
if (inputStream != null) {
// No special persmission needed to store the file like that
FileOutputStream fos = openFileOutput(FILE_TEMP_NAME, Context.MODE_PRIVATE);
final int BUFFER_SIZE = 1 << 10 << 3; // 8 KiB buffer
byte[] buffer = new byte[BUFFER_SIZE];
int bytesRead = -1;
while ((bytesRead = inputStream.read(buffer)) > -1) {
fos.write(buffer, 0, bytesRead);
}
inputStream.close();
fos.close();
File tempImageFile = new File(getFilesDir()+"/"+FILE_TEMP_NAME);
// Do whatever you want with the File
// Delete when not needed anymore
deleteFile(FILE_TEMP_NAME);
}
}
catch (Exception e) {
e.printStackTrace();
}
} else {
// Error display
}
} else {
// The user did not select any image
}
}
}
这就是所有人;这在我拥有的所有电话上都对我有用。
如果有人感兴趣，我为 ACTION_GET_CONTENT 制作了一个有效的 Kotlin 版本：
var path: String = uri.path // uri = any content Uri
val databaseUri: Uri
val selection: String?
val selectionArgs: Array<String>?
if ("/document/image:" in path || "/document/image%3A" in path) {
// files selected from "Documents"
databaseUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI
selection = "_id=?"
selectionArgs = arrayOf(DocumentsContract.getDocumentId(uri).split(":")[1])
} else { // files selected from all other sources, especially on Samsung devices
databaseUri = uri
selection = null
selectionArgs = null
}
try {
val projection = arrayOf(MediaStore.Images.Media.DATA,
MediaStore.Images.Media._ID,
MediaStore.Images.Media.ORIENTATION,
MediaStore.Images.Media.DATE_TAKEN) // some example data you can query
val cursor = context.contentResolver.query(databaseUri,
projection, selection, selectionArgs, null)
if (cursor.moveToFirst()) {
// do whatever you like with the data
}
cursor.close()
} catch (e: Exception) {
Log.e(TAG, e.message, e)
}
请尽量避免使用 takePersistableUriPermission 方法，因为它为我引发了运行时异常。/** * 从图库中选择。 */
public void selectFromGallery() {
if (Build.VERSION.SDK_INT < AppConstants.KITKAT_API_VERSION) {
Intent intent = new Intent();
intent.setType("image/*");
intent.setAction(Intent.ACTION_GET_CONTENT);
((Activity)mCalledContext).startActivityForResult(intent,AppConstants.GALLERY_INTENT_CALLED);
} else {
Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setType("image/*");
((Activity)mCalledContext).startActivityForResult(intent, AppConstants.GALLERY_AFTER_KITKAT_INTENT_CALLED);
}
}
用于处理图像数据的结果的活动：
@Override protected void onActivityResult（int requestCode， int resultCode， Intent data） {
//gallery intent result handling before kit-kat version
if(requestCode==AppConstants.GALLERY_INTENT_CALLED
&& resultCode == RESULT_OK) {
Uri selectedImage = data.getData();
String[] filePathColumn = {MediaStore.Images.Media.DATA};
Cursor cursor = getContentResolver().query(selectedImage,filePathColumn, null, null, null);
cursor.moveToFirst();
int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
String filePath = cursor.getString(columnIndex);
cursor.close();
photoFile = new File(filePath);
mImgCropping.startCropImage(photoFile,AppConstants.REQUEST_IMAGE_CROP);
}
//gallery intent result handling after kit-kat version
else if (requestCode == AppConstants.GALLERY_AFTER_KITKAT_INTENT_CALLED
&& resultCode == RESULT_OK) {
Uri selectedImage = data.getData();
InputStream input = null;
OutputStream output = null;
try {
//converting the input stream into file to crop the
//selected image from sd-card.
input = getApplicationContext().getContentResolver().openInputStream(selectedImage);
try {
photoFile = mImgCropping.createImageFile();
} catch (IOException e) {
e.printStackTrace();
}catch(Exception e) {
e.printStackTrace();
}
output = new FileOutputStream(photoFile);
int read = 0;
byte[] bytes = new byte[1024];
while ((read = input.read(bytes)) != -1) {
try {
output.write(bytes, 0, read);
} catch (IOException e) {
e.printStackTrace();
}
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
}
这是一个彻头彻尾的黑客，但这是我所做的......
因此，在设置 DocumentsProvider 时，我注意到示例代码（在 getDocIdForFile 中，大约第 450 行）根据文件相对于您为其提供的指定根的（唯一）路径（即您在第 96 行设置mBaseDir的内容）为所选文档生成唯一 ID。
因此，URI 最终看起来像这样：
content://com.example.provider/document/root:path/to/the/file
正如文档所说，它只假设一个根（在我的情况下，这很Environment.getExternalStorageDirectory()但你可以在其他地方使用......然后它采用文件路径，从根目录开始，并使其成为唯一ID，在"root:"前面。 因此，我可以通过从uri.getPath（）中删除"/document/root:"部分来确定路径，通过执行以下操作来创建实际的文件路径：
public void onActivityResult(int requestCode, int resultCode, Intent data) {
// check resultcodes and such, then...
uri = data.getData();
if (uri.getAuthority().equals("com.example.provider")) {
String path = Environment.getExternalStorageDirectory(0.toString()
.concat("/")
.concat(uri.getPath().substring("/document/root:".length())));
doSomethingWithThePath(path); }
else {
// another provider (maybe a cloud-based service such as GDrive)
// created this uri. So handle it, or don't. You can allow specific
// local filesystem providers, filter non-filesystem path results, etc.
}
我知道。 这是可耻的，但它奏效了。 同样，这依赖于你在应用中使用自己的文档提供程序来生成文档 ID。
（此外，还有一种更好的方法来构建不假设"/"是路径分隔符等的路径。 但你明白了。
这对我来说很好用：
else if(requestCode == GALLERY_ACTIVITY_NEW && resultCode == Activity.RESULT_OK)
{
Uri uri = data.getData();
Log.i(TAG, "old uri = " + uri);
dumpImageMetaData(uri);
try {
ParcelFileDescriptor parcelFileDescriptor =
getContentResolver().openFileDescriptor(uri, "r");
FileDescriptor fileDescriptor = parcelFileDescriptor.getFileDescriptor();
Log.i(TAG, "File descriptor " + fileDescriptor.toString());
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeFileDescriptor(fileDescriptor, null, options);
options.inSampleSize =
BitmapHelper.calculateInSampleSize(options,
User.PICTURE_MAX_WIDTH_IN_PIXELS,
User.PICTURE_MAX_HEIGHT_IN_PIXELS);
options.inJustDecodeBounds = false;
Bitmap bitmap = BitmapFactory.decodeFileDescriptor(fileDescriptor, null, options);
imageViewPic.setImageBitmap(bitmap);
ByteArrayOutputStream stream = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, stream);
// get byte array here
byte[] picData = stream.toByteArray();
ParseFile picFile = new ParseFile(picData);
user.setProfilePicture(picFile);
}
catch(FileNotFoundException exc)
{
Log.i(TAG, "File not found: " + exc.toString());
}
}
在保罗·伯克的回答基础上，我在解析外部SD卡的URI路径时遇到了许多问题，因为大多数建议的"内置"函数返回的路径无法解析为文件。
但是，这是我对他的方法TODO 处理非主卷。
String resolvedPath = "";
File[] possibleExtSdComposites = context.getExternalFilesDirs(null);
for (File f : possibleExtSdComposites) {
// Reset final path
resolvedPath = "";
// Construct list of folders
ArrayList<String> extSdSplit = new ArrayList<>(Arrays.asList(f.getPath().split("/")));
// Look for folder "<your_application_id>"
int idx = extSdSplit.indexOf(BuildConfig.APPLICATION_ID);
// ASSUMPTION: Expected to be found at depth 2 (in this case ExtSdCard's root is /storage/0000-0000/) - e.g. /storage/0000-0000/Android/data/<your_application_id>/files
ArrayList<String> hierarchyList = new ArrayList<>(extSdSplit.subList(0, idx - 2));
// Construct list containing full possible path to the file
hierarchyList.add(tail);
String possibleFilePath = TextUtils.join("/", hierarchyList);
// If file is found --> success
if (idx != -1 && new File(possibleFilePath).exists()) {
resolvedPath = possibleFilePath;
break;
}
}
if (!resolvedPath.equals("")) {
return resolvedPath;
} else {
return null;
}
请注意，这取决于每个手机制造商可能不同的层次结构 - 我还没有测试过它们（到目前为止，它在Xperia Z3 API 23和三星Galaxy A3 API 23上运行良好）。
请确认它是否在其他地方表现不佳。
表示这种类型的 uricontent://com.android.providers.media.documents/document/document%3A19298或uri.getAuthority()是其中任何一个
"com.google.android.apps.docs.storage".equals(uri.getAuthority()) || "com.google.android.apps.docs.storage.legacy".equals(uri.getAuthority());
使用此函数
private static String getDriveFilePath(Uri uri, Context context) {
Uri returnUri = uri;
Cursor returnCursor = context.getContentResolver().query(returnUri, null, null, null, null);
int nameIndex = returnCursor.getColumnIndex(OpenableColumns.DISPLAY_NAME);
int sizeIndex = returnCursor.getColumnIndex(OpenableColumns.SIZE);
returnCursor.moveToFirst();
String name = (returnCursor.getString(nameIndex));
String size = (Long.toString(returnCursor.getLong(sizeIndex)));
File file = new File(context.getCacheDir(), name);
try {
InputStream inputStream = context.getContentResolver().openInputStream(uri);
FileOutputStream outputStream = new FileOutputStream(file);
int read = 0;
int maxBufferSize = 1 * 1024 * 1024;
int bytesAvailable = inputStream.available();
//int bufferSize = 1024;
int bufferSize = Math.min(bytesAvailable, maxBufferSize);
final byte[] buffers = new byte[bufferSize];
while ((read = inputStream.read(buffers)) != -1) {
outputStream.write(buffers, 0, read);
}
Log.e("File Size", "Size " + file.length());
inputStream.close();
outputStream.close();
Log.e("File Path", "Path " + file.getPath());
Log.e("File Size", "Size " + file.length());
} catch (Exception e) {
Log.e("Exception", e.getMessage());
}
return file.getPath();
}
@paul Burke 的答案适用于 API 级别 19 及更高版本的相机和图库图片，但如果 Android 项目的最低 SDK 设置为低于 19，并且上面引用的某些答案不适用于图库和相机。好吧，我已经修改了 @paul burke 的代码，该代码适用于 19 以下的 API 级别。下面是代码。
public static String getPath(final Context context, final Uri uri) {
final boolean isKitKat = Build.VERSION.SDK_INT >=
Build.VERSION_CODES.KITKAT;
Log.i("URI",uri+"");
String result = uri+"";
// DocumentProvider
// if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {
if (isKitKat && (result.contains("media.documents"))) {
String[] ary = result.split("/");
int length = ary.length;
String imgary = ary[length-1];
final String[] dat = imgary.split("%3A");
final String docId = dat[1];
final String type = dat[0];
Uri contentUri = null;
if ("image".equals(type)) {
contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
}
else if ("video".equals(type)) {
}
else if ("audio".equals(type)) {
}
final String selection = "_id=?";
final String[] selectionArgs = new String[] {
dat[1]
};
return getDataColumn(context, contentUri, selection, selectionArgs);
}
else
if ("content".equalsIgnoreCase(uri.getScheme())) {
return getDataColumn(context, uri, null, null);
}
// File
else if ("file".equalsIgnoreCase(uri.getScheme())) {
return uri.getPath();
}
return null;
}
public static String getDataColumn(Context context, Uri uri, String selection,
String[] selectionArgs) {
Cursor cursor = null;
final String column = "_data";
final String[] projection = {
column
};
try {
cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs,
null);
if (cursor != null && cursor.moveToFirst()) {
final int column_index = cursor.getColumnIndexOrThrow(column);
return cursor.getString(column_index);
}
}
finally {
if (cursor != null)
cursor.close();
}
return null;
}
您的问题的答案是您需要具有权限。在清单.xml文件中键入以下代码：
<uses-sdk android:minSdkVersion="8" android:targetSdkVersion="18" />
<uses-permission android:name="android.permission.READ_CONTACTS" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>
<uses-permission android:name="android.permission.WRITE_OWNER_DATA"></uses-permission>
<uses-permission android:name="android.permission.READ_OWNER_DATA"></uses-permission>`
它对我有用...