我正在从图库中选择图像。我想以kb或mb为单位编程地确定图像的大小。这是我写的:
public String calculateFileSize(Uri filepath)
{
//String filepathstr=filepath.toString();
File file = new File(filepath.getPath());
// Get length of file in bytes
long fileSizeInBytes = file.length();
// Convert the bytes to Kilobytes (1 KB = 1024 Bytes)
long fileSizeInKB = fileSizeInBytes / 1024;
// Convert the KB to MegaBytes (1 MB = 1024 KBytes)
long fileSizeInMB = fileSizeInKB / 1024;
String calString=Long.toString(fileSizeInMB);
return calString;
}
从图库中选择图像的uri是完美的。但是fileSizeInBytes的值是0。在从图库中选择图像后，我在onActivityResult上调用此方法。我之前在这里看到了一些同样的问题。但没有一个对我有用。有解决方案吗?
变化
public String calculateFileSize(Uri filepath)
{
//String filepathstr=filepath.toString();
File file = new File(filepath.getPath());
long fileSizeInKB = fileSizeInBytes / 1024;
// Convert the KB to MegaBytes (1 MB = 1024 KBytes)
long fileSizeInMB = fileSizeInKB / 1024;
String calString=Long.toString(fileSizeInMB);
public String calculateFileSize(String filepath)
{
//String filepathstr=filepath.toString();
File file = new File(filepath);
float fileSizeInKB = fileSizeInBytes / 1024;
// Convert the KB to MegaBytes (1 MB = 1024 KBytes)
float fileSizeInMB = fileSizeInKB / 1024;
String calString=Float.toString(fileSizeInMB);
当你使用long时，它将截断.之后的所有数字，所以如果你的大小小于1MB，你将得到0。
用float代替long
试试这个，它会为你工作的
private void getImageSize(Uri choosen) throws IOException {
Bitmap bitmap = MediaStore.Images.Media.getBitmap(this.getContentResolver(), choosen);
ByteArrayOutputStream stream = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, stream);
byte[] imageInByte = stream.toByteArray();
long lengthbmp = imageInByte.length;
Toast.makeText(getApplicationContext(),Long.toString(lengthbmp),Toast.LENGTH_SHORT).show();
}
And on result
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
switch(requestCode) {
case SELECT_PHOTO:
if(resultCode == RESULT_OK){
Uri selectedImage = data.getData();
if(selectedImage !=null){
img.setImageURI(selectedImage);
try {
getImageSize(choosenPhoto);
} catch (IOException e) {
e.printStackTrace();
}
//txt1.setText("Initial size: " +getImageSize(choosenPhoto)+ " Kb");
}
}
}
}
这是计算从图库中选择的图像大小的方法。你可以在onActivityResult:
中传递你从intent获得的Uripublic static double getImageSizeFromUriInMegaByte(Context context, Uri uri) {
String scheme = uri.getScheme();
double dataSize = 0;
if (scheme.equals(ContentResolver.SCHEME_CONTENT)) {
try {
InputStream fileInputStream = context.getContentResolver().openInputStream(uri);
if (fileInputStream != null) {
dataSize = fileInputStream.available();
}
} catch (Exception e) {
e.printStackTrace();
}
} else if (scheme.equals(ContentResolver.SCHEME_FILE)) {
String path = uri.getPath();
File file = null;
try {
file = new File(path);
} catch (Exception e) {
e.printStackTrace();
}
if (file != null) {
dataSize = file.length();
}
}
return dataSize / (1024 * 1024);
}
用uri.getLastPathSegment()代替uri.getPath()
public static float getImageSize(Uri uri) {
File file = new File(uri.getLastPathSegment());
return file.length(); // returns size in bytes
}
重要的
上面的代码只适用于你从图库中挑选的图片;并且对于那些来自文件管理器的不起作用，因为它不会识别URI
的模式下面的方法在两种情况下都有效
public static float getImageSize(Context context, Uri uri) {
Cursor cursor = context.getContentResolver().query(uri, null, null, null, null);
if (cursor != null) {
int sizeIndex = cursor.getColumnIndex(OpenableColumns.SIZE);
cursor.moveToFirst();
float imageSize = cursor.getLong(sizeIndex);
cursor.close();
return imageSize; // returns size in bytes
}
return 0;
}
将bytes改为Kbytes>>/1024f
将bytes改为mb>>>/(1024f * 1024f)
private boolean validImageSize() {
try {
if (bitmapPhoto!=null){
ByteArrayOutputStream stream = new ByteArrayOutputStream();
bitmapPhoto.compress(Bitmap.CompressFormat.PNG, 100, stream);
byte[] imageInByte = stream.toByteArray();
// Get length of file in bytes
float imageSizeInBytes = imageInByte.length;
// Convert the bytes to Kilobytes (1 KB = 1024 Bytes)
float imageSizeInKB = imageSizeInBytes / 1024;
// Convert the KB to MegaBytes (1 MB = 1024 KBytes)
float imageSizeInMB = imageSizeInKB / 1024;
return imageSizeInMB <= 1;
}else {
return true;
}
}catch (Exception e){
e.printStackTrace();
return true;
}
}
试试这个，它会从新的android和旧的uri返回到你的文件
fun getFileFromUri(uri: Uri): File? {
if (uri.path == null) {
return null
}
var realPath = String()
val databaseUri: Uri
val selection: String?
val selectionArgs: Array<String>?
if (uri.path!!.contains("/document/image:")) {
databaseUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI
selection = "_id=?"
selectionArgs = arrayOf(DocumentsContract.getDocumentId(uri).split(":")[1])
} else {
databaseUri = uri
selection = null
selectionArgs = null
}
try {
val column = "_data"
val projection = arrayOf(column)
val cursor = context.contentResolver.query(
databaseUri,
projection,
selection,
selectionArgs,
null
)
cursor?.let {
if (it.moveToFirst()) {
val columnIndex = cursor.getColumnIndexOrThrow(column)
realPath = cursor.getString(columnIndex)
}
cursor.close()
}
} catch (e: Exception) {
Log.i("GetFileUri Exception:", e.message ?: "")
}
val path = if (realPath.isNotEmpty()) realPath else {
when {
uri.path!!.contains("/document/raw:") -> uri.path!!.replace(
"/document/raw:",
""
)
uri.path!!.contains("/document/primary:") -> uri.path!!.replace(
"/document/primary:",
"/storage/emulated/0/"
)
else -> return null
}
}
return File(path)}
之后你可以用这个来获取文件大小
val file = getFileFromUri(your_uri)
val file_size = Integer.parseInt(String.valueOf(file.length()/1024))
在最近的Android版本中，访问直接文件有许多限制。我们可以使用ContentProviders从Uri获取大小。这里引用
fun getFileSize(uri: Uri): Long {
val cursor: Cursor? = context.contentResolver!!.query(
yourFileUri, null, null, null, null
)
cursor?.use {
val sizeColumn =
it.getColumnIndexOrThrow(android.provider.MediaStore.MediaColumns.SIZE)
if (it.moveToNext()) {
return it.getLong(sizeColumn)
}
}
return 0L
}
你也可以使用下面的函数来设置
的大小android.text.format.Formatter。formatFileSize(背景:背景?， sizeBytes: Long): String!