是否在成员变量中保存图像文件路径

Question

我正在尝试创建一个简单的Contact应用程序。自然存在具有成员变量mCurrentPhotoPath的Contact类。负责创建联系人的活动可以通过以下方式从Gallery中选择图像：

final Intent pickImage = new Intent(Intent.ACTION_GET_CONTENT);
pickImage.setType("image/*")
/*some code...*/
galleryButton.setOnClickListener((View v) -> {
startActivityForResult(pickImage, REQUEST_GALLERY_PHOTO);
});
@Override
public void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == REQUEST_GALLERY_PHOTO && resultCode == RESULT_OK){
photoTaken = true;
Uri selectedImage = data.getData();
Log.i("path", selectedImage.getPath()) //prints out: /document/image:292562
mPhotoView.setImageURI(selectedImage);

我能够在ImageView(mPhotoView(中显示所选图像。

然而，当我尝试以不同的方式设置Intent时，我会得到完整的路径，但我无法从该路径重新创建文件，我会获得FileNotFoundException。

final Intent pickImage = new Intent(Intent.ACTION_PICK,android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
@Override
public void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == REQUEST_GALLERY_PHOTO && resultCode == RESULT_OK){
photoTaken = true;
Uri selectedImage = data.getData();
String[] filePathColumn = {MediaStore.Images.Media.DATA};
if (selectedImage != null) {
Cursor cursor = getContentResolver().query(selectedImage, filePathColumn, null, null, null);
if (cursor != null) {
cursor.moveToFirst();
int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
String picturePath = cursor.getString(columnIndex);
Log.i.("TAG", picturePath); //I get, /storage/emulated/0/Pictures/Viber/IMG-bbd54c96cc971a1700f92205937014c8-V.jpg
mPhotoFile = new File(picturePath);
cursor.close();
updatePhotoView(); //This method recreates image based on exact file path and witdh & height of ImageView where the picture is going to be placed;
}
}
}

这是updatePhotoView()

private void updatePhotoView(int imageWidth, int imageHeight) {
if (mPhotoFile == null || !mPhotoFile.exists()) {
mPhotoView.setImageDrawable(null);
} else {
Bitmap bitmap = PictureUtils.getScaledBitmap(mPhotoFile.getPath(),imageWidth, imageHeight); // imageWidth & imageHeight are member variables of actiivty...
mPhotoView.setImageBitmap(bitmap);
}
}

我非常确信这个函数是有效的，因为当我实现从相机拍照的选项时(我用getExternalFilesDir((创建了文件，在任何其他活动中，当我传递字符串值mCurrentPhotoPath时，getScaledBitmap()成功地重新创建了图像(。

这里是getScaledBitmap():

public static Bitmap getScaledBitmap(String path, int destWidth, int destHeight) {
// Read in the dimensions of the image on disk
BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(path, options);
float srcWidth = options.outWidth;
float srcHeight = options.outHeight;
// Figure out how much to scale down by
int inSampleSize = 1;
if (srcHeight > destHeight || srcWidth > destWidth) {
if (srcWidth > srcHeight) {
inSampleSize = Math.round(srcHeight / destHeight);
} else {
inSampleSize = Math.round(srcWidth / destWidth);
}
}
options = new BitmapFactory.Options();
options.inSampleSize = inSampleSize;
// Read in and create final bitmap
return BitmapFactory.decodeFile(path, options);
}

Answer 1

如果有人遇到类似的问题。我使用Glide库解决了获取图像的问题。查一下，一堆教程。我猜这个load函数在后台做繁重的工作。太棒了！以下是代码的样子：

Glide.with(context)
.load(imageFilePath)
.apply(new RequestOptions().centerCrop())
.override(imageView.getWidth(), imageView.getHeight())
.into(imageView);