Question

在Samsung Galaxy S4（型号：GT-I9500）上运行一些基本代码时，我遇到了一个具体问题。

我是通过相机或图库实现了一个图像选择器，并且在我的生活中无法弄清楚为什么ImageView在调用时是空白的 -

imageView.setImageURI(uri);

直到我在模拟器中运行完全相同的代码（然后是Nexus 5），才发现这是三星S4问题。

上找到完整的示例项目

我使用的代码取自SO post：

在 OnCreate ：

btn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            AlertDialog.Builder builder = new AlertDialog.Builder(context);
            builder.setTitle("Choose Image Source");
            builder.setItems(new CharSequence[]{"Gallery", "Camera"},
                    new DialogInterface.OnClickListener() {

                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            switch (which) {
                                case 0:

                                    //Launching the gallery
                                    Intent i = new Intent(Intent.ACTION_PICK, MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
                                    startActivityForResult(i, GALLERY);

                                    break;

                                case 1:
                                    //Specify a camera intent
                                    Intent getCameraImage = new Intent("android.media.action.IMAGE_CAPTURE");

                                    File cameraFolder;

                                    //Check to see if there is an SD card mounted
                                    if (android.os.Environment.getExternalStorageState().equals
                                            (android.os.Environment.MEDIA_MOUNTED))
                                        cameraFolder = new File(android.os.Environment.getExternalStorageDirectory(),
                                                IMAGEFOLDER);
                                    else
                                        cameraFolder = MainActivity.this.getCacheDir();
                                    if (!cameraFolder.exists())
                                        cameraFolder.mkdirs();

                                    //Appending timestamp to "picture_"
                                    SimpleDateFormat dateFormat = new SimpleDateFormat("yyyyMMdd'T'HHmmss");
                                    String timeStamp = dateFormat.format(new Date());
                                    String imageFileName = "picture_" + timeStamp + ".jpg";

                                    File photo = new File(Environment.getExternalStorageDirectory(),
                                            IMAGEFOLDER + imageFileName);
                                    getCameraImage.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(photo));

                                    //Setting a global variable to be used in the OnActivityResult
                                    imageURI = Uri.fromFile(photo);

                                    startActivityForResult(getCameraImage, CAMERA);

                                    break;
                                default:
                                    break;
                            }
                        }
                    });

            builder.show();
        }
    });

OnActivityResult ：

protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);

    if (resultCode == RESULT_OK) {


        switch (requestCode) {
            case GALLERY:
                Uri selectedImage = data.getData();
                imageView.setImageURI(selectedImage);

                break;
            case CAMERA:

                imageView.setImageURI(imageURI);
                break;
        }

    }

}

使用 Picasso

时也会发生

 if (resultCode == RESULT_OK) {


        switch (requestCode) {
            case GALLERY:
                Uri selectedImage = data.getData();
                Picasso.with(context)
                        .load(selectedImage)
                        .into(imageView);

                break;
            case CAMERA:
                Picasso.with(context)
                        .load(imageURI)
                        .into(imageView);
                break;
        }

    }

使用Bitmap Factory时也会出现

  try {
                    Bitmap bitmap = BitmapFactory.decodeStream(context.getContentResolver().openInputStream(imageURI));
                    imageView.setImageBitmap(bitmap);
                } catch (FileNotFoundException e) {
                    e.printStackTrace();
                }

enter image description here

在运行4.2.2的三星S4上运行的结果

S4 Before S4 After

在运行Android 4.4.4的GenyMotion 2.4.0上运行时的结果

GenyMotion Before GenyMotion After

任何人都知道为什么会这样吗？

Answer 1

所以问题原来是三星S4处理的图像位图太大了。

令人沮丧的是没有引发任何错误 - 正确的解决方案如下：

switch (requestCode) {
            case GALLERY:
                Bitmap bitmap = createScaledBitmap(getImagePath(data, getApplicationContext()), imageView.getWidth(), imageView.getHeight());
                imageView.setImageBitmap(bitmap);
                break;
            case CAMERA:
                String path = imageURI.getPath();
                Bitmap bitmapCamera = createScaledBitmap(path, imageView.getWidth(), imageView.getHeight());
                imageView.setImageBitmap(bitmapCamera);
                break;
        }

助手方法：

// Function to get image path from ImagePicker
public static String getImagePath(Intent data, Context context) {
    Uri selectedImage = data.getData();
    String[] filePathColumn = {MediaStore.Images.Media.DATA};
    Cursor cursor = context.getContentResolver().query(selectedImage, filePathColumn, null, null, null);
    cursor.moveToFirst();
    int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
    String picturePath = cursor.getString(columnIndex);
    cursor.close();
    return picturePath;
}


public Bitmap createScaledBitmap(String pathName, int width, int height) {
    final BitmapFactory.Options opt = new BitmapFactory.Options();
    opt.inJustDecodeBounds = true;
    BitmapFactory.decodeFile(pathName, opt);
    opt.inSampleSize = calculateBmpSampleSize(opt, width, height);
    opt.inJustDecodeBounds = false;
    return BitmapFactory.decodeFile(pathName, opt);
}

public int calculateBmpSampleSize(BitmapFactory.Options opt, int width, int height) {
    final int outHeight = opt.outHeight;
    final int outWidth = opt.outWidth;
    int sampleSize = 1;
    if (outHeight > height || outWidth > width) {
        final int heightRatio = Math.round((float) outHeight / (float) height);
        final int widthRatio = Math.round((float) outWidth / (float) width);
        sampleSize = heightRatio < widthRatio ? heightRatio : widthRatio;
    }
    return sampleSize;
}

Answer 2

使用Picasso时，请使用fit（）或resize（）。它处理调整位图的大小。

Answer 3

他们是否有机会使用不同的应用程序？ 4.4为图像选择引入了几个新的URI，因为它们可以是本地的，谷歌加等等。

试试这个：BitmapFactory.decodeStream(context.getContentResolver().openInputStream(uri))

它返回一个可以在图像视图中用作

的位图

imgView.setImageBitmap(bitmap)

在Samsung Galaxy S4 Only上运行时，ImageView不会通过setImageURI加载

3 个答案: