private static final int SELECT_PHOTO = 100;

开始的目的

Intent photoPickerIntent = new Intent(Intent.ACTION_PICK);
photoPickerIntent.setType("image/*");
startActivityForResult(photoPickerIntent, SELECT_PHOTO);    

过程的结果

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent imageReturnedIntent) { 
    super.onActivityResult(requestCode, resultCode, imageReturnedIntent); 

    switch(requestCode) { 
    case SELECT_PHOTO:
        if(resultCode == RESULT_OK){  
            Uri selectedImage = imageReturnedIntent.getData();
            InputStream imageStream = getContentResolver().openInputStream(selectedImage);
            Bitmap yourSelectedImage = BitmapFactory.decodeStream(imageStream);
        }
    }
}

或者，你也可以降低你的图像样本，以避免OutOfMemory错误。

private Bitmap decodeUri(Uri selectedImage) throws FileNotFoundException {

        // Decode image size
        BitmapFactory.Options o = new BitmapFactory.Options();
        o.inJustDecodeBounds = true;
        BitmapFactory.decodeStream(getContentResolver().openInputStream(selectedImage), null, o);

        // The new size we want to scale to
        final int REQUIRED_SIZE = 140;

        // Find the correct scale value. It should be the power of 2.
        int width_tmp = o.outWidth, height_tmp = o.outHeight;
        int scale = 1;
        while (true) {
            if (width_tmp / 2 < REQUIRED_SIZE
               || height_tmp / 2 < REQUIRED_SIZE) {
                break;
            }
            width_tmp /= 2;
            height_tmp /= 2;
            scale *= 2;
        }

        // Decode with inSampleSize
        BitmapFactory.Options o2 = new BitmapFactory.Options();
        o2.inSampleSize = scale;
        return BitmapFactory.decodeStream(getContentResolver().openInputStream(selectedImage), null, o2);

    }

像-一样调用chooseImage方法

public void chooseImage(ImageView v)
{
    Intent intent = new Intent(Intent.ACTION_PICK);
    intent.setType("image/*");
    startActivityForResult(intent, SELECT_PHOTO);
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent imageReturnedIntent) {
    // TODO Auto-generated method stub
    super.onActivityResult(requestCode, resultCode, imageReturnedIntent);

    if(imageReturnedIntent != null)
    {
        Uri selectedImage = imageReturnedIntent.getData();
    switch(requestCode) { 
    case SELECT_PHOTO:
        if(resultCode == RESULT_OK)
        {
            Bitmap datifoto = null;
            temp.setImageBitmap(null);
            Uri picUri = null;
            picUri = imageReturnedIntent.getData();//<- get Uri here from data intent
             if(picUri !=null){
               try {
                   datifoto = android.provider.MediaStore.Images.Media.getBitmap(this.getContentResolver(),                                 picUri);
                   temp.setImageBitmap(datifoto);
               } catch (FileNotFoundException e) {
                  throw new RuntimeException(e);
               } catch (IOException e) {
                  throw new RuntimeException(e);
               } catch (OutOfMemoryError e) {
                Toast.makeText(getBaseContext(), "Image is too large. choose other", Toast.LENGTH_LONG).show();
            }

        }
        }
        break;

}
    }
    else
    {
        //Toast.makeText(getBaseContext(), "data null", Toast.LENGTH_SHORT).show();
    }
}

你必须为一个结果开始画廊意图。

Intent i = new Intent(Intent.ACTION_PICK,
               android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(i, ACTIVITY_SELECT_IMAGE); 

然后在onActivityForResult中调用intent.getData()来获取图像的Uri。然后你需要从ContentProvider中获取图像。

这样做可以启动图库，并允许用户选择一张图片:

Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setType("image/*");
startActivityForResult(intent, IMAGE_PICK);

然后在onActivityResult()中使用返回的图像的URI来设置ImageView上的图像。

这是一个图像和视频的测试代码。它也适用于所有小于19和大于19的api。

图片:

if (Build.VERSION.SDK_INT <= 19) {
                        Intent i = new Intent();
                        i.setType("image/*");
                        i.setAction(Intent.ACTION_GET_CONTENT);
                        i.addCategory(Intent.CATEGORY_OPENABLE);
                        startActivityForResult(i, 10);
                    } else if (Build.VERSION.SDK_INT > 19) {
                        Intent intent = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
                        startActivityForResult(intent, 10);
                    }

视频:

if (Build.VERSION.SDK_INT <= 19) {
                        Intent i = new Intent();
                        i.setType("video/*");
                        i.setAction(Intent.ACTION_GET_CONTENT);
                        i.addCategory(Intent.CATEGORY_OPENABLE);
                        startActivityForResult(i, 20);
                    } else if (Build.VERSION.SDK_INT > 19) {
                        Intent intent = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Video.Media.EXTERNAL_CONTENT_URI);
                        startActivityForResult(intent, 20);
                    }    

.

     @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (resultCode == Activity.RESULT_OK) {               
            if (requestCode == 10) {
                Uri selectedImageUri = data.getData();
                String selectedImagePath = getRealPathFromURI(selectedImageUri);
            } else if (requestCode == 20) {
                Uri selectedVideoUri = data.getData();
                String selectedVideoPath = getRealPathFromURI(selectedVideoUri);
            }
        }
     }

     public String getRealPathFromURI(Uri uri) {
            if (uri == null) {
                return null;
            }
            String[] projection = {MediaStore.Images.Media.DATA};
            Cursor cursor = getActivity().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();
        }

由于某些原因，这个线程中的所有答案，在onActivityResult()中尝试对接收到的Uri进行后处理，比如获得图像的真实路径，然后使用BitmapFactory.decodeFile(path)来获得位图。

此步骤无需执行。ImageView类有一个叫做setImageURI(uri)的方法。将您的uri传递给它，您就应该完成了。

Uri imageUri = data.getData();
imageView.setImageURI(imageUri);

完整的工作示例可以在这里查看:http://androidbitmaps.blogspot.com/2015/04/loading-images-in-android-part-iii-pick.html

PS: 在要加载的图像太大而无法装入内存的情况下，在一个单独的变量中获取位图是有意义的，并且需要一个缩小操作来防止OurOfMemoryError，就像@siamii答案中所示的那样。