BitmapFactory无法解码流

Question

嘿，我不确定为什么每次我在我的图库中选择一张图片时都会出现这个问题？

代码如下：

if (v == uploadImageButton) {
                        // below allows you to open the phones gallery
                        Intent intent = new Intent();
                        intent.setType("image/*");
                        intent.setAction(Intent.ACTION_GET_CONTENT);
                        startActivityForResult(
                                        Intent.createChooser(intent, "Complete action using"), 1);
                }


public void onActivityResult(int requestCode, int resultCode, Intent data) {
                if (resultCode == RESULT_OK && requestCode == 1 && null != data) {
                        // Bitmap photo = (Bitmap) data.getData().getPath();
                        Uri selectedImageUri = data.getData();
                        String[] filePathColumn = { MediaStore.Images.Media.DATA };

                        Cursor cursor = getContentResolver().query(selectedImageUri,
                                        filePathColumn, null, null, null);
                        cursor.moveToFirst();

                        int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
                        String picturePath = cursor.getString(columnIndex);
                        cursor.close();
                        Log.e("Picture", picturePath);
                        decodeFile(picturePath);
                }
        }


public void decodeFile(String filePath) {
                // TODO Auto-generated method stub
                // Decode image size
                BitmapFactory.Options o = new BitmapFactory.Options();
                o.inJustDecodeBounds = true;
                BitmapFactory.decodeFile(filePath, o);

                // the new size we want to scale to
                final int REQUIRED_SIZE = 1024;

                // 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 < REQUIRED_SIZE && height_tmp < REQUIRED_SIZE) {
                                break;
                        }
                        width_tmp /= 2;
                        height_tmp /= 2;
                        scale *= 2;
                }

                // decode with inSampleSize
                BitmapFactory.Options o2 = new BitmapFactory.Options();
                o2.inSampleSize = scale;
                Bitmap bitmap = BitmapFactory.decodeFile(filePath, o2);

                imageview.setImageBitmap(bitmap);
        }

错误：

01-17 23:18:04.642: D/Documents(25157): onFinished() [content://com.android.providers.media.documents/document/image%3A901]
01-17 23:18:04.682: E/BitmapFactory(24993): Unable to decode stream: java.lang.NullPointerException
01-17 23:18:04.682: E/BitmapFactory(24993): Unable to decode stream: java.lang.NullPointerException
01-17 23:18:09.732: I/InputReader(766): Reconfiguring input devices.  changes=0x00000004
01-17 23:18:09.732: I/InputReader(766): Device reconfigured: id=4, name='touch_dev', size 1080x1920, orientation 3, mode 1, display id 0

Answer 1

不要假设有一个文件路径。Android 4.4和更高版本即将移除它们。而且你得到的uri已经没有路径了。

您仍然可以通过InputStream (ContentResolver#openInputStream(Uri uri))或文件描述符访问文件内容。

在这里解释：ContentProviders: Open a document (向下滚动，链接到部分似乎是断开的)

这也适用于较老的android版本。

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (resultCode == RESULT_OK && requestCode == 1 && null != data) {
        decodeUri(data.getData());
    }
}

public void decodeUri(Uri uri) {
    ParcelFileDescriptor parcelFD = null;
    try {
        parcelFD = getContentResolver().openFileDescriptor(uri, "r");
        FileDescriptor imageSource = parcelFD.getFileDescriptor();

        // Decode image size
        BitmapFactory.Options o = new BitmapFactory.Options();
        o.inJustDecodeBounds = true;
        BitmapFactory.decodeFileDescriptor(imageSource, null, o);

        // the new size we want to scale to
        final int REQUIRED_SIZE = 1024;

        // 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 < REQUIRED_SIZE && height_tmp < REQUIRED_SIZE) {
                break;
            }
            width_tmp /= 2;
            height_tmp /= 2;
            scale *= 2;
        }

        // decode with inSampleSize
        BitmapFactory.Options o2 = new BitmapFactory.Options();
        o2.inSampleSize = scale;
        Bitmap bitmap = BitmapFactory.decodeFileDescriptor(imageSource, null, o2);

        imageview.setImageBitmap(bitmap);

    } catch (FileNotFoundException e) {
        // handle errors
    } catch (IOException e) {
        // handle errors
    } finally {
        if (parcelFD != null)
            try {
                parcelFD.close();
            } catch (IOException e) {
                // ignored
            }
    }
}