Android-无法从内置图片库显示图片

Question

I am trying to use Android's built-in gallery. I am able to get the gallery and the albums, but whenever I want to display the image, the gallery straightaway directs me back to my app. I am unable to view the image despite it has been called.

This is my code:

public class CameraTab extends Activity implements OnClickListener{
private static final int SELECT_PICTURE = 1;

private String selectedImagePath;
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.camera_tab);

    ImageButton cameraBtn = (ImageButton)findViewById(R.id.camera_btn);
    cameraBtn.setOnClickListener(this); 

    ImageButton galleryBtn = (ImageButton)findViewById(R.id.gallery_btn);
    galleryBtn.setOnClickListener(this);

}

public void onClick(View v) {
    // TODO Auto-generated method stub

    if (v == this.findViewById(R.id.camera_btn)){
    /// some codes here
    }

    if (v == this.findViewById(R.id.gallery_btn)){
             Intent intent = new Intent();
             intent.setType("image/*");
             intent.setAction(Intent.ACTION_GET_CONTENT);
             startActivityForResult(Intent.createChooser(intent,
                "Select Picture"), SELECT_PICTURE);
    }
}

public void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (resultCode == RESULT_OK) {
        if (requestCode == SELECT_PICTURE) {
            Uri selectedImageUri = data.getData();
            selectedImagePath = getPath(selectedImageUri);           
        }
    }
}

public String getPath(Uri uri) {
    String[] projection = { MediaStore.Images.Media.DATA };
    Cursor cursor = managedQuery(uri, projection, null, null, null);
    int column_index = cursor
            .getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
    cursor.moveToFirst();
    return cursor.getString(column_index);
}

}

Can anyone please help me? Any help would be appreciated!! Thanks!!

Answer 1

I think the Action you want to use is Intent.ACTION_VIEW . try this

final Intent intent = new Intent(Intent.ACTION_VIEW);
final Uri uri = <The URI to your file>;
// Uri either from file eg.
final Uri uri = Uri.fromFile(yourImageFileOnSDCard); 
// or from media store like your method getPath() does but with the URI
// from http://developer.android.com/reference/android/provider/MediaStore.Images.Media.html#EXTERNAL_CONTENT_URI
intent.setDataAndType(uri, "image/*");
startActivity(intent);

The string "image/* is the mime type to be used.

Now the gallery is opened with the given picture selected. To return to your app the user has to press the back button, as usual ;)

Answer 2

private Context context;

public void onCreate(Bundle savedInstanceState) {
...
context = this;
}

I used a scaled Bitmap below because on some devices the images in the Gallery might be too large for being displayed on an ImageView (I had this problem before).

@Override    
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (resultCode == RESULT_OK) {
    if (requestCode == SELECT_PICTURE) {
        Uri selectedImageUri = data.getData();
        selectedImagePath = getPath(selectedImageUri);

        Bitmap b = new BitmapDrawable(context.getResources(),
                selectedImagePath).getBitmap();
        int i = (int) (b.getHeight() * (512.0 / b.getWidth()));
        bitmap = Bitmap.createScaledBitmap(b, 512, i, true);

        // To display the image, you need to set it to an ImageView here
        ImageView img = (ImageView) findViewById(R.id.myImageView);
        img.setImageBitmap(bitmap);
        }
    }
}

Answer 3

The problem is a misunderstanding of Intent.ACTION_GET_CONTENT intent. It's intented to be used to choose a content (in this case image/*) from the archive.

If you want to show an image, just create a new activity with an ImageView in its layout. Pass the image URI using setData .