Passing image to another activity

问题:

I figured out how to pass a String value between activites thanks to this site, however I'm having trouble passing an image. What I'm trying to to is have a user click a button that opens the gallery and allows selecting of a picture. Then I have another button that opens another activity that displays an ImageView. I want to be able to have that ImageView's image be the chosen one from the previous activity.

Here is the class that has the button I'm clicking to open the gallery and retrieve the chosen image:

public class EnterEdit extends Activity implements View.OnClickListener 
{
private static final int SELECT_IMAGE = 0;

 String filepath;

 Bundle fieldresults;
 Intent b; 

 @Override
 protected void onCreate(Bundle savedInstanceState)
 {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.enteredit);

  Button selectwallpaper = (Button) findViewById(R.id.selectwallpaper);
  selectwallpaper.setOnClickListener(this);

  Button previewwallpaper = (Button) findViewById(R.id.previewwallpaper);
  previewwallpaper.setOnClickListener(this);

  fieldresults = new Bundle();
  b = new Intent(this, PreviewScreen.class);
 }


 @Override
 public void onClick(View view) 
 {
  switch (view.getId())
  {
   case R.id.selectwallpaper:
    Intent gallery = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.INTERNAL_CONTENT_URI);
    startActivityForResult(gallery, SELECT_IMAGE);
    break;

   case R.id.previewwallpaper:
     startActivity(b); 
    }
    break;   
  }


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

   if (resultCode == RESULT_OK)
   {
    if (requestCode == SELECT_IMAGE)
    {
     Uri selectedimage = data.getData();
     String[] filepathcolumn = {MediaStore.Images.Media.DATA};

     Cursor cursor = getContentResolver().query(selectedimage, filepathcolumn, null, null, null);
     cursor.moveToFirst();

     int columnindex = cursor.getColumnIndex(filepathcolumn[0]);
     filepath = cursor.getString(columnindex);
     cursor.close();

     fieldresults.putString("bitmap", filepath);
     b.putExtras(fieldresults);
    }
   }
 }
}

And here is the class that should display the chosen image:

public class PreviewScreen extends Activity implements View.OnClickListener 
{

 @Override
 protected void onCreate(Bundle savedInstanceState)
 {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.previewscreen);

  Bundle fieldresults = this.getIntent().getExtras();
  String backgroundpath = fieldresults.getString("bitmap");

  String background = BitmapFactory.decodeFile(backgroundpath);
  ImageView gallerypic = (ImageView) findViewById(R.id.gallerypic);
  gallerypic.setImageBitmap(background); 
 }
}

What I'm not sure about is in the OnActivityResult if I should pass the selectedImage or the chosenimage in the b.putExtra("bitmap", selectedimage); line. I tried both but I didn't see an image on the second activity. Also I wasn't sure in the PreviewScreen class if I'm setting the imageview correctly. Any help is appreciated. Thanks.

回答1:

Trust me, you don't want to be passing images between activities. Rather, why don't you simply pass the path of the image and let the second activity decide what to do with that path (decode and display the image, in this case).