android - 将图像传递给另一个 Activity

Question

多亏了这个网站，我弄清楚了如何在 Activity 之间传递字符串值，但是我在传递图像时遇到了问题。我想要做的是让用户点击一个按钮打开图库并允许选择图片。然后我有另一个按钮打开另一个显示 ImageView 的 Activity 。我希望能够让 ImageView 的图像成为从上一个 Activity 中选择的图像。

这是具有我单击以打开图库并检索所选图像的按钮的类:

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);
    }
   }
 }
}

这里是应该显示所选图像的类:

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); 
 }
}

如果我应该传递 selectedImage 或 b.putExtra("bitmap", selectedimage); 行。我都试过了，但我没有看到第二个 Activity 的图像。此外，我不确定在 PreviewScreen 类中是否正确设置了 imageview。任何帮助表示赞赏。谢谢。

Answer 1

相信我，您不想在 Activity 之间传递图像。相反，为什么不简单地传递图像的路径并让第二个 Activity 决定如何处理该路径(在本例中解码和显示图像)。