我需要通过从其他活动中选择图像来动态更改活动的背景。并将所选图像传递回调用活动,但是当我尝试获取图像时,它为空。这是我的代码。
public class SelectGoalBackground extends OrmLiteBaseActivity<DatabaseHelper> {// implements{
GridView gridview ;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.select_goal_background);
final String from = getIntent().getExtras().getString("from");
goalsList = new ArrayList<Goal>();
try {
goalsList = getTop3Goals();
} catch (SQLException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (java.sql.SQLException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
gridview = (GridView) findViewById(R.id.gridview);
gridview.setAdapter(new ImageAdapter(this));
gridview.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
ImageView l = (ImageView)gridview.getChildAt(position);
Drawable path= l.getDrawable();
Bitmap bitmap = ((BitmapDrawable)path).getBitmap();
Intent intent = new Intent(SelectGoalBackground.this, AlarmAppActivity.class);
intent.putExtra("Bitmap", bitmap);
startActivity(intent);
SelectGoalBackground.this.finish();
return;
});
}
public class ImageAdapter extends BaseAdapter {
private Context mContext;
public ImageAdapter(Context c) {
mContext = c;
}
public int getCount() {
return mThumbIds.length;
}
public Object getItem(int position) {
return null;
}
public long getItemId(int position) {
return 0;
}
// create a new ImageView for each item referenced by the Adapter
public View getView(int position, View convertView, ViewGroup parent) {
ImageView imageView;
if (convertView == null) { // if it's not recycled, initialize some attributes
imageView = new ImageView(mContext);
imageView.setLayoutParams(new GridView.LayoutParams(85, 85));
imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
imageView.setPadding(8, 8, 8, 8);
} else {
imageView = (ImageView) convertView;
}
Bitmap bm = BitmapFactory.decodeResource(getResources(), mThumbIds[position]);
imageView.setImageBitmap(bm);
return imageView;
}
// references to our images
private Integer[] mThumbIds = {
R.drawable.sample_0, R.drawable.sample_1
};
}
在调用活动时,我得到这样的位图
RelativeLayout rel_lay = (RelativeLayout) findViewById(R.id.main_lay);
Bitmap bitmap = (Bitmap)this.getIntent().getParcelableExtra("Bitmap");
if (bitmap != null) {
Log.v("bitmap", "not null");
Drawable drawable = new BitmapDrawable(getResources(), bitmap);
rel_lay.setBackgroundDrawable(drawable);
}
但这里的位图为空,并且没有设置此活动的背景。任何形式的帮助表示赞赏,请帮助