嗨,我试着编写一个截图的功能.
我找到了一个代码,通过按钮clicklistner完美地完成它,但当我删除按钮clicklistner并尝试在oncreate中截取我获得的位图是空的.
为什么会这样？

布局：

@H_502_12@
活动：

public class MainActivity extends Activity {
    LinearLayout L1;
    ImageView image;

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


        L1 = (LinearLayout) findViewById(R.id.LinearLayout01);
        Button but = (Button) findViewById(R.id.munchscreen);
        but.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                View v1 = L1.getRootView();
                v1.setDrawingCacheEnabled(true);
                Bitmap bm = v1.getDrawingCache();
                BitmapDrawable bitmapDrawable = new BitmapDrawable(bm);
                image = (ImageView) findViewById(R.id.screenshots);
                image.setBackgroundDrawable(bitmapDrawable);
            }
        });

    }


}
@H_502_12@