我有这个 Android 程序，我想在其中显示一个Rectangle父ImageView布局。组件设置在此层次结构上并遵循下面列出的布局。显示矩形的代码也如下所示：
- 线性布局 [垂直]
- 微调器
- 图像视图
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<Spinner
android:id="@+id/spinMap"
android:layout_width="match_parent"
android:layout_height="wrap_content"
tools:listitem="@android:layout/simple_spinner_item" />
<ImageView
android:id="@+id/imageMap"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@android:color/black" />
</LinearLayout>
代码：
public class MainActivty extends Activity {
private Display display;
private Spinner spinMap;
private ImageView imageMap;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initailize();
}
private void initailize() {
display = getWindowManager().getDefaultDisplay();
spinMap = (Spinner) findViewById(R.id.spinMap);
imageMap = (ImageView) findViewById(R.id.imageMap);
imageMap.draw(drawMap());
}
private Canvas drawMap() {
Canvas canvas = new Canvas(Bitmap.createBitmap(display.getWidth(), display.getHeight(), Bitmap.Config.RGB_565));
Paint paint = new Paint();
paint.setColor(Color.RED);
canvas.drawRect(10.0f, 10.0f, 100.0f, 100.0f, paint);
return canvas;
}
}
问题是当我运行应用程序时，Rectangle没有显示。我怎样才能显示Rectangle？