java - 从附加的 OnPreDrawListener 对象中获取 ViewTreeObserver 对象

Question

如何让观察者进入监听者？示例:

ViewTreeObserver myObserver = myLayout.getViewTreeObserver();
myObserver.addOnPreDrawListener(new OnPreDrawListener() {
    @Override
    public boolean onPreDraw() {
        // I want to get the myLayout or myObserver here, 
        // but I don't want to use the lines below
        RelativeLayout myLayout = (RelativeLayout)findViewById(myId);
        myLayout.getViewTreeObserver().removeOnPreDrawListener(this);

Answer 1

我试过玩听众实例，我不知道它有多准确，但它有效:)

final class MyOnPreDrawListener implements OnPreDrawListener
{
    private RelativeLayout myLayout;

    public void setMyLayout(RelativeLayout layout){
        myLayout = layout;
    }

    @Override
    public boolean onPreDraw() {
        // now I have myLayout here         
        return true;
    }

}

然后我打电话

ViewTreeObserver observer = myLayout.getViewTreeObserver();
MyOnPreDrawListener myListener = new MyOnPreDrawListener();
myListener.setMyLayout(myLayout);
observer.addOnPreDrawListener(myListener);