onInterceptTouchEvent只得到ACTION

onInterceptTouchEvent只得到ACTION

本文介绍了onInterceptTouchEvent只得到ACTION_DOWN的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!

问题描述

为什么ViewGroup中唯一获得ACTION_DOWN在onInterceptTouchEvent?根据文档,只要返回false应接收所有的事件类型。http://developer.android.com/reference/android/view/ViewGroup.html#onInterceptTouchEvent%28android.view.MotionEvent%29点#3。

样品code:

 公共类MainActivity延伸活动{

私有静态最后字符串变量= MainActivity.class.getSimpleName();

@覆盖
保护无效的onCreate(包savedInstanceState){
    super.onCreate(savedInstanceState);
    的setContentView(新容器(本));
}

私有类容器扩展的LinearLayout {

    公共集装箱(上下文的背景下){
        超(上下文);
        setBackgroundColor(0xFF0000FF);
    }

    @覆盖
    公共布尔onInterceptTouchEvent(MotionEvent EV){
        Log.i(TAG,onInterceptTouchEvent);
        INT行动= ev.getActionMasked();
        开关(动作){
        案例MotionEvent.ACTION_DOWN:
            Log.i(TAG,onInterceptTouchEvent.ACTION_DOWN);
            打破;
        案例MotionEvent.ACTION_MOVE:
            Log.i(TAG,onInterceptTouchEvent.ACTION_MOVE);
            打破;
        案例MotionEvent.ACTION_CANCEL:
        案例MotionEvent.ACTION_UP:
            Log.i(TAG,onInterceptTouchEvent.ACTION_UP);
            打破;
    }
        返回super.onInterceptTouchEvent(EV);
    }

}
}
 

解决方案

我会回答我的问题:onInterceptTouchEvent只被调用,如果父母有从的onTouchEvent返回true子视图。一旦孩子返回true,家长现在有机会截获该事件。

Why do ViewGroup's only get ACTION_DOWN in the onInterceptTouchEvent? According to the docs, as long as false is returned it should receive all the event types.http://developer.android.com/reference/android/view/ViewGroup.html#onInterceptTouchEvent%28android.view.MotionEvent%29Point #3.

sample code:

public class MainActivity extends Activity {

private static final String TAG = MainActivity.class.getSimpleName();

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(new Container(this));
}

private class Container extends LinearLayout {

    public Container(Context context) {
        super(context);
        setBackgroundColor(0xFF0000FF);
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        Log.i(TAG, "onInterceptTouchEvent");
        int action = ev.getActionMasked();
        switch (action) {
        case MotionEvent.ACTION_DOWN:
            Log.i(TAG, "onInterceptTouchEvent.ACTION_DOWN");
            break;
        case MotionEvent.ACTION_MOVE:
            Log.i(TAG, "onInterceptTouchEvent.ACTION_MOVE");
            break;
        case MotionEvent.ACTION_CANCEL:
        case MotionEvent.ACTION_UP:
            Log.i(TAG, "onInterceptTouchEvent.ACTION_UP");
            break;
    }
        return super.onInterceptTouchEvent(ev);
    }

}
}
解决方案

I'll answer my own question: onInterceptTouchEvent only get called if the parent has a child view which returns "true" from onTouchEvent. Once the child returns true, the parent now has a chance to intercept that event.

这篇关于onInterceptTouchEvent只得到ACTION_DOWN的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!

07-26 08:46