小记DrawerLayout点击事件传递

今天遇到的问题是DrawerLayout在上面，下面的View拿不到点击事件，最后实在没办法，都曲线救国了（只要解决需求，曲线救国也是不错的选择），挽起袖子撸完代码，对曲线救国的效果也比较满意，坐下来没事了就想看看不能解决点击的冲突，就进到DrawerLayout源码里看了一下，发现了这一段

<pre>
@Override
public boolean onTouchEvent(MotionEvent ev) {
mLeftDragger.processTouchEvent(ev);
mRightDragger.processTouchEvent(ev);

    final int action = ev.getAction();
    boolean wantTouchEvents = true;

    switch (action & MotionEventCompat.ACTION_MASK) {
        case MotionEvent.ACTION_DOWN: {
            final float x = ev.getX();
            final float y = ev.getY();
            mInitialMotionX = x;
            mInitialMotionY = y;
            mDisallowInterceptRequested = false;
            mChildrenCanceledTouch = false;
            break;
        }

        case MotionEvent.ACTION_UP: {
            final float x = ev.getX();
            final float y = ev.getY();
            boolean peekingOnly = true;
            final View touchedView = mLeftDragger.findTopChildUnder((int) x, (int) y);
            if (touchedView != null && isContentView(touchedView)) {
                final float dx = x - mInitialMotionX;
                final float dy = y - mInitialMotionY;
                final int slop = mLeftDragger.getTouchSlop();
                if (dx * dx + dy * dy < slop * slop) {
                    // Taps close a dimmed open drawer but only if it isn't locked open.
                    final View openDrawer = findOpenDrawer();
                    if (openDrawer != null) {
                        peekingOnly = getDrawerLockMode(openDrawer) == LOCK_MODE_LOCKED_OPEN;
                    }
                }
            }
            closeDrawers(peekingOnly);
            mDisallowInterceptRequested = false;
            break;
        }

        case MotionEvent.ACTION_CANCEL: {
            closeDrawers(true);
            mDisallowInterceptRequested = false;
            mChildrenCanceledTouch = false;
            break;
        }
    }

    return wantTouchEvents;
}

</pre>
对，你没看错，他不但拦截了点击事件，还消费了，就说为什么传不下去，既然知道了问题的所在，解决起来就简单多了，我们可以自定义一个DrawerLayout，代码如下，其实很简单就是我们自己来控制DrawerLayout是否相应点击事件，（DrawerLayout为了响应抽屉的打开和收起，所以拦截了点击事件，当初没想起来）
<pre>
/**

• Created by Bert on 2017/7/26.
  */

public class MyDrawerLayout extends DrawerLayout {

private static final String TAG = "MyDrawerLayout";
private boolean is_click = true;

public MyDrawerLayout(Context context) {
    super(context);
}

public MyDrawerLayout(Context context, AttributeSet attrs) {
    super(context, attrs);
}

public MyDrawerLayout(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
}


/**
 * 控制DrawerLayout是否响应点击事件
 * @param can
 */
public void setCanClick(boolean can){
    is_click = can;
}


@Override
public boolean onTouchEvent(MotionEvent ev) {
    if(is_click){
        return super.onTouchEvent(ev);
    }else {
        return false;
    }

}

}
</pre>

OK,就这么简单，需要点击事件传递下去的时候setCanClick（false）就Ok了。

总结一下：还是看源码重要！！！！！！！！！