Android中onTouch，onTouchEvent，onClick优先级，关系

Android中onTouch，onTouchEvent，onClick优先级，关系

1.基础介绍

onTouch:指的是View设置的OnTouchListener接口的onTouch（）方法

onTouchEvent：指的是事件分发中的重要方法（dispatchTouchEvent，onInterceptTouchEvent，onTouchEvent）

onClick：指的是View设置的OnClickListener接口的onClick（）方法

2.源码分析

首先看一下View的dispatchTouchEvent方法（删掉了多余的代码）

public boolean dispatchTouchEvent(MotionEvent event) {
    boolean result = false;
    
    if (onFilterTouchEventForSecurity(event)) {
        //noinspection SimplifiableIfStatement
        ListenerInfo li = mListenerInfo;
        if (li != null && li.mOnTouchListener != null
                && (mViewFlags & ENABLED_MASK) == ENABLED
                && li.mOnTouchListener.onTouch(this, event)) {
            result = true;
        }

        if (!result && onTouchEvent(event)) {
            result = true;
        }
    }

    return result;
}

其中mOnTouchListener指的就是我们通过 setOnTouchListener（）设置的接口，可以知道如果onTouch（）返回true的话，事件就被消化，onTouchEvent（）就不会收到事件了，所以onTouch比onTouchEvent优先级高

接着看一下onTouchEvent（）

public boolean onTouchEvent(MotionEvent event) {
    final float x = event.getX();
    final float y = event.getY();
    final int viewFlags = mViewFlags;
    final int action = event.getAction();

    
   
    if (((viewFlags & CLICKABLE) == CLICKABLE ||
            (viewFlags & LONG_CLICKABLE) == LONG_CLICKABLE) ||
            (viewFlags & CONTEXT_CLICKABLE) == CONTEXT_CLICKABLE) {
        switch (action) {
            case MotionEvent.ACTION_UP:
                boolean prepressed = (mPrivateFlags & PFLAG_PREPRESSED) != 0;
                if ((mPrivateFlags & PFLAG_PRESSED) != 0 || prepressed) {
                    // take focus if we don't have it already and we should in
                    // touch mode.
            
                    if (!mHasPerformedLongPress && !mIgnoreNextUpEvent) {
                        // This is a tap, so remove the longpress check
                        removeLongPressCallback();

                        // Only perform take click actions if we were in the pressed state
                        if (!focusTaken) {
                            // Use a Runnable and post this rather than calling
                            // performClick directly. This lets other visual state
                            // of the view update before click actions start.
                            if (mPerformClick == null) {
                                mPerformClick = new PerformClick();
                            }
                            if (!post(mPerformClick)) {
                                performClick();
                            }
                        }
                    }
                
                }
                mIgnoreNextUpEvent = false;
                break;

        }

        return true;
    }

    return false;
}

接着看看performClick（）

public boolean performClick() {
    final boolean result;
    final ListenerInfo li = mListenerInfo;
    if (li != null && li.mOnClickListener != null) {
        playSoundEffect(SoundEffectConstants.CLICK);
        li.mOnClickListener.onClick(this);
        result = true;
    } else {
        result = false;
    }

    sendAccessibilityEvent(AccessibilityEvent.TYPE_VIEW_CLICKED);
    return result;
}

从中可以看出在onTouchEvent（）中，调用了我们设置的OnClickListener()接口中的onClick（），所以onTouchEvent优先级高于onClick

总结

优先级从高到低：onTouch>onTouchEvent>onClick