touch 事件首先返回子视图。如果您为它们定义 onClick 或 onTouch 侦听器,则父视图(例如片段)将不会收到任何触摸侦听器。所以如果你想在这种情况下为片段定义滑动监听器,你必须在一个新的类中实现它:
package com.neganet.QRelations.fragments;
import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.widget.FrameLayout;
public class SwipeListenerFragment extends FrameLayout {
private float x1,x2;
static final int MIN_DISTANCE=150;
private onSwipeEventDetected mSwipeDetectedListener;
public SwipeListenerFragment(Context context) {
super(context);
}
public SwipeListenerFragment(Context context, AttributeSet attrs) {
super(context, attrs);
}
public SwipeListenerFragment(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
boolean result=false;
switch(ev.getAction())
{
case MotionEvent.ACTION_DOWN:
x1 = ev.getX();
break;
case MotionEvent.ACTION_UP:
x2 = ev.getX();
float deltaX = x2 - x1;
if (Math.abs(deltaX) > MIN_DISTANCE)
{
if(deltaX<0)
{
result=true;
if(mSwipeDetectedListener!=null)
mSwipeDetectedListener.swipeLeftDetected();
}else if(deltaX>0){
result=true;
if(mSwipeDetectedListener!=null)
mSwipeDetectedListener.swipeRightDetected();
}
}
break;
}
return result;
}
public interface onSwipeEventDetected
{
public void swipeLeftDetected();
public void swipeRightDetected();
}
public void registerToSwipeEvents(onSwipeEventDetected listener)
{
this.mSwipeDetectedListener=listener;
}
}
您可以完全像这样为其他类型的布局制作工具。此类可以检测左右滑动,特别是在检测后返回 onInterceptTouchEvent true。这很重要,因为如果我们不这样做,有时子视图可能会收到事件,并且 Swipe for fragment 和 onClick for child view(例如)都会运行并导致一些问题。
制作完此类后,您必须更改片段 xml 文件:
<com.neganet.QRelations.fragments.SwipeListenerFragment xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:id="@+id/main_list_layout"
android:clickable="true"
android:focusable="true"
android:focusableInTouchMode="true"
android:layout_height="match_parent" tools:context="com.neganet.QRelations.fragments.mainList"
android:background="@color/main_frag_back">
<!-- TODO: Update blank fragment layout -->
<android.support.v7.widget.RecyclerView
android:id="@+id/farazList"
android:scrollbars="horizontal"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="left|center_vertical" />
</com.neganet.QRelations.fragments.SwipeListenerFragment>
你看到开始标签是我们创建的类。现在在片段类中:
View view=inflater.inflate(R.layout.fragment_main_list, container, false);
SwipeListenerFragment tdView=(SwipeListenerFragment) view;
tdView.registerToSwipeEvents(this);
and then Implement SwipeListenerFragment.onSwipeEventDetected in it:
@Override
public void swipeLeftDetected() {
Toast.makeText(getActivity(), "left", Toast.LENGTH_SHORT).show();
}
@Override
public void swipeRightDetected() {
Toast.makeText(getActivity(), "right", Toast.LENGTH_SHORT).show();
}
这有点复杂,但效果很好:)