事件传递、 手势GestureDetector

事件传递

Android的事件传递有下面三种方法：

1、dispatchTouchEvent 表示事件的分发

2、onInterceptTouchEvent 表示事件的拦截

3、onTouchEvent 表示事件的处理

返回值为false表示不拦截、不分发

下拉刷新：

package com.example.administrator.myrefreshdemo;

import android.animation.ObjectAnimator;
import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.FrameLayout;
import android.widget.ListView;

/**
* Created by Administrator on 2015/9/24.
*/
public class MyRefreshLayout extends FrameLayout {
ListView content;

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

public MyRefreshLayout(Context context, AttributeSet attrs) {
super(context, attrs);
//先添加一个下拉刷新
LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View header = inflater.inflate(R.layout.activity_fresh,null);
addView(header);
//再添加一个上边的view
content = (ListView) inflater.inflate(R.layout.activity_listview,null);
addView(content);

ArrayAdapter <String> adapter = new ArrayAdapter<String>(context,android.R.layout.simple_list_item_1,new String[]{"a","b","c","d","e","f","a","b","c","d","e","f"});
content.setAdapter(adapter);
}

public MyRefreshLayout(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}

@Override
public boolean dispatchTouchEvent(MotionEvent ev) {
return super.dispatchTouchEvent(ev);
}

@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
if (ev.getAction() == MotionEvent.ACTION_DOWN){
Log.d("mytouch","linearlayoutonInterceptTouchEvent"+ev.getAction()+super.onInterceptTouchEvent(ev));
}
if (content.getFirstVisiblePosition() == 0){
View firstView = content.getChildAt(content.getFirstVisiblePosition());
if (firstView.getY() >=0){
Log.d("mytouch","拦截到事件");
return true;
}
}
return super.onInterceptTouchEvent(ev);
}
float y = 0;
float oldY = 0;
@Override
public boolean onTouchEvent(MotionEvent event) {
switch (event.getAction()){
case MotionEvent.ACTION_DOWN:
oldY = event.getY();
break;
case MotionEvent.ACTION_MOVE:
Log.d("mytouch","处理事件");
y = event.getY();
float distance = y - oldY;
content.setTranslationY(content.getTranslationY()+distance);
oldY = y;
break;
case MotionEvent.ACTION_UP:
ObjectAnimator.ofFloat(content,"translationY",content.getTranslationY(),0).setDuration(300).start();
break;
}
return true;
}
}

布局文件

<com.example.administrator.myrefreshdemo.MyRefreshLayout
android:layout_width="match_parent"
android:layout_height="match_parent">

</com.example.administrator.myrefreshdemo.MyRefreshLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="@+id/refresh"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="下拉刷新"
android:textSize="20dp"
android:gravity="center"
android:padding="10dp"/>

</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<ListView xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#ffffff">

</ListView>

谷歌自己写的下拉刷新,用时需要support.v4包

public class MainActivity extends Activity {
private SwipeRefreshLayout mSwipeRefreshLayout;
private ListView mListView;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mSwipeRefreshLayout = (SwipeRefreshLayout) findViewById(R.id.swiperefreshlayout);
mListView = (ListView) findViewById(R.id.listview);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,new String[]{"a","b","c","d","e","f","a","b","c","d","e","f"});
mListView.setAdapter(adapter);
mSwipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener(){
@Override
public void onRefresh() {
mSwipeRefreshLayout.setRefreshing(false);
}
});
}
}

布局文件

<android.support.v4.widget.SwipeRefreshLayout
android:id="@+id/swiperefreshlayout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ListView
android:id="@+id/listview"
android:layout_width="match_parent"
android:layout_height="match_parent"></ListView>

</android.support.v4.widget.SwipeRefreshLayout>

手势

双击、滑动、按住移动

package com.example.administrator.myrefreshdemo;

import android.animation.ObjectAnimator;
import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.View;
import android.widget.Button;

import java.util.Objects;

/**
* Created by Administrator on 2015/9/24.
*/
public class MyButton extends Button {
private GestureDetector mGesture;

//监听者模式
interface onDoubleClick{
public void onDoubleClick(View view);
}
private onDoubleClick onDoubleClickListener;

public void setOnDoubleClickListener(onDoubleClick onDoubleClickListener) {
this.onDoubleClickListener = onDoubleClickListener;
}

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

public MyButton(Context context, AttributeSet attrs) {
super(context, attrs);
mGesture = new GestureDetector(context,new GestureDetector.SimpleOnGestureListener(){
//双击按钮
@Override
public boolean onDoubleTap(MotionEvent e) {
if (onDoubleClickListener!=null){
onDoubleClickListener.onDoubleClick(MyButton.this);
}
Log.d("mydoubletap","连续点击两次");
return true;

}

//划一下，手离开屏幕后移动
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
if (Math.abs(e2.getX()-e1.getX())>50){
Log.d("mydoubletap", "在X轴滑动");
//                    setTranslationX(e2.getX() - e1.getX());
ObjectAnimator.ofFloat(MyButton.this,"translationX",getTranslationX(),e2.getX() - e1.getX()).setDuration(800).start();
return true;
}
return super.onFling(e1, e2, velocityX, velocityY);
}

//随着手指在屏幕上move而move
@Override
public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
setTranslationX(getTranslationX()+e2.getX() - e1.getX());
setTranslationY(getTranslationY()+e2.getY() - e1.getY());
return true;
}
});
}

public MyButton(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}

@Override
public boolean dispatchTouchEvent(MotionEvent event) {
return super.dispatchTouchEvent(event);
}

@Override
public boolean onTouchEvent(MotionEvent event) {
mGesture.onTouchEvent(event);
return super.onTouchEvent(event);
}
}

public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

MyButton button = (MyButton) findViewById(R.id.mybutton);
button.setOnDoubleClickListener(new MyButton.onDoubleClick() {
@Override
public void onDoubleClick(View view) {
Toast.makeText(getApplicationContext(),"双击两次",Toast.LENGTH_SHORT).show();
}
});
}
}