android滑动删除的多种实现方式(一)

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个人习惯，先上图

同事是个妹子(这点很重要)，写滑动删除动能的时候用到了SwipeLayout,然后悲催的是，滑动时间被拦截了，解决方法先不提，在(一)中先讲解SwipeLayout下载listview并实现滑动删除效果，当然加载listview有很多种方式，后面都会讲到，

首先你需要了解ViewDragHelper，ViewDragHelper重写触摸事件参数从而可以拖动改变子view的位置，具体魅力见：

需要看源码的关联一下http://www.tuicool.com/articles/JZbEvya

2013年谷歌i/o大会上介绍了两个新的layout： SlidingPaneLayout和DrawerLayout都用到viewdragHelper处理拖动事件，好了话不多费能力有限精力不充足不研究太深，会用就ok，具体见滑动删除例子代码：

》》》创建SwipeLayout

package com.one.swipe;

import android.content.Context;
import android.graphics.Rect;
import android.support.v4.view.ViewCompat;
import android.support.v4.widget.ViewDragHelper;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.widget.FrameLayout;

/**
* 相当于继承viewGroup
*/
public class SwipeLayout extends FrameLayout {

/**
* 用到枚举三种状态，代码模式
*/
public static enum Status {
Close, Open, Swiping
}

public interface OnSwipeListener{
void onClose(SwipeLayout layout);
void onOpen(SwipeLayout layout);

void onStartOpen(SwipeLayout layout);
void onStartClose(SwipeLayout layout);
}

private Status status = Status.Close;
private OnSwipeListener onSwipeListener;

public Status getStatus() {
return status;
}

public void setStatus(Status status) {
this.status = status;
}

public OnSwipeListener getOnSwipeListener() {
return onSwipeListener;
}

public void setOnSwipeListener(OnSwipeListener onSwipeListener) {
this.onSwipeListener = onSwipeListener;
}

//--------------------------上面和我们常用设置adapter差不多绑定侦听和布局设置参数
private ViewDragHelper mHelper;

public SwipeLayout(Context context) {
this(context, null);
}

public SwipeLayout(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}

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

// 1. 创建ViewDragHelper 第二个参数默认值
mHelper = ViewDragHelper.create(this,1.0f, callback);
}

// 3. 重写一系列回调的方法
ViewDragHelper.Callback callback = new ViewDragHelper.Callback() {

@Override
public boolean tryCaptureView(View child, int pointerId) {
return true;
}

/**
* 水平方向移动的处理限制范围
*/
public int getViewHorizontalDragRange(View child) {
return mRange;
};
/**
* 竖直方向的处理
*/
public int clampViewPositionHorizontal(View child, int left, int dx) {
// 返回的值决定了将要移动到的位置.
if(child == mFrontView){
if(left < - mRange){
// 限定左范围
return - mRange;
}else if (left > 0) {
// 限定右范围
return 0;
}
}else if (child == mBackView) {
if(left < mWidth - mRange){
// 限定左范围
return mWidth - mRange;
}else if (left > mWidth) {
// 限定右范围
return mWidth;
}
}
return left;
};

// 位置发生改变的时候, 把水平方向的偏移量传递给另一个布局
public void onViewPositionChanged(View changedView, int left, int top, int dx, int dy) {
if(changedView == mFrontView){
// 拖拽的是前布局, 把刚刚发生的偏移量dx 传递给后布局
mBackView.offsetLeftAndRight(dx);
} else if (changedView == mBackView) {
// 拖拽的是后布局, 把刚刚发生的偏移量dx 传递给前布局
mFrontView.offsetLeftAndRight(dx);
}

dispatchDragEvent();

invalidate();
};
/**
* Released svn上貌似有这个设置，回滚
*/
public void onViewReleased(View releasedChild, float xvel, float yvel) {
// 松手时候会被调用
// xvel 向右+, 向左-
if(xvel == 0 && mFrontView.getLeft() < - mRange * 0.5f){
open();
}else if(xvel < 0){
open();
}else {
close();
}
};
};
private View mBackView;
private View mFrontView;
private int mRange;
private int mWidth;
private int mHeight;

/**
* 更新当前的状态
*/
protected void dispatchDragEvent() {

Status lastStatus = status;
// 获取最新的状态
status = updateStatus();

// 状态改变的时候, 调用监听里的方法
if(lastStatus != status && onSwipeListener != null){
if(status == Status.Open){
onSwipeListener.onOpen(this);
}else if (status == Status.Close) {
onSwipeListener.onClose(this);
}else if (status == Status.Swiping) {
if(lastStatus == Status.Close){
onSwipeListener.onStartOpen(this);
}else if (lastStatus == Status.Open) {
onSwipeListener.onStartClose(this);
}
}
}

}

private Status updateStatus() {
int left = mFrontView.getLeft();
if(left == 0){
return Status.Close;
}else if (left == -mRange) {
return Status.Open;
}

return Status.Swiping;
}

@Override
public void computeScroll() {
super.computeScroll();
// 维持平滑动画继续
if(mHelper.continueSettling(true)){
ViewCompat.postInvalidateOnAnimation(this);
}
}

/**
* 关闭
*/
protected void close() {
close(true);
}
public void close(boolean isSmooth){

int finalLeft = 0;
if(isSmooth){
// 触发平滑动画
if(mHelper.smoothSlideViewTo(mFrontView, finalLeft, 0)){
ViewCompat.postInvalidateOnAnimation(this);
}

}else {
layoutContent(false);
}
}

/**
* 打开
*/
protected void open() {
open(true);
}
public void open(boolean isSmooth){

int finalLeft = -mRange;
if(isSmooth){
// 触发平滑动画
if(mHelper.smoothSlideViewTo(mFrontView, finalLeft, 0)){
ViewCompat.postInvalidateOnAnimation(this);
}

}else {
layoutContent(false);
}
}
// 2. 转交触摸事件拦截判断, 处理触摸事件
public boolean onInterceptTouchEvent(android.view.MotionEvent ev) {
if (mHelper.shouldInterceptTouchEvent(ev)) {
return true;
}
return super.onInterceptTouchEvent(ev);
};
/**
* 时间交由mHelper处理，默认返回true
*/
@Override
public boolean onTouchEvent(MotionEvent event) {

try {
mHelper.processTouchEvent(event);
} catch (Exception e) {
e.printStackTrace();
}

return true;
}

@Override
protected void onLayout(boolean changed, int left, int top, int right,
int bottom) {
super.onLayout(changed, left, top, right, bottom);

// 默认是关闭状态
layoutContent(false);
}

/**
* 根据当前的开启状态摆放内容
* @param isOpen
*/
private void layoutContent(boolean isOpen) {
// 设置前布局位置
Rect rect = computeFrontRect(isOpen);
mFrontView.layout(rect.left, rect.top, rect.right, rect.bottom);
// 根据前布局位置设置后布局位置
Rect backRect = computeBackRectViaFront(rect);
mBackView.layout(backRect.left, backRect.top, backRect.right, backRect.bottom);

// 把任意布局顺序调整到最上
bringChildToFront(mFrontView);
}

/**
* 计算后布局的矩形区域
* @param rect
* @return
*/
private Rect computeBackRectViaFront(Rect rect) {
int left = rect.right;
return new Rect(left, 0, left + mRange , 0 + mHeight);
}

/**
* 计算前布局的矩形区域
* @param isOpen
* @return
*/
private Rect computeFrontRect(boolean isOpen) {
int left = 0;
if(isOpen){
left = -mRange;
}
return new Rect(left, 0, left + mWidth, 0 + mHeight);
}

@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);

mRange = mBackView.getMeasuredWidth();
mWidth = getMeasuredWidth();
mHeight = getMeasuredHeight();

}
/**
* 赋值等一些操作
*/
@Override
protected void onFinishInflate() {
super.onFinishInflate();

mBackView = getChildAt(0);
mFrontView = getChildAt(1);
}

/**
* 这个方法可以用来设置拖动距离等操作
*/
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// TODO Auto-generated method stub
super.onMeasure(widthMeasureSpec, heightMeasureSpec);

}

============================================================

package com.one.swipe;

import java.util.ArrayList;
import java.util.List;

import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

import com.one.swipe.SwipeLayout.OnSwipeListener;

public class MyAdapter extends BaseAdapter {
private Context context;
private List<String> list;
private ArrayList<SwipeLayout> openedItems;

public MyAdapter(Context context, List<String> list) {
super();
this.context=context;
this.list=list;
openedItems = new ArrayList<SwipeLayout>();
}
@Override
public int getCount() {
return list==null?0:list.size();
}

@Override
public Object getItem(int position) {
return list == null ? 0 : position;
}

@Override
public long getItemId(int position) {
return 0;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if(convertView==null){
holder = new ViewHolder();
convertView=View.inflate(context, R.layout.public_type_item, null);
holder.tv_type=(TextView) convertView.findViewById(R.id.tv_type);
holder.tv_date=(TextView) convertView.findViewById(R.id.tv_date);
holder.tv_price=(TextView) convertView.findViewById(R.id.tv_price);
convertView.setTag(holder);
}else{
holder=(ViewHolder) convertView.getTag();
}
SwipeLayout sl = (SwipeLayout)convertView;

sl.setOnSwipeListener(new OnSwipeListener() {

@Override
public void onClose(SwipeLayout layout) {
openedItems.remove(layout);
}

@Override
public void onOpen(SwipeLayout layout) {
openedItems.add(layout);
}

@Override
public void onStartOpen(SwipeLayout layout) {
// 关闭所有已经打开的条目
for (int i = 0; i < openedItems.size(); i++) {
openedItems.get(i).close(true);
}

openedItems.clear();
}

@Override
public void onStartClose(SwipeLayout layout) {
}

});

String tv_type=holder.tv_type.getText().toString().trim();
List<String> list = new ArrayList<String>();
list.add(tv_type);
return convertView;
}
class ViewHolder{
public TextView tv_type;
public TextView tv_date;
public TextView tv_price;
}

}

====================================

MainActivity

package com.one.swipe;

import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;

public class MainActivity extends Activity implements OnClickListener {

private Button btn;
private ListView view;
private List<String> list;
private MyAdapter adapter;
private EditText et;

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

btn = (Button) findViewById(R.id.btn);
btn.setOnClickListener(this);
view = (ListView) findViewById(R.id.listview);
et = (EditText) findViewById(R.id.et);

initData();
}

private void initData() {
list = new ArrayList();
for (int i = 0; i < 3; i++) {
list.add(i + "");
}

}

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
switch (v.getId()) {
case R.id.btn:

adapter = new MyAdapter(getApplicationContext(), list);
view.setAdapter(adapter);
adapter.notifyDataSetChanged();

break;

default:
break;
}
}

}

================================

main.xml

<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scrollbars="vertical" >

</LinearLayout>
</ScrollView>

============================

item.xml

<?xml version="1.0" encoding="utf-8"?>
<com.one.swipe.SwipeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/sl"
android:layout_width="match_parent"
android:layout_height="@dimen/item_height" >
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="@dimen/item_height"
android:orientation="horizontal" >