基于ListView的滑动删除、添加、修改

在很多App应用当中我们都看见过各式各样的listview，当然，我们自己对于这个控件肯定也是相当熟悉，那么为什么要在listview中嵌套进一个侧滑删除等这些细节性的功能呢？

其实原因很简单，就是用户体验！试想一下当一个界面中展示给用户得信息过多，而这些信息又并不是特别重要的，那么用户为了方便肯定有这个需求了，而这个方便在我们看来就是需求。接下来看看这个“方便”是怎么达到效果的

activity_main.xml布局文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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:clickable="true"
android:orientation="vertical"
tools:context="com.example.administrator.testpopuwindow.MainActivity"
>

<ListView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/listView" />

</LinearLayout>

listview_adapter.xml文件

<?xml version="1.0" encoding="utf-8"?>
<HorizontalScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/hsv"
android:layout_width="wrap_content"
android:layout_height="80dip"
android:scrollbars="none" >

<LinearLayout
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:orientation="horizontal" >

<LinearLayout
android:id="@+id/ll_content"
android:layout_width="match_parent"
android:layout_height="match_parent"
>

<TextView
android:id="@+id/tv"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:text="" />
</LinearLayout>

<LinearLayout
android:id="@+id/ll_action"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal" >

<Button
android:id="@+id/button1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
android:background="@android:color/darker_gray"
android:paddingLeft="20dip"
android:paddingRight="20dip"
android:text="添加" />

<Button
android:id="@+id/button2"
android:layout_weight="1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginLeft="2dip"
android:layout_marginRight="2dip"
android:background="@android:color/darker_gray"
android:paddingLeft="20dip"
android:paddingRight="20dip"
android:text="删除" />

<Button
android:id="@+id/button3"
android:layout_weight="1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@android:color/darker_gray"
android:paddingLeft="20dip"
android:paddingRight="20dip"
android:text="变色" />
</LinearLayout>
</LinearLayout>

</HorizontalScrollView>

MainActivity

package com.example.administrator.testpopuwindow;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.DisplayMetrics;
import android.view.View;
import android.widget.ListView;

public class MainActivity extends AppCompatActivity {
private ListView listView;

@Override
protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Instantiation();

}

public void Instantiation(){

listView = (ListView) findViewById(R.id.listView);
DisplayMetrics dm = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(dm);
AdapterTest adapterTest = new AdapterTest(this,dm.widthPixels);
listView.setAdapter(adapterTest);

}

}

AdapterTest 适配器

package com.example.administrator.testpopuwindow;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewGroup.LayoutParams;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.HorizontalScrollView;
import android.widget.TextView;

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

/**
* Created by Administrator on 2016-05-12.
*/
public class AdapterTest extends BaseAdapter implements View.OnClickListener {

// 数据源，用于存放颜色值的。
private List<Integer> colors;
private Context mContext;
// 屏幕宽度,由于我们用的是HorizontalScrollView,所以按钮选项应该在屏幕外
private int mScreentWidth;
private View view;

/**
* 构造方法
*
* @param context
* @param screenWidth
*/
public AdapterTest(Context context, int screenWidth) {

// 初始化
mContext = context;
mScreentWidth = screenWidth;

// 填充list的内容模拟数据，否则应该异步执行
colors = new ArrayList<Integer>();
for (int i = 0; i < 15; i++) {
colors.add(R.color.zise);
}
}

@Override
public int getCount() {

return colors.size();

}

@Override
public Object getItem(int position) {

return colors.get(position);

}

@Override
public long getItemId(int position) {

return position;

}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
// 如果没有设置过,初始化convertView
if (convertView == null) {
// 获得设置的view
convertView = LayoutInflater.from(mContext).inflate(R.layout.listview_adapter, parent, false);

// 初始化holder
holder = new ViewHolder();
holder.hSView = (HorizontalScrollView) convertView.findViewById(R.id.hsv);

holder.action = convertView.findViewById(R.id.ll_action);
holder.btOne = (Button) convertView.findViewById(R.id.button1);
holder.btTwo = (Button) convertView.findViewById(R.id.button2);
holder.btThree = (Button) convertView.findViewById(R.id.button3);
holder.tvContent = (TextView) convertView.findViewById(R.id.tv);

// 设置内容view的大小为屏幕宽度,这样按钮就正好被挤出屏幕外
holder.content = convertView.findViewById(R.id.ll_content);
LayoutParams lp = holder.content.getLayoutParams();
lp.width = mScreentWidth;

convertView.setTag(holder);
} else {
// 有直接获得ViewHolder
holder = (ViewHolder) convertView.getTag();
}
// 把位置放到view中,这样点击事件就可以知道点击的是哪一条item
holder.btOne.setTag(position);
holder.btTwo.setTag(position);
holder.btThree.setTag(position);

// 设置监听事件
convertView.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {

switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
if (view != null) {
ViewHolder viewHolder1 = (ViewHolder) view.getTag();
viewHolder1.hSView.smoothScrollTo(0, 0);
}
case MotionEvent.ACTION_UP:
// 获得ViewHolder
ViewHolder viewHolder = (ViewHolder) v.getTag();
view = v;
// 获得HorizontalScrollView滑动的水平方向值.
int scrollX = viewHolder.hSView.getScrollX();

// 获得操作区域的长度
int actionW = viewHolder.action.getWidth();

// 注意使用smoothScrollTo,这样效果看起来比较圆滑,不生硬
// 如果水平方向的移动值<操作区域的长度的一半,就复原
if (scrollX < actionW / 2) {

viewHolder.hSView.smoothScrollTo(0, 0);

}
else{// 否则的话显示操作区域

viewHolder.hSView.smoothScrollTo(actionW, 0);

}
return true;
}
return false;
}
});

// 这里防止删除一条item后,ListView处于操作状态,直接还原
if (holder.hSView.getScrollX() != 0) {
holder.hSView.scrollTo(0, 0);
}

// 设置背景颜色,设置填充内容.
holder.content.setBackgroundResource(colors.get(position));
holder.tvContent.setText("" + position);

// 设置监听事件
holder.btOne.setOnClickListener(this);
holder.btTwo.setOnClickListener(this);
holder.btThree.setOnClickListener(this);

return convertView;
}

/**
* ViewHolder
*
* @Title:
* @Description:主要是避免了不断的view获取初始化.
*/
class ViewHolder {
public HorizontalScrollView hSView;

public View content;
public TextView tvContent;

public View action;
public Button btOne;
public Button btTwo;
public Button btThree;
}

@Override
public void onClick(View v) {
int position = (Integer) v.getTag();
switch (v.getId()) {
case R.id.button1:
colors.add(R.color.zise);
break;
case R.id.button2:
colors.remove(position);
break;
case R.id.button3:
if (colors.get(position) == R.color.zise) {
colors.set(position, R.color.huang);
} else {
colors.set(position, R.color.zise);
}
break;

default:
break;
}
// 刷新ListView内容
notifyDataSetChanged();
}
}

OK! listview侧滑功能就实现了(原理：HorizontalScrollView嵌套ListView).