本来准备在listview的每个item的布局上设置一个隐藏的button，当滑动的时候显示。但是因为每次只要存在一个button，发现每个item上的button相互间不好控制。所以决定继承listview然后结合popupwindow。
首先是布局文件：
delete_btn.xml：这里只需要一个button
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<?xml version="1.0" encoding="utf-8"?>
<linearlayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical" >
<button
android:id="@+id/id_item_btn"
android:layout_width="60dp"
android:singleline="true"
android:layout_height="wrap_content"
android:text="删除"
android:background="@drawable/d_delete_btn"
android:textcolor="#ffffff"
android:paddingleft="15dp"
android:paddingright="15dp"
android:layout_alignparentright="true"
android:layout_centervertical="true"
android:layout_marginright="15dp"
/>
</linearlayout>
主布局文件：activity_main.xml，listview的每个item的样式直接使用了系统的android.r.layout.simple_list_item_1
<relativelayout 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" >
<com.example.listviewitemslidedeletebtnshow.qqlistview
android:id="@+id/id_listview"
android:layout_width="fill_parent"
android:layout_height="wrap_content" >
</com.example.listviewitemslidedeletebtnshow.qqlistview>
</relativelayout>
接下来看看qqlistview的实现：
package com.example.listviewitemslidedeletebtnshow;
import android.content.context;
import android.util.attributeset;
import android.view.gravity;
import android.view.layoutinflater;
import android.view.motionevent;
import android.view.view;
import android.view.viewconfiguration;
import android.widget.button;
import android.widget.linearlayout;
import android.widget.listview;
import android.widget.popupwindow;
public class qqlistview extends listview
{
private static final string tag = "qqlistview";
// private static final int velocity_sanp = 200;
// private velocitytracker mvelocitytracker;
/**
* 用户滑动的最小距离
*/
private int touchslop;
/**
* 是否响应滑动
*/
private boolean issliding;
/**
* 手指按下时的x坐标
*/
private int xdown;
/**
* 手指按下时的y坐标
*/
private int ydown;
/**
* 手指移动时的x坐标
*/
private int xmove;
/**
* 手指移动时的y坐标
*/
private int ymove;
private layoutinflater minflater;
private popupwindow mpopupwindow;
private int mpopupwindowheight;
private int mpopupwindowwidth;
private button mdelbtn;
/**
* 为删除按钮提供一个回调接口
*/
private delbuttonclicklistener mlistener;
/**
* 当前手指触摸的view
*/
private view mcurrentview;
/**
* 当前手指触摸的位置
*/
private int mcurrentviewpos;
/**
* 必要的一些初始化
*
* @param context
* @param attrs
*/
public qqlistview(context context, attributeset attrs)
{
super(context, attrs);
minflater = layoutinflater.from(context);
touchslop = viewconfiguration.get(context).getscaledtouchslop();
view view = minflater.inflate(r.layout.delete_btn, null);
mdelbtn = (button) view.findviewbyid(r.id.id_item_btn);
mpopupwindow = new popupwindow(view, linearlayout.layoutparams.wrap_content,
linearlayout.layoutparams.wrap_content);
/**
* 先调用下measure,否则拿不到宽和高
*/
mpopupwindow.getcontentview().measure(0, 0);
mpopupwindowheight = mpopupwindow.getcontentview().getmeasuredheight();
mpopupwindowwidth = mpopupwindow.getcontentview().getmeasuredwidth();
}
@override
public boolean dispatchtouchevent(motionevent ev)
{
int action = ev.getaction();
int x = (int) ev.getx();
int y = (int) ev.gety();
switch (action)
{
case motionevent.action_down:
xdown = x;
ydown = y;
/**
* 如果当前popupwindow显示，则直接隐藏，然后屏蔽listview的touch事件的下传
*/
if (mpopupwindow.isshowing())
{
dismisspopwindow();
return false;
}
// 获得当前手指按下时的item的位置
mcurrentviewpos = pointtoposition(xdown, ydown);
// 获得当前手指按下时的item
view view = getchildat(mcurrentviewpos - getfirstvisibleposition());
mcurrentview = view;
break;
case motionevent.action_move:
xmove = x;
ymove = y;
int dx = xmove - xdown;
int dy = ymove - ydown;
/**
* 判断是否是从右到左的滑动
*/
if (xmove < xdown && math.abs(dx) > touchslop && math.abs(dy) < touchslop)
{
// log.e(tag, "touchslop = " + touchslop + " , dx = " + dx +
// " , dy = " + dy);
issliding = true;
}
break;
}
return super.dispatchtouchevent(ev);
}
@override
public boolean ontouchevent(motionevent ev)
{
int action = ev.getaction();
/**
* 如果是从右到左的滑动才相应
*/
if (issliding)
{
switch (action)
{
case motionevent.action_move:
int[] location = new int[2];
// 获得当前item的位置x与y
mcurrentview.getlocationonscreen(location);
// 设置popupwindow的动画
mpopupwindow.setanimationstyle(r.style.popwindow_delete_btn_anim_style);
mpopupwindow.update();
mpopupwindow.showatlocation(mcurrentview, gravity.left | gravity.top,
location[0] + mcurrentview.getwidth(), location[1] + mcurrentview.getheight() / 2
- mpopupwindowheight / 2);
// 设置删除按钮的回调
mdelbtn.setonclicklistener(new onclicklistener()
{
@override
public void onclick(view v)
{
if (mlistener != null)
{
mlistener.clickhappend(mcurrentviewpos);
mpopupwindow.dismiss();
}
}
});
// log.e(tag, "mpopupwindow.getheight()=" + mpopupwindowheight);
break;
case motionevent.action_up:
issliding = false;
}
// 相应滑动期间屏幕itemclick事件，避免发生冲突
return true;
}
return super.ontouchevent(ev);
}
/**
* 隐藏popupwindow
*/
private void dismisspopwindow()
{
if (mpopupwindow != null && mpopupwindow.isshowing())
{
mpopupwindow.dismiss();
}
}
public void setdelbuttonclicklistener(delbuttonclicklistener listener)
{
mlistener = listener;
}
interface delbuttonclicklistener
{
public void clickhappend(int position);
}
}
代码注释写得很详细，简单说一下，在dispatchtouchevent中设置当前是否响应用户滑动，然后在ontouchevent中判断是否响应，如果响应则popupwindow以动画的形式展示出来。当然屏幕上如果存在popupwindow则屏幕listview的滚动与item的点击，以及从右到左滑动时屏幕item的click事件。
接下来是mainactivity.java，这里代码很简单不做介绍了。
package com.example.listviewitemslidedeletebtnshow;
import java.util.arraylist;
import java.util.arrays;
import java.util.list;
import android.app.activity;
import android.os.bundle;
import android.view.view;
import android.widget.adapterview;
import android.widget.adapterview.onitemclicklistener;
import android.widget.arrayadapter;
import android.widget.toast;
import com.example.listviewitemslidedeletebtnshow.qqlistview.delbuttonclicklistener;
public class mainactivity extends activity
{
private qqlistview mlistview;
private arrayadapter<string> madapter;
private list<string> mdatas;
@override
protected void oncreate(bundle savedinstancestate)
{
super.oncreate(savedinstancestate);
setcontentview(r.layout.activity_main);
mlistview = (qqlistview) findviewbyid(r.id.id_listview);
// 不要直接arrays.aslist
mdatas = new arraylist<string>(arrays.aslist("helloworld", "welcome", "java", "android", "servlet", "struts",
"hibernate", "spring", "html5", "javascript", "lucene"));
madapter = new arrayadapter<string>(this, android.r.layout.simple_list_item_1, mdatas);
mlistview.setadapter(madapter);
mlistview.setdelbuttonclicklistener(new delbuttonclicklistener()
{
@override
public void clickhappend(final int position)
{
toast.maketext(mainactivity.this, position + " : " + madapter.getitem(position), 1).show();
madapter.remove(madapter.getitem(position));
}
});
mlistview.setonitemclicklistener(new onitemclicklistener()
{
@override
public void onitemclick(adapterview<?> parent, view view, int position, long id)
{
toast.maketext(mainactivity.this, position + " : " + madapter.getitem(position), 1).show();
}
});
}
}
效果图如下：楼主使用asm.jar以及gifcamera截的gif，由于button的动画很短感觉截图效果很卡不流畅，大家有什么好的截图，还望推荐。有兴趣的还是下载源码看看效果i。
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