在实际项目中删除列表中的某一项是非常常见的功能，传统的做法可以使用长按监听器等，而现在流行的做法是左滑弹出删除按钮，微信，qq等都是这么做的，下面做一个示例，代码如下：
主页面mainactivity：代码比较简单常规
我要评论
package com.home.testslideview;
import java.util.arraylist;
import java.util.list;
import android.app.activity;
import android.os.bundle;
import android.widget.listview;
import com.home.textslideview.r;
public class mainactivity extends activity {
private listview listview;
private list<newinfobean> list = new arraylist<newinfobean>();
// 适配器
private slideadapter adapter;
@override
protected void oncreate(bundle savedinstancestate) {
super.oncreate(savedinstancestate);
setcontentview(r.layout.main);
initview();
initdata();
setadapter();
}
/**
* 初始化页面控件
*/
private void initview() {
listview = (listview) findviewbyid(r.id.main_lv);
}
/**
* 初始化数据
*/
private void initdata() {
list.add(new newinfobean("这是测试内容1"));
list.add(new newinfobean("这是测试内容2"));
list.add(new newinfobean("这是测试内容3"));
list.add(new newinfobean("这是测试内容4"));
list.add(new newinfobean("这是测试内容5"));
list.add(new newinfobean("这是测试内容6"));
list.add(new newinfobean("这是测试内容7"));
list.add(new newinfobean("这是测试内容8"));
list.add(new newinfobean("这是测试内容9"));
list.add(new newinfobean("这是测试内容10"));
}
/**
* 设置适配器
*/
private void setadapter() {
if (adapter == null) {
adapter = new slideadapter(this, list);
listview.setadapter(adapter);
} else {
adapter.setlist(list);
adapter.notifydatasetchanged();
}
}
}
实体类newinfobean：具体项目中由自己定义：
package com.home.testslideview;
public class newinfobean {
public slideview slideview;
private string content;
public slideview getslideview() {
return slideview;
}
public void setslideview(slideview slideview) {
this.slideview = slideview;
}
public string getcontent() {
return content;
}
public void setcontent(string content) {
this.content = content;
}
public newinfobean() {
super();
}
public newinfobean(string content) {
super();
this.content = content;
}
}
适配器slideadapter：也比较简单
package com.home.testslideview;
import java.util.list;
import android.content.context;
import android.util.sparsearray;
import android.view.layoutinflater;
import android.view.view;
import android.view.view.onclicklistener;
import android.view.viewgroup;
import android.widget.baseadapter;
import android.widget.textview;
import com.home.testslideview.slideview.onslidelistener;
import com.home.textslideview.r;
public class slideadapter extends baseadapter implements onslidelistener,
onclicklistener {
private layoutinflater inflater;
private list<newinfobean> list;
private context context;
public slideadapter(context context, list<newinfobean> list) {
if (inflater == null) {
inflater = layoutinflater.from(context);
}
this.list = list;
this.context = context;
}
@override
public int getcount() {
return list.size();
}
@override
public object getitem(int position) {
return list.get(position);
}
@override
public long getitemid(int position) {
return position;
}
@override
public view getview(int position, view convertview, viewgroup arg2) {
slideview slideview = (slideview) convertview;
newinfobean bean = list.get(position);
if (slideview == null) {
slideview = new slideview(context);
slideview.setonslidelistener(this);
}
// 设置内容
textview contenttext = getadapterview(slideview,
r.id.slideview_tv_content, position);
contenttext.settext(bean.getcontent());
// 删除按钮
textview deltext = getadapterview(slideview, r.id.slideview_tv_del,
position);
deltext.setonclicklistener(this);
bean.slideview = slideview;
bean.slideview.shrink();
return slideview;
}
@suppresswarnings("unchecked")
public <t extends view> t getadapterview(view convertview, int id,
object tag) {
sparsearray<view> viewholder = null;
try {
if (convertview.gettag(r.id.view_holder) instanceof sparsearray<?>) {
viewholder = (sparsearray<view>) convertview
.gettag(r.id.view_holder);
}
} catch (classcastexception e) {
}
if (viewholder == null) {
viewholder = new sparsearray<view>();
convertview.settag(r.id.view_holder, viewholder);
convertview.settag(r.id.order_id, tag);
}
view childview = viewholder.get(id);
if (childview == null) {
childview = convertview.findviewbyid(id);
childview.settag(tag);
viewholder.put(id, childview);
}
return (t) childview;
}
public list<newinfobean> getlist() {
return list;
}
public void setlist(list<newinfobean> list) {
this.list = list;
}
@override
public void onslide(view view, int status) {
}
@override
public void onclick(view v) {
switch (v.getid()) {
case r.id.slideview_tv_del:
int position = (integer) v.gettag();
list.remove(position);
notifydatasetchanged();
break;
default:
break;
}
}
}
比较关键的两个类：
自定义的listview：slidelistview
package com.home.testslideview;
import android.content.context;
import android.util.attributeset;
import android.view.motionevent;
import android.view.view;
import android.widget.listview;
public class slidelistview extends listview {
private slideview itemview;
public slidelistview(context context) {
super(context);
}
public slidelistview(context context, attributeset attrs) {
super(context, attrs);
}
public void shrinklistitem(int position) {
view item = getchildat(position);
if (item != null) {
try {
((slideview) item).shrink();
} catch (classcastexception e) {
e.printstacktrace();
}
}
}
@override
public boolean ontouchevent(motionevent event) {
switch (event.getaction()) {
case motionevent.action_down: {
int x = (int) event.getx();
int y = (int) event.gety();
int position = pointtoposition(x, y);
if (position != invalid_position) {
newinfobean data = (newinfobean) getitematposition(position);
itemview = data.slideview;
}
}
default:
break;
}
if (itemview != null) {
itemview.onrequiretouchevent(event);
}
return super.ontouchevent(event);
}
}
自定义的listview中的每一行控件：slideview(借鉴网上的一个示例)：
package com.home.testslideview;
import android.content.context;
import android.util.attributeset;
import android.util.log;
import android.util.typedvalue;
import android.view.layoutinflater;
import android.view.motionevent;
import android.view.view;
import android.widget.linearlayout;
import android.widget.scroller;
import com.home.textslideview.r;
public class slideview extends linearlayout {
private static final string tag = slideview.class.getsimplename();
private context mcontext;
private scroller mscroller;
private onslidelistener monslidelistener;
private int mholderwidth = 80;
private int mlastx = 0;
private int mlasty = 0;
private static final int tan = 2;
private layoutinflater inflater;
public interface onslidelistener {
public static final int slide_status_off = 0;
public static final int slide_status_start_scroll = 1;
public static final int slide_status_on = 2;
/**
* @param view
* current slideview
* @param status
* slide_status_on or slide_status_off
*/
public void onslide(view view, int status);
}
public slideview(context context) {
super(context);
initview();
}
public slideview(context context, attributeset attrs) {
super(context, attrs);
initview();
}
private void initview() {
mcontext = getcontext();
if (inflater == null) {
inflater = layoutinflater.from(mcontext);
}
mscroller = new scroller(mcontext);
setorientation(linearlayout.horizontal);
view.inflate(mcontext, r.layout.slide_view_merge, this);
mholderwidth = math.round(typedvalue.applydimension(
typedvalue.complex_unit_dip, mholderwidth, getresources()
.getdisplaymetrics()));
}
public void setonslidelistener(onslidelistener onslidelistener) {
monslidelistener = onslidelistener;
}
public void shrink() {
if (getscrollx() != 0) {
this.smoothscrollto(0, 0);
}
}
public void onrequiretouchevent(motionevent event) {
int x = (int) event.getx();
int y = (int) event.gety();
int scrollx = getscrollx();
log.d(tag, "x=" + x + " y=" + y);
switch (event.getaction()) {
case motionevent.action_down: {
if (!mscroller.isfinished()) {
mscroller.abortanimation();
}
if (monslidelistener != null) {
monslidelistener.onslide(this,
onslidelistener.slide_status_start_scroll);
}
break;
}
case motionevent.action_move: {
int deltax = x - mlastx;
int deltay = y - mlasty;
if (math.abs(deltax) < math.abs(deltay) * tan) {
break;
}
int newscrollx = scrollx - deltax;
if (deltax != 0) {
if (newscrollx < 0) {
newscrollx = 0;
} else if (newscrollx > mholderwidth) {
newscrollx = mholderwidth;
}
this.scrollto(newscrollx, 0);
}
break;
}
case motionevent.action_up: {
int newscrollx = 0;
if (scrollx - mholderwidth * 0.75 > 0) {
newscrollx = mholderwidth;
}
this.smoothscrollto(newscrollx, 0);
if (monslidelistener != null) {
monslidelistener.onslide(this,
newscrollx == 0 ? onslidelistener.slide_status_off
: onslidelistener.slide_status_on);
}
break;
}
default:
break;
}
mlastx = x;
mlasty = y;
}
private void smoothscrollto(int destx, int desty) {
// 缓慢滚动到指定位置
int scrollx = getscrollx();
int delta = destx - scrollx;
mscroller.startscroll(scrollx, 0, delta, 0, math.abs(delta) * 3);
invalidate();
}
@override
public void computescroll() {
if (mscroller.computescrolloffset()) {
scrollto(mscroller.getcurrx(), mscroller.getcurry());
postinvalidate();
}
}
}
main.xml：
<?xml version="1.0" encoding="utf-8"?> <linearlayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" > <com.home.testslideview.slidelistview android:id="@+id/main_lv" android:layout_width="match_parent" android:layout_height="match_parent" android:cachecolorhint="#00000000" android:fadingedge="none" android:listselector="#00000000" android:scrollbars="none" /> </linearlayout>
slide_view_merge.xml：
<?xml version="1.0" encoding="utf-8"?> <merge xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="horizontal" > <linearlayout android:id="@+id/slideview_layout_content" android:layout_width="match_parent" android:layout_height="match_parent" android:layout_gravity="center_vertical" android:gravity="center_vertical" android:orientation="horizontal" > <textview android:id="@+id/slideview_tv_content" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="内容部分"/> </linearlayout> <linearlayout android:id="@+id/view_layout_del" android:layout_width="80dp" android:layout_height="match_parent" android:layout_gravity="center_vertical" android:layout_torightof="@id/slideview_layout_content" android:clickable="true" android:gravity="center_vertical" android:orientation="horizontal" > <textview android:id="@+id/slideview_tv_del" android:layout_width="80dp" android:layout_height="match_parent" android:layout_marginbottom="2dp" android:gravity="center" android:padding="15dp" android:text="删除"/> </linearlayout> </merge>
源码下载：
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持移动技术网。
如对本文有疑问， 点击进行留言回复！！
网友评论