本文实例讲述了android开发之viewswitcher用法。分享给大家供大家参考，具体如下：
android.widget.viewswitcher是viewanimator的子类，用于在两个view之间切换，但每次只能显示一个view。
viewswitcher的addview函数的代码如下：
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/**
* {@inheritdoc}
*
* @throws illegalstateexception if this switcher already contains two children
*/
@override
public void addview(view child, int index, viewgroup.layoutparams params) {
if (getchildcount() >= 2) {
throw new illegalstateexception("can't add more than 2 views to a viewswitcher");
}
super.addview(child, index, params);
}
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可以看出，若view的数量超过两个，会抛出异常：java.lang.illegalstateexception，打印 "can't add more than 2 views to a viewswitcher" 。你可以使用viewswitcher的factory创建view或添加自己创建的view。
下面用一个例子介绍一下viewswitcher的用法。
布局文件：activity_main.xml
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<?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:orientation="vertical"
tools:context=".mainactivity" >
<linearlayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<button
android:id="@+id/prev"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="previous" />
<button
android:id="@+id/next"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="next" />
</linearlayout>
<viewswitcher
android:id="@+id/viewswitcher"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<imageview
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/ic_launcher" />
<linearlayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:orientation="vertical" >
<button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="- button 2 -" />
<textview
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="linearlayout 2" />
</linearlayout>
</viewswitcher>
</linearlayout>
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activity的代码：
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package com.example.androidtest;
import android.app.activity;
import android.os.bundle;
import android.view.view;
import android.view.animation.animation;
import android.view.animation.animationutils;
import android.widget.button;
import android.widget.viewswitcher;
public class myactivity extends activity {
button buttonprev, buttonnext;
viewswitcher viewswitcher;
animation slide_in_left, slide_out_right;
@override
protected void oncreate(bundle savedinstancestate) {
super.oncreate(savedinstancestate);
setcontentview(r.layout.activity_main);
buttonprev = (button) findviewbyid(r.id.prev);
buttonnext = (button) findviewbyid(r.id.next);
viewswitcher = (viewswitcher) findviewbyid(r.id.viewswitcher);
slide_in_left = animationutils.loadanimation(this,
android.r.anim.slide_in_left);
slide_out_right = animationutils.loadanimation(this,
android.r.anim.slide_out_right);
viewswitcher.setinanimation(slide_in_left);
viewswitcher.setoutanimation(slide_out_right);
buttonprev.setonclicklistener(new view.onclicklistener() {
@override
public void onclick(view arg0) {
viewswitcher.showprevious();
}
});
buttonnext.setonclicklistener(new view.onclicklistener() {
@override
public void onclick(view arg0) {
viewswitcher.shownext();
}
});
;
}
}
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实现效果图：
使用viewswitcher的setfactory设置切换的view，分为两步。
第一步：获得viewswithcer的实例
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switcher = (viewswitcher) findviewbyid(r.id.viewswitcher);
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第二部：实现接口viewfactory
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switcher.setfactory(new viewfactory()
{
@override
public view makeview()
{
return inflater.inflate(r.layout.slidelistview, null);
}
});
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希望本文所述对大家android程序设计有所帮助。