本文实例讲述了android编程之简单计时器实现方法。分享给大家供大家参考,具体如下:
这里利用contextmenu(上下文菜单),chronometer实现简单计数器。
main.xml:
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<?xml version= "1.0" encoding= "utf-8" ?>
<linearlayout xmlns:android= "http://schemas.android.com/apk/res/android"
android:orientation= "vertical"
android:layout_width= "fill_parent"
android:layout_height = "fill_parent"
android:gravity = "center_horizontal"
>
<chronometer
android:id = "@+id/chronometer"
android:layout_width= "wrap_content"
android:layout_height= "wrap_content"
android:format= "%s"
android:textsize= "80px"
android:textcolor= "#00ff00"
/>
</linearlayout >
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/layout/menu/context_menu.xml
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<?xml version= "1.0" encoding= "utf-8" ?>
<menu xmlns:android= "http://schemas.android.com/apk/res/android" >
<item android:id= "@+id/timer_start" android:title= " 开始计时 " />
<item android:id= "@+id/timer_stop" android:title= " 终止计时 " />
<item android:id= "@+id/timer_reset" android:title= " 清零 " />
</menu>
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主activity:
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public class mainactivity extends activity {
private chronometer timer;
@override
public void oncreate(bundle savedinstancestate)
{
super .oncreate(savedinstancestate);
setcontentview(r.layout.main);
// 获得计时器对象
timer = (chronometer) this .findviewbyid(r.id.chronometer);
//长按计时器时,出现上下文菜单
this .registerforcontextmenu(timer);
}
//创建上下文菜单
@override
public void oncreatecontextmenu(contextmenu menu, view v,
contextmenuinfo menuinfo)
{
super .oncreatecontextmenu(menu, v, menuinfo);
// contextmenu的item不支持icon,所以不用再资源文件中,为它们设定图标
if (v.getid() == r.id.chronometer)
{
//加载xml菜单布局文件
this .getmenuinflater().inflate(r.menu.context_menu, menu);
// 设定头部图标
menu.setheadericon(r.drawable.icon);
// 设定头部标题
menu.setheadertitle( " 计时器控制选项 " );
}
}
//选择菜单项后的响应
@override
public boolean oncontextitemselected(menuitem item)
{
switch (item.getitemid())
{
case r.id.timer_start:
// 将计时器清零
timer.setbase(systemclock.elapsedrealtime());
//开始计时
timer.start();
break ;
case r.id.timer_stop:
//停止计时
timer.stop();
break ;
case r.id.timer_reset:
//将计时器清零
timer.setbase(systemclock.elapsedrealtime());
break ;
}
return super .oncontextitemselected(item);
}
}
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运行结果如图所示:
长按计时器弹出上下文菜单选择开始计时:
希望本文所述对大家android程序设计有所帮助。