本文实例为大家分享了chronometer实现倒计时功能，android提供了实现按照秒计时的api，供大家参考，具体内容如下
一、自定义chronometerview 继续自textview
主要原理：先设置一个基准倒计时时间mbaseseconds，内置handler 每隔1s发送一个空消息，mremainseconds--，同时刷新界面视图，回调给外部调用者，只到为零。外部调用者可通过start()/pause()/stop()来控制计时器的工作状态。
可以app中发送短信验证码的场景为例，做了一个很粗糙的界面，但功能都实现了。
/**
* @name 倒计时器(类似妙表倒数计时，支持暂停、停止、重新开始)
* @author fanjb
* @date 11月6日
*/
public class chronometerview extends textview {
/**
* a callback that notifies when the chronometer has decremented on its own.
*
* @author fanjb
*/
public interface ontickchangelistener {
/**
* remain seconds changed
*
* @param view
* @param remainseconds
*/
public void ontickchanged(chronometerview view, long remainseconds);
}
private long mbase;
private long mremainseconds;
private boolean mstarted;
private boolean mrestart;
private boolean mvisible;
private boolean misenable;
private ontickchangelistener mticklistener;
public chronometerview(context context) {
this(context, null);
}
public chronometerview(context context, attributeset attrs) {
super(context, attrs, 0);
}
public chronometerview(context context, attributeset attrs, int defstyleattr) {
super(context, attrs, defstyleattr);
updatetext(mremainseconds);
}
@override
protected void onwindowvisibilitychanged(int visibility) {
super.onwindowvisibilitychanged(visibility);
mvisible = visibility == visible;
updatestatus();
}
@override
protected void ondetachedfromwindow() {
super.ondetachedfromwindow();
mvisible = false;
updatestatus();
}
/**
* 启动计时器
*/
public void start() {
if (mrestart && !mstarted) {
mremainseconds = mbase;
}
mstarted = true;
updatestatus();
}
/**
* 暂停计时器
*/
public void pause() {
if (mstarted) {
mstarted = mrestart = false;
updatestatus();
}
}
/**
* 停止计时器，再次调用 start()重新启动
*/
public void stop() {
mstarted = false;
mrestart = true;
updatestatus();
updatetext(mremainseconds = 0);
dispatchticklistener();
}
/**
* 刷新内部状态
*/
private void updatestatus() {
boolean isenable = mvisible && mstarted;
if (misenable != isenable) {
if (isenable) {
mhandler.sendmessage(message.obtain(mhandler, tick_what));
} else {
mhandler.removemessages(tick_what);
}
misenable = isenable;
}
}
private static final int tick_what = 1;
private handler mhandler = new handler() {
public void handlemessage(android.os.message msg) {
if (mremainseconds > 0) {
updatetext(--mremainseconds);
dispatchticklistener();
sendmessagedelayed(message.obtain(this, tick_what), 1000);
}
}
};
private void updatetext(long now) {
string text = dateutils.formatelapsedtime(now);
settext(text);
}
/**
* 在未启动状态下设置开始倒计时时间
*
* @param baseseconds
*/
public void setbaseseconds(long baseseconds) {
if (baseseconds > 0 && baseseconds != mbase && !mstarted) {
mbase = mremainseconds = baseseconds;
updatetext(mremainseconds);
}
}
/**
* 剩余时间
*
* @return
*/
public long getremainseconds() {
return mremainseconds;
}
public void setontickchangelistener(ontickchangelistener listener) {
mticklistener = listener;
}
public ontickchangelistener getticklistener() {
return mticklistener;
}
private void dispatchticklistener() {
if (mticklistener != null) {
mticklistener.ontickchanged(this, getremainseconds());
}
}
@override
public void oninitializeaccessibilityevent(accessibilityevent event) {
super.oninitializeaccessibilityevent(event);
event.setclassname(chronometerview.class.getname());
}
@override
public void oninitializeaccessibilitynodeinfo(accessibilitynodeinfo info) {
super.oninitializeaccessibilitynodeinfo(info);
info.setclassname(chronometer.class.getname());
}
}
二、xml 中没有加入自定义的控件属性，同textview
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal" >
android:id="@+id/chronometer_view"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginleft="5dp"
android:background="@drawable/chronometer_view_bg"
android:enabled="true"
android:text="00:00" />
android:id="@+id/start_chronometer_view_btn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginleft="5dp"
android:text="start" />
android:id="@+id/pause_chronometer_view_btn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginleft="5dp"
android:text="pause" />
android:id="@+id/stop_chronometer_view_btn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginleft="5dp"
android:text="stop" />
三、在activity中做一个简单的测试(可以发送短信验证码的实际应用场景为例)
public class chronometeractivity extends activity {
private chronometerview mchronometerview;
@override
protected void oncreate(bundle savedinstancestate) {
super.oncreate(savedinstancestate);
setcontentview(r.layout.activity_clock);
// 自定义计时器
if (mchronometerview == null) {
mchronometerview = (chronometerview) findviewbyid(r.id.chronometer_view);
mchronometerview.setbaseseconds(60);
mchronometerview.setontickchangelistener(new ontickchangelistener() {
@override
public void ontickchanged(chronometerview view, long curtimemills) {
system.out.println(curtimemills);
view.setenabled(curtimemills == 0 || curtimemills == 60);
if (curtimemills == 0) {
mchronometerview.settext("重新发送");
}
}
});
mchronometerview.settext("点击发送验证码");
}
findviewbyid(r.id.start_chronometer_view_btn).setonclicklistener(mclicklistener);
findviewbyid(r.id.pause_chronometer_view_btn).setonclicklistener(mclicklistener);
findviewbyid(r.id.stop_chronometer_view_btn).setonclicklistener(mclicklistener);
}
private view.onclicklistener mclicklistener = new onclicklistener() {
@override
public void onclick(view v) {
switch (v.getid()) {
case r.id.start_chronometer_view_btn:
if (mchronometerview != null) {
mchronometerview.start();
}
break;
case r.id.pause_chronometer_view_btn:
if (mchronometerview != null) {
mchronometerview.pause();
}
break;
case r.id.stop_chronometer_view_btn:
if (mchronometerview != null) {
mchronometerview.stop();
}
break;
}
}
};
}
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萬仟网。
