再按一次退出程序 android,Android 再按一次退出程序的实现方法

第一种(handler+标志位)

private boolean isexit;

private handler handler;

@override

protected void oncreate(bundle savedinstancestate) {

super.oncreate(savedinstancestate);

setcontentview(r.layout.activity_main);

handler = new handler(){

@override

public void handlemessage(message msg) {

super.handlemessage(msg);

isexit = false;

}

};

}

public boolean onkeydown(int keycode, keyevent event) {

if(keycode==keyevent.keycode_back){

if(!isexit){

isexit = true;

handler.sendemptymessagedelayed(0, 1500);

toast.maketext(this, "再按一次推出程序", 1000).show();

return false;

}else{

finish();

}

}

return super.onkeydown(keycode, event);

}

第二种(记录点击的时间)

private long exittimemillis = system.currenttimemillis();

@override

protected void oncreate(bundle savedinstancestate) {

super.oncreate(savedinstancestate);

setcontentview(r.layout.activity_main);

}

@override

public boolean onkeydown(int keycode, keyevent event) {

if(keycode==keyevent.keycode_back){

long currenttime = system.currenttimemillis();

if(currenttime-exittimemillis==0||currenttime-exittimemillis>1500){

exittimemillis = system.currenttimemillis();

toast.maketext(this, "再按一次推出程序", 1000).show();

return false;

}else{

finish();

}

}

return super.onkeydown(keycode, event);

}