后退事件处理

private longToatlong;

@Override

public voidonBackPressed() {

//        super.onBackPressed();

if(Toatlong<=0){

Toast.makeText(MainActivity.this,"再按一次退出",Toast.LENGTH_SHORT).show();

Toatlong= System.currentTimeMillis();

}else{

longcurrentTime = System.currentTimeMillis();

if(currentTime-Toatlong<=1000){

finish();

}else{

Toatlong= currentTime;

Toast.makeText(MainActivity.this,"再按一次退出",Toast.LENGTH_SHORT).show();

}

}

}