共有两种效果:
第一种效果图如图:
在MainActivity中加几句话即可:
AlertDialog builder=null;
@Override
public boolean onKeyUp(int keyCode, KeyEvent event) {
if(keyCode == KeyEvent.KEYCODE_BACK){
builder = new AlertDialog.Builder(MainActivity.this)
.setTitle("温馨提示:")
.setMessage("您是否要退出程序?")
.setPositiveButton("确定",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,
int whichButton) {
MainActivity.this.finish();
}
})
.setNegativeButton("取消",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,
int whichButton) {
builder.dismiss();
}
}).show();
}
return true;
}
第二种效果图如下
在MainActivity
private long pressTime = 0;
@Override
public void onBackPressed() {
if (System.currentTimeMillis() - pressTime > 2000){
Toast.makeText(this, "再按一次退出程序", Toast.LENGTH_SHORT).show();
pressTime = System.currentTimeMillis();
}else {
this.finish();
}
}