package com.example.demo1;

import android.annotation.SuppressLint;

import android.app.Activity;

import android.content.Intent;

import android.os.Bundle;

import android.os.Handler;

import android.os.Message;

import android.view.Menu;

import android.view.MenuItem;

import android.widget.TextView;

public class MainActivity extends Activity {

private TextView tv1;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

tv1 = (TextView) findViewById(R.id.textView1);

handler.post(waitSendsRunnable);

}

//启用一个Handler

Handler handler = new Handler() {

@SuppressLint("HandlerLeak")

public void handleMessage(Message msg) {

super.handleMessage(msg);

switch (msg.what) {

case 0:

Intent intent = new Intent(MainActivity.this, MainActivity2.class);

startActivity(intent);

break;

case 1:

tv1.setText("倒计时：" + index + "s");

break;

default:

break;

}

}

};

// 倒计时五秒

int index = 5;

Runnable waitSendsRunnable = new Runnable() {

public void run() {

if (index > 0) {

index--;

try {

Thread.sleep(1000);

handler.sendEmptyMessage(1);

} catch (InterruptedException e) {

e.printStackTrace();

}

handler.post(waitSendsRunnable);

} else {

try {

Thread.sleep(1000);

handler.sendEmptyMessage(0);

} catch (InterruptedException e) {

e.printStackTrace();

}

}

}

};

}