Handler倒计时

//main主页面
import android.content.Intent;
import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.TextView;

import com.example.lianxiyuekao.R;

public class MainActivity extends AppCompatActivity {

private TextView mtime;
private int time=5;
private Handler handler=new Handler(){
    @Override
    public void handleMessage(Message msg) {
        super.handleMessage(msg);
        time--;
        if (time<=0){
            Intent intent = new Intent(MainActivity.this, Main2Activity.class);
            startActivity(intent);
            finish();
        }else{
            mtime.setText(time+\"S\");
            handler.sendEmptyMessageDelayed(1,1000);
        }
    }
};

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    mtime = (TextView) findViewById(R.id.mtime);
    handler.sendEmptyMessageDelayed(1,1000);
}

}

//mian布局