Handler发送Message

    用Handler更新UI

package activity.cyq.handlermessage;

import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;


public class MainActivity extends AppCompatActivity {
    private TextView textView;
    private Button button;
    private ImageView imageView;

    private int[] iamgeId = new int[]{R.drawable.aaa1, R.drawable.aaa3, R.drawable.image1};


    private Handler handler = new Handler(new Handler.Callback() {
        @Override
        public boolean handleMessage(Message msg) {
            Toast.makeText(MainActivity.this, "这是Handler的回掉函数", Toast.LENGTH_SHORT).show();
            /*如果返回true则终止handler()的执行 ，可用于对message内容进行判断，今儿决定是否继续对messsage的处理*/
            return false;
        }
    }) {
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            textView.setText(msg.arg1 + "" + msg.arg2);
            imageView.setImageBitmap((Bitmap) msg.obj);
        }
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        textView = (TextView) findViewById(R.id.textView);
        button = (Button) findViewById(R.id.button);
        imageView = (ImageView) findViewById(R.id.imageView);
        /*通过handler.post(Runnable)方法根性UI*/
        new Thread() {
            @Override
            public void run() {
                super.run();
                /*创建一个Bitmap对象*/
                Resources res = getResources();
                Bitmap bmp = BitmapFactory.decodeResource(res, R.drawable.aaa1);
                /*发送Message*/
                Message message = new Message();
                message.arg1 = 123;
                message.arg2 = 245;
                message.obj = bmp;
                /* arg1 arg2 是int类型数据 obj为object类型数据 */
                handler.sendMessage(message);
            }
        }.start();


    }


}