这个例子主要演示了主,子线程之间的信息交互
- package com.example.Looper_04;
- import android.app.Activity;
- import android.content.Context;
- import android.graphics.Color;
- import android.os.Bundle;
- import android.os.Handler;
- import android.os.Looper;
- import android.os.Message;
- import android.view.View;
- import android.view.View.OnClickListener;
- import android.widget.Button;
- import android.widget.LinearLayout;
- import android.widget.TextView;
- public class Looper_04 extends Activity implements OnClickListener {
- private final int WC = LinearLayout.LayoutParams.WRAP_CONTENT;
- private final int FP = LinearLayout.LayoutParams.FILL_PARENT;
- public TextView tv;
- private myThread t;
- private Button btn, btn2;
- private Handler h;
- private Context ctx;
- public void onCreate(Bundle icicle) {
- super.onCreate(icicle);
- ctx = this;
- LinearLayout layout = new LinearLayout(this);
- layout.setOrientation(LinearLayout.VERTICAL);
- btn = new Button(this);
- btn.setId(101);
- btn.setBackgroundResource(R.drawable.icon);
- btn.setText("test looper");
- btn.setOnClickListener(this);
- LinearLayout.LayoutParams param = new LinearLayout.LayoutParams(100, 50);
- param.topMargin = 10;
- layout.addView(btn, param);
- btn2 = new Button(this);
- btn2.setId(102);
- btn2.setBackgroundResource(R.drawable.icon);
- btn2.setText("exit");
- btn2.setOnClickListener(this);
- layout.addView(btn2, param);
- tv = new TextView(this);
- tv.setTextColor(Color.WHITE);
- tv.setText("");
- LinearLayout.LayoutParams param2 = new LinearLayout.LayoutParams(FP, WC);
- param2.topMargin = 10;
- layout.addView(tv, param2);
- setContentView(layout);
- // 这里执行了子线程
- t = new myThread();
- t.start();
- }
- public void onClick(View v) {
- switch (v.getId()) {
- case 101:
- String obj = "mainThread";
- Message m = h.obtainMessage(1, 1, 1, obj);
- // 发送的消息由子线程的handler来进行处理
- h.sendMessage(m);
- break;
- case 102:
- h.getLooper().quit();
- finish();
- break;
- }
- }
- // ------------------------------------------------
- public class EventHandler extends Handler {
- public EventHandler(Looper looper) {
- super(looper);
- }
- @Override
- public void handleMessage(Message msg) {
- ((Activity) ctx).setTitle((String) msg.obj);
- }
- }
- // ------------------------------------------------
- class myThread extends Thread {
- public void run() {
- // 初始化当前子线程的Looper物件之管理对象
- Looper.prepare();
- h = new Handler() {
- public void handleMessage(Message msg) {
- //又建立了主线程的handler对象
- EventHandler ha = new EventHandler(Looper.getMainLooper());
- String obj = (String) msg.obj + ", myThread";
- Message m = ha.obtainMessage(1, 1, 1, obj);
- ha.sendMessage(m);
- }
- };
- Looper.loop();
- }
- }
- }