MainActivity.java
package com.jing.example.nknu_.android_handler_message;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity {
private Button button;
private static TextView textView;
private static Handler handler = new Handler(){
@Override
public void handleMessage(android.os.Message msg){
super.handleMessage(msg);
if(msg.what==3) {
textView.setText("-->>" + msg.arg1 + "-->>" + msg.obj);
}
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
button = (Button)this.findViewById(R.id.button);
textView = (TextView)this.findViewById(R.id.msg);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
new Thread(new MyThread()).start();
}
});
}
public class MyThread implements Runnable{
@Override
public void run() {
/* 第一種寫法
將一個Message 追加到消息隊列的尾部，並且由Handler發送
Message message = Message.obtain();
message.arg1 = 2;
message.obj = "jack";
handler.sendMessage(message);
*/
/*第二種寫法
Message message = Message.obtain(handler);
message.arg1 = 2;
message.obj = "rose";
message.sendToTarget();
*/
/*第三種寫法
Message message = Message.obtain(handler,2);
message.arg1 = 34;
message.obj = "XX";
message.sendToTarget();
*/
/*第四種
Message message = Message.obtain(handler,2,1,1,"TTT");
message.sendToTarget();
*/
/*第五種
Message message = handler.obtainMessage();
message.arg1 = 23;
message.obj = "jack";
message.sendToTarget();
*/
//創建Message的方法有很多種
/*第六種
Message message = handler.obtainMessage(1,2,3,"Jack");
message.sendToTarget();
*/
//Message message = Message.obtain();
//發送空消息
//handler.sendEmptyMessage(3);
//延遲發送空消息
//handler.sendEmptyMessageDelayed(3,4000);
Message msg = Message.obtain();
msg.what = 3;
msg.arg1 = 23;
msg.obj = "rose";
handler.sendMessageDelayed(msg,4000);
}
}
}
content_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context="com.jing.example.nknu_.android_handler_message.MainActivity"
tools:showIn="@layout/activity_main">
<TextView
android:id="@+id/msg"
android:textSize="40sp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Hello World!" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="測試handle發送Messager"
android:id="@+id/button"
android:layout_centerVertical="true"
android:layout_alignParentStart="true" />
</RelativeLayout>