MainActivity.java
package com.jing.example.nknu_.android_handler_looper;
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 TextView textView;
private Handler handler = new Handler(){
@Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
textView.setText((msg.obj.toString()));
}
};
@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.textView);
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() {
try {
Thread.sleep(3000);
} catch (InterruptedException e) {
e.printStackTrace();
}
Message message = Message.obtain();
message.obj = "hello world";
handler.sendMessage(message);
}
}
}
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_looper.MainActivity"
tools:showIn="@layout/activity_main">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="New Button"
android:id="@+id/button"
android:layout_centerVertical="true"
android:layout_centerHorizontal="true" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="New Text"
android:id="@+id/textView"
android:layout_marginTop="86dp"
android:textSize="40sp"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true" />
</RelativeLayout>