android:onClick - 定義 onClick 事件回調函數

我們可以在佈局文件(main.xml)中通過 android:onClick 屬性, 直接定義 onClick 事件的回調函數.

實例:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="@string/hello"
    />
<Button  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="Click Me"
    android:onClick="onClick"
    />
</LinearLayout>

package com.AndroidOnClick;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Toast;

public class AndroidOnClickActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
    }
    
    public void onClick(View view){
     Toast.makeText(AndroidOnClickActivity.this, 
       "Button Clicked", Toast.LENGTH_LONG).show();
    }
}