Android_01_点击事件中View对象的作用

package com.itheima.clickevent;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class MainActivity extends Activity{

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

}

//View：系统会把触发这个方法的那个组件的对象作为view对象传进来
public void getScore(View v){
//通过对view对象的判断，就可以知道用户点击的到底是哪一个按钮
//拿到按钮的id
int id = v.getId();
switch (id) {
case R.id.wangzhe:
System.out.println("下辈子吧");
break;
case R.id.diamond:
System.out.println("凑合凑合");
break;
case R.id.master:
System.out.println("想想就好");
break;

}
}

}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
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"
tools:context=".MainActivity"
android:orientation="vertical"
>

<Button
android:id="@+id/wangzhe"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="点我上王者"
android:onClick="getScore"
/>
<Button
android:id="@+id/diamond"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="点我上钻"
android:onClick="getScore"
/>
<Button
android:id="@+id/master"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="点我上大师"
android:onClick="getScore"
/>

</LinearLayout>