Android布局中按钮的设置规则，设置按钮单击事件的三种方法

方法一：布局中只有一个按钮的时候，用匿名内部类，写法如下

package com.example.android_button;import android.support.v7.app.ActionBarActivity;import android.os.Bundle;import android.view.Menu;import android.view.MenuItem;import android.view.View;import android.widget.Button;import android.widget.Toast;public class MainActivity extends ActionBarActivity {private Button btn_s;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);btn_s=(Button) this.findViewById(R.id.btn_s);btn_s.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View arg0) {// TODO Auto-generated method stubToast.makeText(MainActivity.this, "点我一下", 1).show();}});btn_s.setOnLongClickListener(new View.OnLongClickListener() {@Overridepublic boolean onLongClick(View arg0) {// TODO Auto-generated method stubToast.makeText(MainActivity.this, "长按一下", 1).show();return false;}});}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.main, menu);return true;}@Overridepublic boolean onOptionsItemSelected(MenuItem item) {// Handle action bar item clicks here. The action bar will// automatically handle clicks on the Home/Up button, so long// as you specify a parent activity in AndroidManifest.xml.int id = item.getItemId();if (id == R.id.action_settings) {return true;}return super.onOptionsItemSelected(item);}}

<RelativeLayout 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="com.example.android_button.MainActivity" >    <Button        android:id="@+id/btn_s"        android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:text="只有一个按钮"        /></RelativeLayout>

方法二：多个按钮的情况，为了增强代码可读性， OnClickListener接口写法如下

package com.example.android_button;import android.app.Activity;import android.os.Bundle;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.Toast;public class ButtonsActivity extends Activity implements OnClickListener{private Button btn1,btn2,btn3;/** * 要从onCreate开始，不能直接就加载布局，下面的写法不对 *///@Override//public void setContentView(int layoutResID) {//// TODO Auto-generated method stub//super.setContentView(R.layout.button);////btn1=(Button) this.findViewById(R.id.button1);//btn2=(Button) this.findViewById(R.id.button2);//btn3=(Button) this.findViewById(R.id.button3);//////实现监听方法//btn1.setOnClickListener(this);//btn2.setOnClickListener(this);//btn3.setOnClickListener(this);//}/** * 每一个activity（java类）对应一个窗口（xml文件设置窗体布局），都要从onCreate开始 */@Overrideprotected void onCreate(Bundle savedInstanceState) {// TODO Auto-generated method stubsuper.onCreate(savedInstanceState);setContentView(R.layout.button);btn1=(Button) this.findViewById(R.id.button1);btn2=(Button) this.findViewById(R.id.button2);btn3=(Button) this.findViewById(R.id.button3);//实现监听方法btn1.setOnClickListener(this);btn2.setOnClickListener(this);btn3.setOnClickListener(this);}@Overridepublic void onClick(View v) {// TODO Auto-generated method stub//得到按钮的idswitch(v.getId()){case R.id.button1:Toast.makeText(ButtonsActivity.this, "按钮一", 1).show();break;case R.id.button2:Toast.makeText(ButtonsActivity.this, "按钮二", 1).show();break;case R.id.button3:Toast.makeText(ButtonsActivity.this, "按钮三", 1).show();break;}}}

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent" >    <Button        android:id="@+id/button1"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignParentLeft="true"        android:layout_alignParentTop="true"        android:layout_marginLeft="28dp"        android:layout_marginTop="46dp"        android:text="第一个按钮" />    <Button        android:id="@+id/button2"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignLeft="@+id/button1"        android:layout_below="@+id/button1"        android:layout_marginTop="19dp"        android:text="第二个按钮" />    <Button        android:id="@+id/button3"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignLeft="@+id/button2"        android:layout_below="@+id/button2"        android:layout_marginTop="32dp"        android:text="第三个按钮" /></RelativeLayout>

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.example.android_button"    android:versionCode="1"    android:versionName="1.0" >    <uses-sdk        android:minSdkVersion="8"        android:targetSdkVersion="21" />    <application        android:allowBackup="true"        android:icon="@drawable/ic_launcher"        android:label="@string/app_name"        android:theme="@style/AppTheme" >        <activity            android:name=".MainActivity"            android:label="@string/app_name" >          <!--              <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>            -->         </activity>                <!-- 把 ButtonsActivity设置为启动项-->        <activity            android:name=".ButtonsActivity"            >            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>    </application></manifest>

方法三：响应XML定义的事件

XML中代码

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent" >    <!-- 单击的方法名称onClick="sendMessage" -->    <Button        android:id="@+id/btnxml"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignParentLeft="true"        android:layout_alignParentTop="true"        android:layout_marginLeft="104dp"        android:layout_marginTop="216dp"        android:text="Button"        android:onClick="sendMessage"         /></RelativeLayout>

对应的activity中的代码

package com.example.android_button;import android.app.Activity;import android.os.Bundle;import android.view.View;import android.widget.Button;import android.widget.Toast;public class ButtonXML extends Activity{private Button button1;@Overrideprotected void onCreate(Bundle savedInstanceState) {// TODO Auto-generated method stubsuper.onCreate(savedInstanceState);setContentView(R.layout.buttonxml);button1=(Button) this.findViewById(R.id.btnxml);}//响应按钮的点击事件public void sendMessage(View view){Toast.makeText(ButtonXML.this, "响应XML定义的事件", 1).show();}}

运行效果图如下