activity启动模式之singleTop

activity启动模式之singleTop

一、简介

二、设置方法

在AndroidManifest.xml中将要设置为singleTop启动模式的页面进行配置

<activity android:name="activityLaunchSingleTop.ActivityB2" android:launchMode="singleTop"></activity>

三、代码实例

效果图：

代码：

activityLaunchSingleTop.MainActivity

 package activityLaunchSingleTop;

 import com.example.activityLaunchSingleTop.R;

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

 public class MainActivity extends Activity{
     private Button btn_goB1;//创建一个button对象
     private Button btn_goB2;//创建一个button对象
      protected void onCreate(Bundle savedInstanceState) {
             super.onCreate(savedInstanceState);//父类操作
             setContentView(R.layout.activity_main);//引入名为activity_main的界面
             btn_goB1=(Button) findViewById(R.id.btn_goB1);//找id为btn_openActivity的button
             btn_goB1.setOnClickListener(new OnClickListener() {//设置button点击监听

                 @Override
                 public void onClick(View v) {//onclick事件
                     // TODO Auto-generated method stub
                     Intent intent=new Intent();//初始化intent
                     intent.setClass(MainActivity.this,MainActivity.class);//连接
                     startActivity(intent);//打开activity
                 }
             });

             btn_goB2=(Button) findViewById(R.id.btn_goB2);//找id为btn_openActivity的button
             btn_goB2.setOnClickListener(new OnClickListener() {//设置button点击监听

                 @Override
                 public void onClick(View v) {//onclick事件
                     // TODO Auto-generated method stub
                     Intent intent=new Intent();//初始化intent
                     intent.setClass(MainActivity.this,ActivityB2.class);//连接
                     startActivity(intent);//打开activity
                 }
             });
         }
 }

activityLaunchSingleTop.ActivityB2

 package activityLaunchSingleTop;

 import com.example.activityLaunchSingleTop.R;

 import android.app.Activity;
 import android.content.Intent;
 import android.os.Bundle;
 import android.text.InputFilter.LengthFilter;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.widget.Button;
 import android.widget.Toast;

 public class ActivityB2 extends Activity{
     private Button btn_goB1;//创建一个button对象
     private Button btn_goB2;//创建一个button对象
      protected void onCreate(Bundle savedInstanceState) {
             super.onCreate(savedInstanceState);//父类操作
             setContentView(R.layout.activity_b2);//引入名为activity_main的界面
             btn_goB1=(Button) findViewById(R.id.btn_goB1);//找id为btn_openActivity的button
             btn_goB1.setOnClickListener(new OnClickListener() {//设置button点击监听

                 @Override
                 public void onClick(View v) {//onclick事件
                     // TODO Auto-generated method stub
                     Intent intent=new Intent();//初始化intent
                     intent.setClass(ActivityB2.this,MainActivity.class);//连接
                     startActivity(intent);//打开activity
                 }
             });

             btn_goB2=(Button) findViewById(R.id.btn_goB2);//找id为btn_openActivity的button
             btn_goB2.setOnClickListener(new OnClickListener() {//设置button点击监听

                 @Override
                 public void onClick(View v) {//onclick事件
                     // TODO Auto-generated method stub
                     Intent intent=new Intent();//初始化intent
                     intent.setClass(ActivityB2.this,ActivityB2.class);//连接
                     startActivity(intent);//打开activity
                 }
             });
         }
      @Override
     protected void onNewIntent(Intent intent) {
         // TODO Auto-generated method stub
         super.onNewIntent(intent);
         Toast.makeText(this, "onNewIntent", Toast.LENGTH_SHORT).show();;
     }
 }

/activityLaunchSingleTop/AndroidManifest.xml

 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="com.example.activityLaunchSingleTop"
     android:versionCode="1"
     android:versionName="1.0" >

     <uses-sdk
         android:minSdkVersion="8"
         android:targetSdkVersion="19" />

     <application
         android:allowBackup="true"
         android:icon="@drawable/ic_launcher"
         android:label="@string/app_name"
         android:theme="@style/AppTheme" >
         <activity
             android:name="activityLaunchSingleTop.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>

         <activity android:name="activityLaunchSingleTop.ActivityB2" android:launchMode="singleTop"></activity>
     </application>

 </manifest>

/activityLaunchSingleTop/res/layout/activity_main.xml

 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:orientation="vertical" >

     <TextView
         android:id="@+id/tV_B1"
         android:layout_width="match_parent"
         android:layout_height="96dp"
         android:text="@string/tV_B1"
         android:textAppearance="?android:attr/textAppearanceLarge" />

     <Button
         android:id="@+id/btn_goB1"
         android:layout_width="match_parent"
         android:layout_height="50dp"
         android:layout_weight="0.00"
         android:text="@string/btn_goB1" />

     <Button
         android:id="@+id/btn_goB2"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:text="@string/btn_goB2" />

 </LinearLayout>

/activityLaunchSingleTop/res/layout/activity_b2.xml

 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:orientation="vertical" >

     <TextView
         android:id="@+id/tV_B2"
         android:layout_width="match_parent"
         android:layout_height="96dp"
         android:text="@string/tV_B2"
         android:textAppearance="?android:attr/textAppearanceLarge" />

     <Button
         android:id="@+id/btn_goB1"
         android:layout_width="match_parent"
         android:layout_height="50dp"
         android:layout_weight="0.00"
         android:text="@string/btn_goB1" />

     <Button
         android:id="@+id/btn_goB2"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:text="@string/btn_goB2" />

 </LinearLayout>