Android教程網
設為首頁|加入收藏
  1. 首頁
  2. Android 技術
  3. Android 手機
  4. Android 系統教程
  5. Android 游戲
 Android教程網 >> Android技術 >> 關於Android編程 >> Android Activity各啟動模式的差異

Android Activity各啟動模式的差異

編輯：關於Android編程

Android Activity各啟動模式的差異

Activity共有四種啟動模式：standard，singleTop，singleTask，singleInstance

 

為了方便描述和理解，布局文件、Manifest文件和各個java文件如下：

AndoirdManifest文件

\\
View Code

　　4個Activity分別對應一種啟動模式：

　　　　MainActivity ----> standard (默認模式，寫不寫都可以)

　　　　SecondActivity ----> singleTop

　　　　ThirdActivty ----> singleTask

　　　　FourActivity ----> singleInstance

布局文件 activity_main.xml

\\
View Code

MainActivity.java

\\ 
package com.example.activitylaunchmode;

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

public class MainActivity extends Activity implements OnClickListener{

    private static final String TAG = "MainActivity";
    TextView tv;
    Button ButtonOne;
    Button ButtonTwo;
    Button ButtonThree;
    Button ButtonFour;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tv = (TextView) findViewById(R.id.mTextView);
        tv.setText("MainActivity");
        ButtonOne = (Button) findViewById(R.id.buttonOne);
        ButtonOne.setOnClickListener(this);
        ButtonTwo = (Button) findViewById(R.id.buttonTwo);
        ButtonTwo.setOnClickListener(this);
        ButtonThree = (Button) findViewById(R.id.buttonThree);
        ButtonThree.setOnClickListener(this);
        ButtonFour = (Button) findViewById(R.id.buttonFour);
        ButtonFour.setOnClickListener(this);
    }
    
    @Override
    protected void onNewIntent(Intent intent) {
        // TODO Auto-generated method stub
        super.onNewIntent(intent);
        Log.d(TAG, "onNewIntent");
    }

    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub
        switch (v.getId()) {
        case R.id.buttonOne:
            Intent mainIntent = new Intent(this,MainActivity.class);
            startActivity(mainIntent);
            break;
        case R.id.buttonTwo:
            Intent secondIntent = new Intent(this,SecondActivity.class);
            startActivity(secondIntent);
            break;
        case R.id.buttonThree:
            Intent ThirdIntent = new Intent(this,ThirdActivity.class);
            startActivity(ThirdIntent);
            break;
        case R.id.buttonFour:
            Intent FourIntent = new Intent(this,FourActivity.class);
            startActivity(FourIntent);
            break;
        }
    }
}
View Code

SecondActivity.java

\\ 
package com.example.activitylaunchmode;

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

public class SecondActivity extends Activity implements OnClickListener {
    
    private static final String TAG = "SecondActivity";
    TextView tv;
    Button ButtonOne;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tv = (TextView) findViewById(R.id.mTextView);
        tv.setText("SecondActivity");
        ButtonOne = (Button) findViewById(R.id.buttonOne);
        ButtonOne.setOnClickListener(this);
    }

    @Override
    protected void onNewIntent(Intent intent) {
        // TODO Auto-generated method stub
        super.onNewIntent(intent);
        Log.d(TAG, "onNewIntent");
    }

    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub
        switch (v.getId()) {
        case R.id.buttonOne:
            Intent secondIntent = new Intent(this,SecondActivity.class);
            startActivity(secondIntent);
            break;
        }
    }
}
View Code

ThirdActivity.java

\\ 
package com.example.activitylaunchmode;

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

public class ThirdActivity extends Activity implements OnClickListener {

    private static final String TAG = "ThirdActivity";
    TextView tv;
    Button ButtonOne;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tv = (TextView) findViewById(R.id.mTextView);
        tv.setText("ThirdActivity");
        ButtonOne = (Button) findViewById(R.id.buttonOne);
        ButtonOne.setOnClickListener(this);
    }
    
    @Override
    protected void onNewIntent(Intent intent) {
        // TODO Auto-generated method stub
        super.onNewIntent(intent);
        Log.d(TAG, "onNewIntent");
    }

    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub
        switch (v.getId()) {
        case R.id.buttonOne:
            Intent mainIntent = new Intent(this,MainActivity.class);
            startActivity(mainIntent);
            break;

        default:
            break;
        }
    }
    
}
View Code

FourActivity.java

\\ 
package com.example.activitylaunchmode;

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

public class FourActivity extends Activity implements OnClickListener {

    private static final String TAG = "FourActivity";
    TextView tv;
    Button ButtonOne;
    Button ButtonTwo;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tv = (TextView) findViewById(R.id.mTextView);
        tv.setText("FourActivity");
        ButtonOne = (Button) findViewById(R.id.buttonOne);
        ButtonOne.setOnClickListener(this);
    }
    
    @Override
    protected void onNewIntent(Intent intent) {
        // TODO Auto-generated method stub
        super.onNewIntent(intent);
        Log.d(TAG, "onNewIntent");
    }

    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub
        switch (v.getId()) {
        case R.id.buttonOne:
            Intent MainIntent = new Intent(this,MainActivity.class);
            startActivity(MainIntent);
            break;

        case R.id.buttonFour:
            Intent FourIntent = new Intent(this,FourActivity.class);
            startActivity(FourIntent);
        default:
            break;
        }
    }
    
}
View Code 各個啟動模式差異探究：

　　1）standard: 默認模式，每啟動一個activity都會在Task中創建一個，back鍵會依次從棧中退出

　　　　MainActivity的啟動模式是standard, 點擊Button1,會再啟動一個MainActivity.

　　　　通過adb shell dumpsys activity命令， 我們能看到在Task中存在兩個MainActivity.

    Task id #48
      TaskRecord{2cfa2efd #48 A=com.example.activitylaunchmode U=0 sz=2}
      Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x30200000 cmp=com.example.activitylaunchmode/.MainActivity }
        Hist #1: ActivityRecord{37783c3a u0 com.example.activitylaunchmode/.MainActivity t48}
          Intent { cmp=com.example.activitylaunchmode/.MainActivity }
          ProcessRecord{358547f2 29163:com.example.activitylaunchmode/u0a134}
        Hist #0: ActivityRecord{363c8000 u0 com.example.activitylaunchmode/.MainActivity t48}
          Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x30200000 cmp=com.example.activitylaunchmode/.MainActivity bnds=[801,812][1047,1060] }
          ProcessRecord{358547f2 29163:com.example.activitylaunchmode/u0a134}

    Running activities (most recent first):
      TaskRecord{2cfa2efd #48 A=com.example.activitylaunchmode U=0 sz=2}
        Run #1: ActivityRecord{37783c3a u0 com.example.activitylaunchmode/.MainActivity t48}
        Run #0: ActivityRecord{363c8000 u0 com.example.activitylaunchmode/.MainActivity t48}

　　

　　2）singleTop：如果要啟動的Activity在棧頂，則不會重新創建

　　　 SecondActivity的啟動模式是singleTop, 點擊MainActivity中的Button2,會創建一個SecondActivity,再點擊SecondActivity中的Button1,會重新啟動　SecondActivity.

　　　　通過adb命令，我們可以看到，Task中只有MainActivity和SecondActivity兩個Activity,第二次點擊並沒有重新創建。從log中，我們可以看到，第二次點擊啟動SecondActivity,只是調用了前一個SecondActivity的onNewIntent方法。

    Task id #51
      TaskRecord{fb41e01 #51 A=com.example.activitylaunchmode U=0 sz=2}
      Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x30200000 cmp=com.example.activitylaunchmode/.MainActivity }
        Hist #1: ActivityRecord{1ea62f6c u0 com.example.activitylaunchmode/.SecondActivity t51}
          Intent { cmp=com.example.activitylaunchmode/.SecondActivity }
          ProcessRecord{69b44a6 30061:com.example.activitylaunchmode/u0a134}
        Hist #0: ActivityRecord{27f7bb0a u0 com.example.activitylaunchmode/.MainActivity t51}
          Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x30200000 cmp=com.example.activitylaunchmode/.MainActivity bnds=[801,812][1047,1060] }
          ProcessRecord{69b44a6 30061:com.example.activitylaunchmode/u0a134}

    Running activities (most recent first):
      TaskRecord{fb41e01 #51 A=com.example.activitylaunchmode U=0 sz=2}
        Run #1: ActivityRecord{1ea62f6c u0 com.example.activitylaunchmode/.SecondActivity t51}
        Run #0: ActivityRecord{27f7bb0a u0 com.example.activitylaunchmode/.MainActivity t51}

　　

　　3）singleTask: 任務棧中沒有這個Activity,則會在任務棧中創建一個實例，如果任務棧中已經存在，則會將任務棧中的此activity之上的activity全部出棧

　　　　ThirdActivity的啟動模式是singleTask, 點擊MainActivity中的Button3,啟動ThirdActivity,再點擊ThirdActivity中的Button1,啟動MainActivity，此時的Activity的堆棧信息如下：

    Task id #52
      TaskRecord{147eed75 #52 A=com.example.activitylaunchmode U=0 sz=3}
      Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x30200000 cmp=com.example.activitylaunchmode/.MainActivity }
        Hist #2: ActivityRecord{2bf26a69 u0 com.example.activitylaunchmode/.MainActivity t52}
          Intent { cmp=com.example.activitylaunchmode/.MainActivity }
          ProcessRecord{3e2f10a 30540:com.example.activitylaunchmode/u0a134}
        Hist #1: ActivityRecord{147e2631 u0 com.example.activitylaunchmode/.ThirdActivity t52}
          Intent { flg=0x10000000 cmp=com.example.activitylaunchmode/.ThirdActivity }
          ProcessRecord{3e2f10a 30540:com.example.activitylaunchmode/u0a134}
        Hist #0: ActivityRecord{4e87389 u0 com.example.activitylaunchmode/.MainActivity t52}
          Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x30200000 cmp=com.example.activitylaunchmode/.MainActivity bnds=[801,812][1047,1060] }
          ProcessRecord{3e2f10a 30540:com.example.activitylaunchmode/u0a134}

    Running activities (most recent first):
      TaskRecord{147eed75 #52 A=com.example.activitylaunchmode U=0 sz=3}
        Run #2: ActivityRecord{2bf26a69 u0 com.example.activitylaunchmode/.MainActivity t52}
        Run #1: ActivityRecord{147e2631 u0 com.example.activitylaunchmode/.ThirdActivity t52}
        Run #0: ActivityRecord{4e87389 u0 com.example.activitylaunchmode/.MainActivity t52}

　　　 這個也說明了standard啟動模式會重新創建一個Activity.

　　　 然後再點擊MainActivity中的Button3，啟動ThirdActivity,通過adb命令看到的如下：　

    Task id #53
      TaskRecord{2553d3b2 #53 A=com.example.activitylaunchmode U=0 sz=2}
      Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x30200000 cmp=com.example.activitylaunchmode/.MainActivity }
        Hist #1: ActivityRecord{33f3f7cd u0 com.example.activitylaunchmode/.ThirdActivity t53}
          Intent { flg=0x10000000 cmp=com.example.activitylaunchmode/.ThirdActivity }
          ProcessRecord{1cdd8f03 30924:com.example.activitylaunchmode/u0a134}
        Hist #0: ActivityRecord{e5f9ea5 u0 com.example.activitylaunchmode/.MainActivity t53}
          Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x30200000 cmp=com.example.activitylaunchmode/.MainActivity bnds=[801,812][1047,1060] }
          ProcessRecord{1cdd8f03 30924:com.example.activitylaunchmode/u0a134}

    Running activities (most recent first):
      TaskRecord{2553d3b2 #53 A=com.example.activitylaunchmode U=0 sz=2}
        Run #1: ActivityRecord{33f3f7cd u0 com.example.activitylaunchmode/.ThirdActivity t53}
        Run #0: ActivityRecord{e5f9ea5 u0 com.example.activitylaunchmode/.MainActivity t53}

　　　　 能看到Task中現在只有兩個Activity,ThirdActivity並沒有重新創建，靠後的一個MainActivity也被彈出棧，從log也能看出調用了onNewIntent方法，

　　

　　4）singleInstance: 只有一個實例，運行於獨立的task，啟動此Activity的時候如果已經創建，則不會重新創建

　　　　FourActivity的啟動模式是singleInstance,點擊MainActivity中的Button4，會啟動FourActivity

　　　　通過adb shell dumpsys activity命令，我們能看到兩個Activity在不同的Task中，　　　　

    Task id #55
      TaskRecord{11be8b0d #55 A=com.example.activitylaunchmode U=0 sz=1}
      Intent { flg=0x10000000 cmp=com.example.activitylaunchmode/.FourActivity }
        Hist #0: ActivityRecord{1cd2b9e5 u0 com.example.activitylaunchmode/.FourActivity t55}
          Intent { flg=0x10000000 cmp=com.example.activitylaunchmode/.FourActivity }
          ProcessRecord{358d5ac2 31514:com.example.activitylaunchmode/u0a134}
    Task id #54
      TaskRecord{12e2f0d3 #54 A=com.example.activitylaunchmode U=0 sz=1}
      Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x30200000 cmp=com.example.activitylaunchmode/.MainActivity }
        Hist #0: ActivityRecord{374dcd03 u0 com.example.activitylaunchmode/.MainActivity t54}
          Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x30200000 cmp=com.example.activitylaunchmode/.MainActivity bnds=[801,812][1047,1060] }
          ProcessRecord{358d5ac2 31514:com.example.activitylaunchmode/u0a134}

    Running activities (most recent first):
      TaskRecord{11be8b0d #55 A=com.example.activitylaunchmode U=0 sz=1}
        Run #1: ActivityRecord{1cd2b9e5 u0 com.example.activitylaunchmode/.FourActivity t55}
      TaskRecord{12e2f0d3 #54 A=com.example.activitylaunchmode U=0 sz=1}
        Run #0: ActivityRecord{374dcd03 u0 com.example.activitylaunchmode/.MainActivity t54}

　　　　如果再點擊FourActivity中的Button4,也不會重新創建，從log可以看出，會調用onNewIntent方法，這裡就不在貼activity的信息。

 

　　　 adb shell dumpsys activity activities 也可以看到Task中各個activity的 launchMode.

 

 

　　　　

  1. 上一頁:
  2. 下一頁:
關於Android編程
Android編程入門Android技術基礎Android資訊關於Android編程Android開發Android開發環境Android開發實例
相關文章
熱門文章
圖像處理的小demo——Android Android開發之SQLite的使用方法 Android 利用ViewPager實現圖片可以左右循環滑動效果附代碼下載 Android中Fiddler的使用技巧 Android開發之設置鈴聲 Android Drawerlayout側拉欄事件傳遞問題的解決方法
Android應用程序中讀寫txt文本文件的基本方法講解

最終效果圖，點擊save會保存到文件中，點擊show會從文件中讀取出內容
Material Design Support 8大控件介紹

TextInputLayout顯示提示信息可以通過調用setError(
最常用和最難用的Android控件ListView

ListView允許用戶通過手指上下滑動的方式將屏幕外的數據滾動到屏幕內
詳解Android使用OKHttp3實現下載(斷點續傳、顯示進度)

OKHttp3是如今非常流行的Android網絡請求框架,那麼如何利用A
閱讀排行版
Copyright © Android教程網 All Rights Reserved