设置与桌面相同的action和category 安卓系统桌面也是一个activity,安卓桌面的action和category是: <activity android:name="com.sxt.day04_07_twoaction.MainActivity" android:label="@string/app_name" > <intent-filter> <action android:name="android.intent.action.MAIN" />项目入口acticity <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> 给自己的acticity设置的和桌面一样,会弹出窗口选择是启动安卓系统桌面的activity还是我们自己的activity。
main.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical"> <Button android:id="@+id/btnHome" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="启动桌面Activity" /> </LinearLayout>
main.java
package com.sxt.day04_07_twoaction; import android.os.Bundle; import android.app.Activity; import android.content.Intent; import android.view.Menu; import android.view.View; import android.view.View.OnClickListener; public class MainActivity extends Activity implements OnClickListener{ @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); setListener(); } private void setListener() { findViewById(R.id.btnHome).setOnClickListener(this); } @Override public void onClick(View v) { Intent intent=new Intent(); switch (v.getId()) { case R.id.btnHome: intent.addCategory(Intent.CATEGORY_HOME); intent.setAction(Intent.ACTION_MAIN);//这里用常量,也可以写字符串 break; } startActivity(intent); } }
系统描述文件:
<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.sxt.day04_07_twoaction" android:versionCode="1" android:versionName="1.0" > <uses-sdk android:minSdkVersion="8" android:targetSdkVersion="18" /> <application android:allowBackup="true" android:icon="@drawable/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme" > <activity android:name="com.sxt.day04_07_twoaction.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="com.sxt.day04_07_twoaction.SecondActivity" //要启动的activity的java类 android:label="@string/title_activity_second" > <intent-filter> <action android:name="android.intent.action.MAIN"/> <category android:name="android.intent.category.DEFAULT"/>与桌面activity相同的时候也要加上这个,然后再设置一个category <category android:name="android.intent.category.HOME"/> </intent-filter> </activity> </application> </manifest>
SecondActivity.java
package com.sxt.day04_07_twoaction; import android.os.Bundle; import android.app.Activity; import android.util.Log; import android.view.Menu; public class SecondActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_second); //加载xml文件 Log.i("main","SecondActivity"); } }
SecondActivity.xml
<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=".SecondActivity" > <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/hello_world" /> </RelativeLayout>
效果: