1、activity_main.xml
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/activity_main" 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="example.com.myapplication.MainActivity"> <Button android:text="second" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="27dp" android:id="@+id/button" android:onClick="secondActivty" android:visibility="visible" android:layout_alignParentStart="true" /> <Button android:text="first" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_below="@+id/button" android:layout_alignParentStart="true" android:layout_marginTop="13dp" android:id="@+id/button2" android:onClick="firstyActivty" android:visibility="visible" /> </RelativeLayout>
2、MainActivity.java
package example.com.myapplication; import android.app.Activity; import android.content.Intent; import android.content.pm.ActivityInfo; import android.content.pm.PackageManager; import android.os.Bundle; import android.util.Log; import android.view.View; public class MainActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); try { ActivityInfo info = this.getPackageManager().getActivityInfo(getComponentName(), 0); Log.i("moyanyun", "taskId:" + getTaskId() + "; activityInfo:" + info.toString() + "\n"); } catch (PackageManager.NameNotFoundException e) { } } public void secondActivty(View v) { Intent intent = new Intent(MainActivity.this, SecondActivity.class); startActivity(intent); } public void firstyActivty(View v) { Intent intent = new Intent(MainActivity.this, MainActivity.class); startActivity(intent); } }
3、activity_second.xml
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/activity_second" 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="example.com.myapplication.SecondActivity"> <Button android:text="third" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_alignParentTop="true" android:layout_alignParentStart="true" android:id="@+id/button2" android:visibility="visible" android:onClick="thirdActivity" /> <Button android:text="first" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_alignParentStart="true" android:layout_marginTop="33dp" android:id="@+id/button5" android:visibility="visible" android:onClick="startFistActivity" /> </RelativeLayout>
4、SecondActivity.java
package example.com.myapplication; import android.app.Activity; import android.content.Intent; import android.content.pm.ActivityInfo; import android.content.pm.PackageManager; import android.os.Bundle; import android.util.Log; import android.view.View; public class SecondActivity extends Activity { /*TextView txv, txv2; ActivityInfo info;*/ @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_second); /*txv = findViewById(R.id.textView3); txv2 = findViewById(R.id.textView4);*/ try { ActivityInfo info = this.getPackageManager().getActivityInfo(getComponentName(), 0); Log.i("moyanyun", "taskId:" + getTaskId() + "; activityInfo:" + info.toString()); } catch (PackageManager.NameNotFoundException e) { } /*txv.setText(String.valueOf(taskId)); txv2.setText(info.toString());*/ } public void thirdActivity(View v) { Intent intent = new Intent(this, SecondActivity.class); startActivity(intent); } public void startFistActivity(View v) { Intent intent = new Intent(this, MainActivity.class); startActivity(intent); } }
5、AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="example.com.myapplication"> <!-- android:launchMode="singleInstance" android:launchMode="singleTask" android:launchMode="singleTop" android:launchMode="standard" --> <application android:allowBackup="true" android:icon="@mipmap/ic_launcher" android:label="@string/app_name" android:supportsRtl="true" android:theme="@style/AppTheme"> <activity android:name=".MainActivity" android:launchMode="standard" > <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> <activity android:name=".SecondActivity" android:label="@string/title_activity_second" /> </application> </manifest>
总结