Activity生命周期，状态保存恢复（经典）

一、整体框架

Activity生命周期，状态保存恢复（经典）_第1张图片

二、main.xml

<LinearLayout 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:orientation="vertical" ><Button        android:id="@+id/startPartActivity"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:text="startPartActivity" >    </Button>    <Button        android:id="@+id/startDialog"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:text="startDialog" >    </Button>    <EditText        android:id="@+id/et_input"        android:layout_width="match_parent"        android:layout_height="wrap_content"         /></LinearLayout>

三、part_activity.xml，这是一个悬浮Activity的布局。

<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"     android:layout_width="fill_parent"     android:layout_height="fill_parent">     <ImageView     android:id="@+id/iv_logo"     android:layout_width="wrap_content"     android:layout_height="wrap_content"     android:layout_alignParentTop="true"     android:src="@drawable/gesture1"     />     <TextView  android:layout_width="wrap_content" android:text="Hello Jltxgcy"     android:layout_height="wrap_content"     android:layout_below="@id/iv_logo"     android:textColor="@android:color/black"     /> </RelativeLayout>

四、AndroidManifest.xml，悬浮PartActivity需要设置其android:theme属性。

<manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.jltxgcy.lifecycledemo"    android:versionCode="1"    android:versionName="1.0" >    <uses-sdk        android:minSdkVersion="8"        android:targetSdkVersion="15" />    <application        android:icon="@drawable/ic_launcher"        android:label="LifecycleDemo" >        <activity            android:name=".MainActivity"            android:label="MainActivity" >            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>        <activity            android:name=".PartActivity"            android:theme="@android:style/Theme.Dialog" >        </activity>    </application></manifest>

五、MainActivity.java

package com.jltxgcy.lifecycledemo;import android.app.Activity;import android.app.AlertDialog;import android.content.DialogInterface;import android.content.Intent;import android.os.Bundle;import android.util.Log;import android.view.View;import android.view.View.OnClickListener;import android.widget.Toast;public class MainActivity extends Activity {public static final String TAG="jltxgcy";    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);        Log.d(TAG, "MainActivity onCreate");                findViewById(R.id.startPartActivity).setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {Intent intent = new Intent(MainActivity.this, PartActivity.class);startActivity(intent);}});                findViewById(R.id.startDialog).setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {final CharSequence[] items = {"Red", "Green", "Blue"};//调用dialogAlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);builder.setTitle("Pick a color");builder.setItems(items, new DialogInterface.OnClickListener() {    public void onClick(DialogInterface dialog, int item) {        Toast.makeText(getApplicationContext(), items[item], Toast.LENGTH_SHORT).show();    }});AlertDialog alert = builder.create();alert.show()  ;}});    }        @Override   protected void onStart() {   // TODO Auto-generated method stub   Log.d(TAG, "MainActivity onStart");   super.onStart();   }   @Override   protected void onResume() {   Log.d(TAG, "MainActivity onResume");   super.onResume();   }   @Override   protected void onPause() {   Log.d(TAG, "MainActivity onPause");   super.onPause();   }   @Override   protected void onStop() {   Log.d(TAG, "MainActivity onStop");   super.onStop();   }   @Override   protected void onDestroy() {   Log.d(TAG, "MainActivity onDestroy");   super.onDestroy();   }   @Override   protected void onRestart() {   Log.d(TAG, "MainActivity onRestart");   super.onRestart();   }      @Overrideprotected void onSaveInstanceState(Bundle outState) {super.onSaveInstanceState(outState);Log.d("gcyjltx", "onSaveInstanceState");}}

六、PartActivity.java 悬浮Activity

package com.jltxgcy.lifecycledemo;import android.app.Activity;import android.os.Bundle;import android.view.Window;public class PartActivity extends Activity {@Overrideprotected void onCreate(Bundle savedInstanceState) {// TODO Auto-generated method stubsuper.onCreate(savedInstanceState);requestWindowFeature(Window.FEATURE_NO_TITLE)  ;setContentView(R.layout.part_activity)  ;}}

七、生命周期测试

当第一次进入MainActivity，结果显示如下：