安卓-生命周期
实验目的:
生成运行第一个Android程序,熟悉了解Android手机开发平台的基本构成和使用方法,熟悉Android应用程序项目的基本文件目录结构,了解开发环境提供的各种工具的基本用法。
在Activity中重载下9种事件函数,在调用不同函数时使用LogCat在Eclipse的控制台中输出调用日志。掌握Activity在启动、停止和销毁等不同阶段,9种重载函数的调用顺序,并掌握Android调试工具LogCat的使用方法
1 package com.example.administrator.myapplication; 2 3 import android.support.v7.app.AppCompatActivity; 4 import android.os.Bundle; 5 import android.util.Log; 6 7 public class MainActivity extends AppCompatActivity { 8 9 private static String TAG = "LIFECYCLE"; 10 11 @Override 12 protected void onCreate(Bundle savedInstanceState) { 13 super.onCreate(savedInstanceState); 14 setContentView(R.layout.activity_main); 15 Log.i(TAG, "onCreate"); 16 } 17 18 @Override 19 protected void onStart() { 20 super.onStart(); 21 Log.i(TAG, "onStart"); 22 } 23 24 @Override 25 protected void onResume() { 26 super.onResume(); 27 Log.i(TAG, "onResume"); 28 } 29 30 @Override 31 protected void onRestart() { 32 super.onRestart(); 33 Log.i(TAG, "onRestart"); 34 } 35 36 @Override 37 protected void onPause() { 38 super.onPause(); 39 Log.i(TAG, "onPause"); 40 } 41 42 @Override 43 protected void onStop() { 44 super.onStop(); 45 Log.i(TAG, "onStop"); 46 } 47 48 @Override 49 protected void onDestroy() { 50 super.onDestroy(); 51 Log.i(TAG, "onDestroy"); 52 } 53 54 @Override 55 protected void onSaveInstanceState(Bundle outState) { 56 super.onSaveInstanceState(outState); 57 Log.i(TAG, "onSaveInstanceState"); 58 } 59 60 @Override 61 protected void onRestoreInstanceState(Bundle savedInstanceState) { 62 super.onRestoreInstanceState(savedInstanceState); 63 Log.i(TAG, "onRestoreInstanceState"); 64 } 65 66 }
1 <?xml version="1.0" encoding="utf-8"?> 2 <android.support.constraint.ConstraintLayout 3 xmlns:android="http://schemas.android.com/apk/res/android" 4 xmlns:tools="http://schemas.android.com/tools" 5 xmlns:app="http://schemas.android.com/apk/res-auto" 6 android:layout_width="match_parent" 7 android:layout_height="match_parent" 8 tools:context="com.example.administrator.myapplication.MainActivity"> 9 10 <TextView 11 android:layout_width="wrap_content" 12 android:layout_height="wrap_content" 13 android:text="Hello World!" 14 app:layout_constraintBottom_toBottomOf="parent" 15 app:layout_constraintLeft_toLeftOf="parent" 16 app:layout_constraintRight_toRightOf="parent" 17 app:layout_constraintTop_toTopOf="parent" /> 18 19 </android.support.constraint.ConstraintLayout>
1 <?xml version="1.0" encoding="utf-8"?> 2 <manifest xmlns:android="http://schemas.android.com/apk/res/android" 3 package="com.example.administrator.myapplication" > 4 5 <application 6 android:allowBackup="true" 7 android:icon="@mipmap/ic_launcher" 8 android:label="@string/app_name" 9 android:roundIcon="@mipmap/ic_launcher_round" 10 android:supportsRtl="true" 11 android:theme="@style/AppTheme" > 12 <activity android:name=".MainActivity" > 13 <intent-filter> 14 <action android:name="android.intent.action.MAIN" /> 15 16 <category android:name="android.intent.category.LAUNCHER" /> 17 </intent-filter> 18 </activity> 19 </application> 20 21 </manifest>