Android快速开发

在这里，你只需要复制、粘贴和稍微加一点修改即可。适用于有Android基础的同学，并且又不愿意做重复工作的同学

• 涉及到的点有
  
  • 从字符XML中拿数组
  • ListView适配器
  • 去除标题栏
  • 发送消息到通知栏
  • 使用Intent 传递对象
  • Spinner控件
  • 具体项目的DBHelper
  • 具体项目的DB
  • 全屏模式
  • 圆角按钮实现
  • 实现按钮被点击的效果
  • 覆写系统方法
  • 知晓当前活动
  • 活动管理器
  • 自定义控件
  • 网络监测
  • 数据持久化方案
  • SQLiteDatabase事务
  • 自定义内容提供器
  • SurfaceView 的基本框架

1.学习安卓的以前都学过web开发

2.

// 从字符XML中拿数组String[] apps = getResources().getStringArray(R.array.apps);

3.

  // ListView适配器     class ListViewAdapter extends BaseAdapter {          @Override          public int getCount() {               return appList.size();          }          @Override          public App getItem(int position) {               return appList.get(position);          }          @Override          public long getItemId(int position) {               return position;          }          @Override          public View getView(int position, View convertView, ViewGroup parent) {               ViewHolder holder = null;               if (convertView == null) {                    // 获取ListViewItem的布局                    convertView = View.inflate(MainActivity.this,R.layout.activity_main_item, null);                    holder = new ViewHolder();                    // 获取子项中的具体布局                    holder.image = (ImageView) convertView.findViewById(R.id.iv_list);                    holder.text = (TextView) convertView.findViewById(R.id.tv_list);                    convertView.setTag(holder);               } else {                    holder = (ViewHolder) convertView.getTag();               }               // 设置相关信息               holder.image.setImageResource(appList.get(position).getPicId());               holder.text.setText(appList.get(position).getAppName());               return convertView;          }          class ViewHolder {               private ImageView image;               private TextView text;          }     }

4.去除标题栏

(1)requestWindowFeature(Window.FEATURE_NO_TITLE);(2)在values文件夹下面的styles.xml文件中添加一个样式：<style name="notitle">                       <item name="android:windowNoTitle">true</item>    </style>然后在AndroidManifest.xml文件中的<application>标签中添加一个android:theme 属性即可.例如：<application                  android:allowBackup="true"                  android:icon="@drawable/ic_launcher"                 android:label="@string/app_name"    android:theme="@style/notitle" >

5.发送消息到通知栏

//启动目标Activity的Intent对象          Intent intent = new Intent(UserActivity.this, Welcome.class);          //pengding: 即将          PendingIntent pendIntent =PendingIntent.getActivity(UserActivity.this, 0, intent, 0);          //实例化通知实例          Notification notif= new Notification(R.drawable.welcome, "Hello,Lady or Gentleman!!Click me!!",System.currentTimeMillis());          notif.defaults=Notification.DEFAULT_SOUND;//声音          //拉开之后显示的信息          notif.setLatestEventInfo(UserActivity.this, "Hello", "Hello,Thank you for using app", pendIntent);          //通知管理器  管理通知          NotificationManager manager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);          //发送通知     manager.notify(1, notif);

6.使用Intent 传递对象

//传递               Intent intent = new Intent();               intent.setClass(UserActivity.this,UserInfo.class);               Bundle bundle = new Bundle();               bundle.putSerializable("user", user);               intent.putExtras(bundle);          this.startActivity(intent);

7.Spinner控件

//当点击登录时才会获取，所以不用放在选项改变的方法中，不用时刻检测，只需要在点击登录时获取就好          String loc = spLoc.getSelectedItem().toString();

8.具体项目的DBHelper

public class CoolWeatherOpenHelper extends SQLiteOpenHelper {     /**     *     Province建表语句     */     public static final String CREATE_PROVINCE="create table Province (" +               "id integer primary key autoincrement," +               "province_name text," +               "province_code text)";     /**     *     City建表语句     */     public static final String CREATE_CITY="create table City (" +               "id integer primary key autoincrement," +               "city_name text," +               "city_code text," +               "province_id integer)";     /**     *     County建表语句     */     public static final String CREATE_COUNTY="create table County (" +               "id integer primary key autoincrement," +               "county_name text," +               "county_code text," +               "city_id integer)";     public CoolWeatherOpenHelper(Context context, String name,               CursorFactory factory, int version) {          super(context, name, factory, version);     }     @Override     public void onCreate(SQLiteDatabase db) {          db.execSQL(CREATE_PROVINCE);//创建Province表          db.execSQL(CREATE_CITY);//创建City表          db.execSQL(CREATE_COUNTY);//创建County表     }     @Override     public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {          // TODO Auto-generated method stub     }}

9.具体项目的DB

public class CoolWeatherDB {     /**     * 数据库名     */     public static final String DB_NAME="cool_weather";     /**     * 数据库版本     */     public static final int VERSION=1;     private static CoolWeatherDB coolWeatherDB;//采用单例模式     private SQLiteDatabase db;     /**     * 将构造方法私有化     */     private CoolWeatherDB(Context context){          CoolWeatherOpenHelper dbHelper = new CoolWeatherOpenHelper(context, DB_NAME, null, VERSION);          db = dbHelper.getWritableDatabase();     }     /**     * 获取CoolWeatherDB的实例     */     public synchronized static CoolWeatherDB getInstance(Context context){          if(coolWeatherDB == null){               coolWeatherDB = new CoolWeatherDB(context);          }          return coolWeatherDB;     }     /**     * 将Province实例存储到数据库     */     public void saveProvince(Province province){          if(province != null){               ContentValues values = new ContentValues();               values.put("province_name", province.getProvinceName());               values.put("province_code", province.getProvinceCode());               db.insert("Province", null, values);          }     }     /**     * 从数据库读取全国所有的省份信息     */     public List<Province> loadProvinces(){          List<Province> list = new ArrayList<Province>();          Cursor cursor =db.query("Province", null, null, null, null, null, null);          if(cursor.moveToFirst()){               do{                    Province province = new Province();                    province.setId(cursor.getInt(cursor.getColumnIndex("id")));                    province.setProvinceName(cursor.getString(cursor.getColumnIndex("province_name")));                    province.setProvinceCode(cursor.getString(cursor.getColumnIndex("province_code")));                    list.add(province);               }while(cursor.moveToNext());               if(cursor != null){                    cursor.close();               }          }          if(cursor != null){               cursor.close();          }          return list;     }}

10.全屏模式(但是标题栏还在,标题栏可去)

getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);

11.圆角按钮实现：

首先写一个XML，专门处理按钮图形的，比如叫做shape.xml,就先放在drawable文件夹下面吧.shape.xml:<?xml version="1.0" encoding="UTF-8"?><shape    xmlns:android="http://schemas.android.com/apk/res/android"    android:shape="rectangle">    <!-- 填充的颜色 -->    <solid android:color="#FFFFFF" />    <!-- 设置按钮的四个角为弧形 -->    <!-- android:radius 弧形的半径 -->    <corners android:radius="5dip" /><!-- padding：Button里面的文字与Button边界的间隔 --><padding   android:left="10dp"   android:top="10dp"   android:right="10dp"   android:bottom="10dp"/></shape>接下来，在布局文件中引用就OK 了.<Button        .......    android:background="@drawable/shape"  />

12.实现按钮被点击的效果

首先写btn_selector.xml文件<?xml version="1.0" encoding="utf-8"?><selector xmlns:android="http://schemas.android.com/apk/res/android">             <item android:state_pressed="false"              android:drawable="@drawable/coolweather"/>              <item android:state_pressed="true"              android:drawable="@drawable/fiftyfour_backgroun"/></selector>在布局文件中.<Button        .......    android:background="@drawable/btn_selector"  />

13.如果在覆写系统方法的时候，报这个错误：

08-25 10:36:28.234: E/AndroidRuntime(5066):java.lang.RuntimeException:Unable to resume activity {com.example.androidvideoplay/com.example.androidvideoplay.MainActivity}: android.app.SuperNotCalledException: Activity {com.example.androidvideoplay/com.example.androidvideoplay.MainActivity} did not call through to super.onResume()原因在红色字体，已经很清楚的告诉你了，你没有调用系统的super.相应的方法

14.当SurfaceView所在的Activity离开了前台之后，SurfaceView会被摧毁，当Activity有重新回到前台时，SurfaceView会被重新创建，创建是在onResume（）方法之后

15.知晓当前是哪一个活动，让此活动成为其他活动的父类

/*** 技巧：知晓当前是哪一个活动，让此活动成为其他活动的父类   FirstActivity extends BaseActivity 、FirstActivity extends BaseActivity ......*/public class BaseActivity extends Activity {     @Override     protected void onCreate(Bundle savedInstanceState) {          super.onCreate(savedInstanceState);          Log.i("BaseActivity",getClass().getSimpleName());          setContentView(R.layout.activity_base);     }     @Override     public boolean onCreateOptionsMenu(Menu menu) {          // Inflate the menu; this adds items to the action bar if it is present.          getMenuInflater().inflate(R.menu.activity_base, menu);          return true;     }}

16.

/***类描述： 活动管理器*/public class ActivityCollector {     public static List<Activity> activities = new ArrayList<Activity>();     public static void addActivity(Activity activity){          activities.add(activity);     }     public static void removeActivity(Activity activity){          activities.remove(activity);     }     public static void finishAll(){          for(Activity activity : activities){               if(!activity.isFinishing()){                    activity.finish();               }          }     }}

17.创建自定义控件

/**** 类描述：自定义的标题控件*/public class TitleLayout extends LinearLayout {     public TitleLayout(Context context, AttributeSet attrs) {          super(context, attrs);          // 动态加载布局文件          LayoutInflater.from(context).inflate(R.layout.title, this);          // 设定按钮监听事件          findViewById(R.id.title_back).setOnClickListener(new OnClickListener() {               @Override               public void onClick(View v) {                    //结束当前的Activity                    ((Activity) getContext()).finish();               }          });          findViewById(R.id.title_edit).setOnClickListener(new OnClickListener() {               @Override               public void onClick(View v) {                    //在自定义控件里面错误的写法：Toast.makeText(this, "编辑按钮", Toast.LENGTH_LONG).show();                    Toast.makeText(getContext(), "编辑按钮", Toast.LENGTH_LONG).show();               }          });     }}

18.监测网络是否可用

ConnectivityManager connectivityManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);               NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();               if(networkInfo != null && networkInfo.isAvailable()){                    Toast.makeText(context, "网络可用", Toast.LENGTH_SHORT).show();               }else{                    Toast.makeText(context, "网络不可用", Toast.LENGTH_SHORT).show();          }需要在配置文件当中加入相应的权限：<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />

19.数据持久化方案
a)使用文件
i.将数据存储到文件中

String fileName = "usefile.txt";                    String content = "我是要存储的字符串";                    try {                         FileOutputStream fos = openFileOutput(fileName,                                   Context.MODE_PRIVATE);                         fos.write(content.getBytes());                         fos.close();                    } catch (IOException e) {                         e.printStackTrace();          }

ii.从文件中读取数据

String content = null;                   try {                            String fileName = "usefile.txt";                      FileInputStream fis = openFileInput(fileName);                       ByteArrayOutputStream baos = new ByteArrayOutputStream();                       byte[] buffer = new byte[1024];                       int len = 0;                       while ((len = fis.read(buffer)) != -1) {                           baos.write(buffer, 0, len);                       }                       content = baos.toString();                       Toast.makeText(MainActivity.this, content, Toast.LENGTH_LONG).show();                      fis.close();                       baos.close();                   } catch (Exception e) {                       e.printStackTrace();     }

b) SharedPreferences存储
i.获取 SharedPreferences 对象的三种方式
1).Context的getSharedPreferences();
2).Activity的getPreferences();
3).PreferenceManager 的 getDefaultSharedPreferences();
Demo:
存数据：

SharedPreferences sharedPreferences = getSharedPreferences("data",MODE_PRIVATE);                    Editor edit = sharedPreferences.edit();                    edit.putString("name", "杨润康");                    edit.putInt("age", 20);     edit.commit();

读取数据:

SharedPreferences sharedPreferences = getSharedPreferences("data",MODE_PRIVATE);                    String name = sharedPreferences.getString("name", "null");                    int age = sharedPreferences.getInt("age", 0);Toast.makeText(MainActivity.this, name+age, Toast.LENGTH_LONG).show();

20.SQLiteDatabase使用事务[简单点，就是加三行事务的代码，其余的都一样]

  SQLiteDatabase db = databaseHelper.getReadableDatabase();                    db.beginTransaction();//开启事务                    try {                         db.delete("Book", null, null);//第一个操作                         /*if(true){//模拟故障，手动抛出异常                              throw new NullPointerException();                         }*/                         ContentValues values = new ContentValues();                         values.put("author", "blatran");                         values.put("price", "300");                         values.put("pages", "199");                         values.put("name", "yangrunkangtran");                         db.insert("Book", null, values);//第二个操作                         db.setTransactionSuccessful();//事务已经执行成功                    } catch (Exception e) {                         e.printStackTrace();                    }finally{                         db.endTransaction();//结束事务                    }

21.完整的自定义内容提供器

/*** 类描述：自定义的内容提供者*/public class MyProvider extends ContentProvider {     public static final int TABLE1_DIR = 0;     public static final int TABLE1_ITEM = 1;     public static final int TABLE2_DIR = 2;     public static final int TABLE2_ITEM = 3;     public static UriMatcher uriMatcher;     static {          uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);          uriMatcher.addURI("com.android_3200_contentresolver.provider",                    "table1", TABLE1_DIR);          uriMatcher.addURI("com.android_3200_contentresolver.provider",                    "table1/#", TABLE1_ITEM);          uriMatcher.addURI("com.android_3200_contentresolver.provider",                    "table2", TABLE2_DIR);          uriMatcher.addURI("com.android_3200_contentresolver.provider",                    "table2/#", TABLE2_ITEM);     }     @Override     public boolean onCreate() {          return false;     }     @Override     public Cursor query(Uri uri, String[] projection, String selection,               String[] selectionArgs, String sortOrder) {          switch (uriMatcher.match(uri)) {          case TABLE1_DIR:               //查询table1表中的所有数据               break;          case TABLE1_ITEM:               //查询table1表中的单条数据               break;          case TABLE2_DIR:               //查询table2表中的所有数据               break;          case TABLE2_ITEM:               //查询table2表中的单条数据               break;          default:               break;          }          return null;     }     @Override     public String getType(Uri uri) {          switch (uriMatcher.match(uri)) {          case TABLE1_DIR:               //查询table1表中的所有数据               return "vnd.android.cursor.dir/vnd.com.android_3200_contentresolver.provider.table1";          case TABLE1_ITEM:               //查询table1表中的单条数据               return "vnd.android.cursor.item/vnd.com.android_3200_contentresolver.provider.table1";          case TABLE2_DIR:               //查询table2表中的所有数据               return "vnd.android.cursor.dir/vnd.com.android_3200_contentresolver.provider.table2";          case TABLE2_ITEM:               //查询table2表中的单条数据               return "vnd.android.cursor.item/vnd.com.android_3200_contentresolver.provider.table2";          default:               break;          }          return null;     }     @Override     public Uri insert(Uri uri, ContentValues values) {          return null;     }     @Override     public int delete(Uri uri, String selection, String[] selectionArgs) {          return 0;     }     @Override     public int update(Uri uri, ContentValues values, String selection,               String[] selectionArgs) {          return 0;     }}

内容提供器的具体案例

public class DatabaseProvider extends ContentProvider {     public static final int BOOK_DIR = 0;     public static final int BOOK_ITEM = 1;     public static final int CATEGORY_DIR = 2;     public static final int CATEGORY_ITEM = 3;     private static final String AUTHORITY = "com.android_3100_androidpersistence.provider";     public static UriMatcher uriMatcher;     private MyDatabaseHelper dbHelper;     static {          uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);          uriMatcher.addURI(AUTHORITY, "bool", BOOK_DIR);          uriMatcher.addURI(AUTHORITY, "book/#", BOOK_ITEM);          uriMatcher.addURI(AUTHORITY, "category", CATEGORY_DIR);          uriMatcher.addURI(AUTHORITY, "category/#", CATEGORY_ITEM);     }     @Override     public boolean onCreate() {          dbHelper = new MyDatabaseHelper(getContext(), "BookStore.db", null, 2);          return true;     }     @Override     public Cursor query(Uri uri, String[] projection, String selection,               String[] selectionArgs, String sortOrder) {          // 查询数据          SQLiteDatabase db = dbHelper.getReadableDatabase();          Cursor query = null;          switch (uriMatcher.match(uri)) {          case BOOK_DIR:               query = db.query("Book", null, null, null, null, null, null);               break;          case BOOK_ITEM:               String bookId = uri.getPathSegments().get(1);               query = db.query("Book", null, "id=?", new String[] { bookId },null, null, sortOrder);               break;          case CATEGORY_DIR:               query = db.query("Category", null, null, null, null, null, null);               break;          case CATEGORY_ITEM:               String categoryId = uri.getPathSegments().get(1);               query = db.query("Category", null, "id=?",new String[] { categoryId }, null, null, sortOrder);               break;          default:               break;          }          return query;     }     @Override     public String getType(Uri uri) {          switch (uriMatcher.match(uri)) {          case BOOK_DIR:               return "vnd.android.cursor.dir/vnd."+AUTHORITY+".book";          case BOOK_ITEM:               return "vnd.android.cursor.item/vnd."+AUTHORITY+".book";          case CATEGORY_DIR:               return "vnd.android.cursor.dir/vnd."+AUTHORITY+".category";          case CATEGORY_ITEM:               return "vnd.android.cursor.item/vnd."+AUTHORITY+".category";          }          return null;     }     @Override     public Uri insert(Uri uri, ContentValues values) {          // 添加数据          SQLiteDatabase db = dbHelper.getReadableDatabase();          Uri uriReturn = null;          switch (uriMatcher.match(uri)) {          case BOOK_DIR:          case BOOK_ITEM:               long newBookId = db.insert("Book", null, values);               uriReturn = Uri.parse("content://" + AUTHORITY + "/book/"+ newBookId);               break;          case CATEGORY_DIR:          case CATEGORY_ITEM:               long newCategoryId = db.insert("Category", null, values);               uriReturn = Uri.parse("content://" + AUTHORITY + "/category/"+ newCategoryId);               break;          default:               break;          }          return uriReturn;     }     @Override     public int delete(Uri uri, String selection, String[] selectionArgs) {          // 删除数据          SQLiteDatabase db = dbHelper.getReadableDatabase();          int deleteRows = 0;          switch (uriMatcher.match(uri)) {          case BOOK_DIR:               deleteRows = db.delete("Book", selection, selectionArgs);               break;          case BOOK_ITEM:               String bookId = uri.getPathSegments().get(1);               deleteRows = db.delete("Book",  "id=?",new String[] { bookId });               break;          case CATEGORY_DIR:               deleteRows = db.delete("Category", selection, selectionArgs);               break;          case CATEGORY_ITEM:               String categoryId = uri.getPathSegments().get(1);               deleteRows = db.delete("Category",  "id=?",new String[] { categoryId });               break;          default:               break;          }          return deleteRows;     }     @Override     public int update(Uri uri, ContentValues values, String selection,               String[] selectionArgs) {          // 更新数据          SQLiteDatabase db = dbHelper.getReadableDatabase();          int updateRows = 0;          switch (uriMatcher.match(uri)) {          case BOOK_DIR:               updateRows = db.update("Book", values, selection, selectionArgs);               break;          case BOOK_ITEM:               String bookId = uri.getPathSegments().get(1);               updateRows = db.update("Book", values, "id=?",new String[] { bookId });               break;          case CATEGORY_DIR:               updateRows = db.update("Category", values, selection, selectionArgs);               break;          case CATEGORY_ITEM:               String categoryId = uri.getPathSegments().get(1);               updateRows = db.update("Category", values, "id=?",new String[] { categoryId });               break;          default:               break;          }          return updateRows;     }}

最后不要忘了在AndroidManifest.xml中进行注册：

<!-- 注册自定义的内容提供器 -->  <provider            android:name="com.android_3100_androidpersistence.DatabaseProvider"            android:authorities="com.android_3100_androidpersistence.provider"            android:exported="true"    ></provider>

注意：使用内容提供器时，如果报null异常，一般就是uri 和你定义的地址没有匹配上

22.SurfaceView 的基本框架 SurfaceView可以做许多交互性的东西，比如说最常见的互动游戏

package com.luckPan;import android.content.Context;import android.graphics.Canvas;import android.util.AttributeSet;import android.view.SurfaceHolder;import android.view.SurfaceHolder.Callback;import android.view.SurfaceView;public class SurfaceViewTemplate extends SurfaceView implements Callback, Runnable {    private SurfaceHolder mHolder;    private Canvas mCanvas;    /**     * 用于线程绘制     */    private Thread t;    /**     * 线程的控制开关     */    private boolean isRunning;    public SurfaceViewTemplate(Context context) {        this(context,null);    }    public SurfaceViewTemplate(Context context, AttributeSet attrs) {        super(context, attrs);        mHolder = getHolder();        mHolder.addCallback(this);        //设置可获得焦点        setFocusable(true);        setFocusableInTouchMode(true);        //设置常量        setKeepScreenOn(true);    }    public void surfaceCreated(SurfaceHolder holder) {        isRunning = true;        t = new Thread(this);        t.start();    }    public void surfaceChanged(SurfaceHolder holder, int format, int width,            int height) {    }    public void surfaceDestroyed(SurfaceHolder holder) {        isRunning = false;    }    public void run() {        while(isRunning){            draw();        }    }    private void draw() {        try {            mCanvas = mHolder.lockCanvas();            if (mCanvas != null) {                //draw something            }        } catch (Exception e) {        }finally{            if (mCanvas != null) {                mHolder.unlockCanvasAndPost(mCanvas);            }        }    }}