android繁琐笔记六

android琐碎笔记六
1.得到屏幕的screen dimensions
Display display = getWindowManager().getDefaultDisplay();
int width = display.getWidth();int height = display.getHeight();

2. 播放 gif图片在android
@Override protected void onDraw(Canvas canvas) {          
canvas.drawColor(0xFFCCCCCC);                      
  Paint p = new Paint();           
  p.setAntiAlias(true);         
     
     canvas.drawBitmap(mBitmap4, 210, 170, null);           
     mDrawable.draw(canvas);           
     long now = android.os.SystemClock.uptimeMillis();          
      if (mMovieStart == 0) {   // first time                mMovieStart = now;            }           
      if (mMovie != null) {               
        int dur = mMovie.duration();               
           if (dur == 0) {                   
              dur = 1000;                }               
              int relTime = (int)((now - mMovieStart) % dur);               
              mMovie.setTime(relTime);             
                mMovie.draw(canvas, getWidth() - mMovie.width(),                         
                  getHeight() - mMovie.height());              
                   invalidate();           
                   }      
                    }
http://developer.android.com/guide/samples/ApiDemos/src/com/example/android/apis/graphics/BitmapDecode.html
@Override
                    protected void onDraw(Canvas canvas) {
                        if(movie != null) {
                                long now = android.os.SystemClock.uptimeMillis();
                                        int dur = Math.max(movie.duration(), 1);
                                        // is it really animated?       
                                        int pos = (int)(now % dur);       
                                        movie.setTime(pos);       
                                        movie.draw(canvas, x, y);
                                         invalidate();   
                                 }}

4. 打开sd卡中的sqllite
File dbfile = new File("/sdcard/mydb.sqlite" );
                                  SQLiteDatabase db = SQLiteDatabase.openOrCreateDatabase(dbfile, null);

5.得到手机的IMEI
((TelephonyManager) getSystemService=(Context.TELEPHONY_SERVICE)).getDeviceId();

6. 不让程序 生成一个appliation 去掉
<category android:name="android.intent.category.LAUNCHER" />
当然你的让你的程序 被引导启动

7.使用appliation 的id 可以获得不同appliation的数据：
android:sharedUserId="string" 在主xml中添加上面一句话，然后签名也要一样 两个app的id也要设置成一样 如都是string 那么这两个程序就可以相互访问彼此的数据，也可以在同一个process中了
8.判断相机设备存在不
private android.hardware.Camera mCameraDevice;
try { 
    mCameraDevice = android.hardware.Camera.open();}
catch (RuntimeException e) {  Log.e(TAG, "fail to connect Camera", e);

9使listView 透明
android:background="#00000000"
android:cacheColorHint="#00000000"
或者
android:background="@android:color/transparent"

?The background android screen image should be visible.
屏幕的背景图像可以看见
manifest file 添加attribute 到 activity.
android:theme="@android:style/Theme.Dialog"