Android開發小技巧總結

jopen 12年前發布 | 49K 次閱讀 Android Android開發移動開發
總結下一些相關技巧。
1 全屏
super.onCreate(savedInstanceState);        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.main);</pre> 
  
 
  2 取得屏幕像素 
   
  DisplayMetrics dm=new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(dm);</pre> 
  
 
  3 簡單拍照 
   
  button.setOnClickListener(new OnClickListener(){

       @Override

       public void onClick(View arg0) {         

          Intent intent = new Intent("android.media.action.IMAGE_CAPTURE");      startActivityForResult(intent,SELECT_PICTURE_FROM_CAMERA); 

       }

    });


//然后重載startActivityForResult添加自己的實現
@Override

protected void onActivityResult(int requestCode, int resultCode, Intent data) {

if( resultCode==RESULT_OK)

{

    if(requestCode==SELECT_PICTURE_FROM_CAMERA)

    {

        File image=new File(Environment.getExternalStorageDirectory(), "camera.jpg");

        selectedImagePath=image.getAbsolutePath();

        Drawable d=Drawable.createFromPath(selectedImagePath);

        ImageView.setImageDrawable(d);

    }

}


} </pre> 
  
 
  4 從android本地多媒體圖片文件夾中選擇圖片 
   
  Intent i=new Intent(Intent.ACTION_GET_CONTENT);

          i.setType("image/*");

          Intent wrapi=Intent.createChooser(i, "choose");

          startActivityForResult(wrapi, SELECT_PICTURE_FROM_FILE);


//然后重載startActivityForResult添加自己的實現
@Override

protected void onActivityResult(int requestCode, int resultCode, Intent data) {

if( resultCode==RESULT_OK)

{

    if(requestCode==SELECT_PICTURE_FROM_FILE )

    {

    Uri selectedImageUri = data.getData();

    selectedImagePath=getPath(selectedImageUri);

    imageView.setImageURI(selectedImageUri);

    }

}


}   //獲取當前選擇的圖片，并顯示在imageView上

private String getPath(Uri uri)

{

String[] projection={MediaStore.Images.Media.DATA};

Cursor cursor=managedQuery(uri,projection,null,null,null);

int column_index=cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);

cursor.moveToFirst();

return cursor.getString(column_index);


}
//Query實現從圖片數據庫中查詢到所要記錄</pre> 
  
 
  5 Activity之間帶內容的跳轉 
   
  Intent intent = new Intent();

              Bundle imageMsg = new Bundle();

              imageMsg.putString("filePath", selectedImagePath); /               intent.putExtras(imageMsg);

              intent.setClass(ActivityA.this,ActivityB.class);

              startActivity(intent);

              ActivityA.this.finish();</pre> 

 
  6 位圖縮放 
  public Bitmap zoomImage(Bitmap bgimage, int newWidth, int newHeight) {     
         int width = bgimage.getWidth(); 
         int height = bgimage.getHeight(); 
    
         Matrix matrix = new Matrix(); 
    
         float scaleWidth = ((float) newWidth) / width; 
         float scaleHeight = ((float) newHeight) / height; 
    
         matrix.postScale(scaleWidth, scaleHeight); 
         Bitmap bitmap = Bitmap.createBitmap(bgimage, 0, 0, width, height, 
         matrix, true); 
         return bitmap; 
    
         } 
  7 Gallery的使用 
  Gallery gallery=(Gallery)findViewById(R.id.gallery); 
          myImageAdapter imageadapter=new myImageAdapter(this); //傳入context 
          gallery.setAdapter(imageadapter); 
          gallery.setOnItemClickListener(new Gallery.OnItemClickListener(){ 
             @Override 
             public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,long arg3) { 
                Bitmap selectedBitmap=BitmapFactory.decodeResource(getResources(),imageadapter.myImageIds[arg2]); 
             } 
          }); 
          gallery.setSelection(1); 
  //adapter的類定義 
  public class myImageAdapter extends BaseAdapter{ 
    
      int mGalleryItemBackground; 
      private Context context; 
      public Integer[] myImageIds={ 
             //圖片的資源id號 
      }; 
      public myImageAdapter(Context context) 
      { 
         this.context=context; 
         TypedArray typed_array=context.obtainStyledAttributes(R.styleable.Gallery); 
          
      mGalleryItemBackground=typed_array.getResourceId(R.styleable.Gallery_android_galleryItemBackground   , 0); 
         //mGalleryItemBackground++; 
         typed_array.recycle(); 
      } 
      @Override 
      public int getCount() { 
         // TODO Auto-generated method stub 
         return myImageIds.length; 
      } 
    
      @Override 
      public Object getItem(int arg0) { 
         // TODO Auto-generated method stub 
         return arg0; 
      } 
    
      @Override 
      public long getItemId(int arg0) { 
         // TODO Auto-generated method stub 
         return arg0; 
      } 
    
      @Override 
      public View getView(int arg0, View arg1, ViewGroup arg2) { 
         // TODO Auto-generated method stub 
         ImageView imageView=new ImageView(context); 
         imageView.setImageResource(myImageIds[arg0]); 
          
         imageView.setScaleType(ImageView.ScaleType.FIT_XY); 
         imageView.setLayoutParams(new Gallery.LayoutParams(128,128)); 
         imageView.setBackgroundResource(mGalleryItemBackground); 
         return imageView; 
      } 
    
  } 
  8 activity中使用線程 
  private Handler mHandler=new Handler(); 
  private Runnable mRunnable=new Runnable() 
      { 
         @Override 
         public void run() { 
             // TODO Auto-generated method stub 
         } 
  }; 
  mHandler.post(mRunnable);              //啟動線程 
  9 保存到android多媒體圖片文件夾 
  android.provider.MediaStore.Images.Media.insertImage(getContentResolver(),resultBitmap, "picName", "descrition"); 
  10 其他技巧摘錄自網絡，見鏈接 
  1 android開發環境安裝 
  2 Android模擬器中使用sdcard 
  http://blog.csdn.net/unix_fans/archive/2009/08/20/4465038.aspx 
  http://blog.csdn.net/jinlking/archive/2009/03/03/3953319.aspx 
  3 Android Intent 大全 
  在Android中調用圖片視頻、音頻、錄音、拍照： 
  http://blog.csdn.net/bdwgbdwg/archive/2010/11/23/6029208.aspx 
  4 Android.Content.Provider.rar 
  5 Android中三種使用線程的方法.rar 
  11 Activity之間動態跳轉(摘自網絡) 
  //頁面跳轉
      int  version = Integer.valueOf(android.os.Build.VERSION.SDK);      
      if (version  >=  5 ) {      
         overridePendingTransition(R.anim.zoomin, R.anim.zoomout);  //此為自定義的動畫效果，下面兩個為系統的動畫效果    
         //overridePendingTransition(android.R.anim.fade_in,android.R.anim.fade_out);      
         //overridePendingTransition(android.R.anim.slide_in_left,android.R.anim.slide_out_right);    
      }     
      //頁面跳轉 
       //zoomin.xml 
  <?xml version="1.0" encoding="utf-8"?>
 <set  xmlns:android="http://schemas.android.com/apk/res/android"    
         android:interpolator="@android:anim/decelerate_interpolator" >   
     <scale android:fromXScale="2.0"  android:toXScale= "1.0"    
            android:fromYScale="2.0"  android:toYScale= "1.0"    
            android:pivotX="50%p"  android:pivotY= "50%p"    
            android:duration="@android:integer/config_mediumAnimTime"  />
 </set>
 //zoomout.xml 
  <?xml version="1.0" encoding="utf-8"?>
 <set xmlns:android="http://schemas.android.com/apk/res/android"    
         android:interpolator="@android:anim/decelerate_interpolator"    
         android:zAdjustment="top" >   
     <scale android:fromXScale="1.0"  android:toXScale= ".5"    
            android:fromYScale="1.0"  android:toYScale= ".5"    
            android:pivotX="50%p"  android:pivotY= "50%p"    
            android:duration="@android:integer/config_mediumAnimTime"  />   
     <alpha android:fromAlpha="1.0"  android:toAlpha= "0"    
            android:duration="@android:integer/config_mediumAnimTime" /> 
 </set> 
  12 模擬按鈕press和release的效果 
  http://blog.csdn.net/sytzz/archive/2010/06/16/5673662.aspx 
  13 實現畫出一個透明的點 
    Paint paint=new Paint(); 
    paint.setColor(Color.BLUE); 
   paint.setAlpha(0);   
    canvas.drawPoint(x, y, paint); 
    這樣就好了嗎？ no，你需要把你的canvas建立在一個允許透明的bitmap上，如下 
    blankBitmap=Bitmap.createBitmap(picWidth, picHeight, Config.ARGB_8888);//不是Config.sRGB_565
   Canvas c = new Canvas(blankBitmap);  
  
 作者： 
  Aga.J 
  
 出處： 
  http://www.cnblogs.com/aga-j
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Android Android開發移動開發
Android開發小技巧總結

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