Effects of dragging Images

The first Google summer College Students' blog sharing competition-2010 andriod

I used my milestone to download and install Tencent's "QQ Browser". I felt that the frequently-used Web site column can be used to drag the image effects like the iPhone, so I wanted to follow suit.

This effect can be easily achieved in Android, but some skills are required, including Android. content. Context, Android. widget. baseadapter, and Android. widget. imageview. In activity, content is equivalent to a canvas. in layout, a gallery object is laid out and the image required by Gallery is stored in the baseadapter container.

1. Write your own internal class imageadapter inheritance and baseadapter, override getcount (), getitem (INT arg0), etitemid (INT arg0), getview (INT position, view convertview, viewgroup parent) method.

2. Import your own image file as the image to be displayed. In the Res/drawable folder, select import and import the file, however, before importing, you must note that the file name must contain lowercase letters, numbers, underscores, and decimal places. Otherwise"Res \ drawable-hdpi \ document.png: invalid file name: must contain only [a-z0-9 _.]"Error message. After successful addition, related records will be automatically added to R. Java:

  Public     Static     Final     Class  Drawable {

  Public     Static     Final     Int Document  =  0x7f020000  ;

  Public     Static     Final     Int  Email  =  0x7f020001  ;

  Public    Static     Final     Int  Icon  =  0x7f020002  ;

  Public     Static     Final     Int  Im  = 0x7f020003  ;

  Public     Static     Final     Int  Music  =  0x7f020004  ;

  Public     Static    Final     Int  Vedio  =  0x7f020005  ;

}

 

3. Add an array to the internal class imageadpter and put the added image resources in the array for future calls

 

  Private Int[] Myimageids=

{

R. drawable. email,

R.drawable.doc ument,

R. drawable. Im,

R. drawable. Music,

R. drawable. vedio

};
 

 

 

4. Create an imageview object in the getview method:

 

  // New Object  
  
Imageview iview  =     New  Imageview (  This  . Mycontext );

Iview. setimageresource (myimageids [position]);

Iview. setscaletype (imageview. scaletype. fit_xy );

  //  Set the width and height of the imageview object  
  
Iview. setlayoutparams (  New Gallery. layoutparams (  128  ,  128  ));
 

 

 

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Download source code

Complete internal class imageadapterCode:

  1   Public     Class Imageadapter  Extends  Baseadapter {
  2   
  3     Private  Context mycontext  =     Null  ;
  4   
  5    /*  Save custom images to several groups  */  
  6     Private     Int  [] Myimageids  =   
  7   {
  8   R.drawable.doc ument,
  9  R. drawable. Music,
  10   R. drawable. email,
  11   R. drawable. Im,
  12   R. drawable. vedio
  13   };
  14   
  15     /**  
  16  * Constructor
  17   *  @ Param  C
  18     */  
  19     Public  Imageadapter (context c ){
  20     This . Mycontext  =  C;
  21   }
  22     /**  
  23   * Returns the total number of images of all definitions.
  24     */  
  25   @ Override
 26     Public     Int  Getcount (){
  27     //  Todo auto-generated method stub  
  28        Return     This . Myimageids. length;
  29   }
  30   
  31   @ Override
  32     Public  Object getitem (  Int  Arg0 ){
  33     // Todo auto-generated method stub  
  34        Return  Arg0;
  35   }
  36   
  37   @ Override
  38     Public    Long  Getitemid (  Int  Arg0 ){
  39     //  Todo auto-generated method stub  
  40        Return  Arg0;
  41  }
  42   
  43     /**  
  44   * Obtain the view of the image to be displayed.
  45   * Input an array id value for reading and Imaging
  46     */  
  47  @ Override
  48     Public  View getview (  Int  Position, view convertview, viewgroup parent ){
  49     //  Todo auto-generated method stub  
  50     Imageview iview =     New  Imageview (  This  . Mycontext );
  51   Iview. setimageresource (myimageids [position]);
  52   Iview. setscaletype (imageview. scaletype. fit_xy );
  53   Iview. setlayoutparams (  New  Gallery. layoutparams (  128 ,  128  ));
  54     Return  Iview;
  55   }
  56   
  57   }
  58