Simple implementation of surfaceview for Android Learning

The following is a smallProgramCodeSurfaceview is used to draw a circle on the screen. You can change the circle position by pressing the arrow key and touching the screen.

Mainactivity

 1   Package Com. view;
 2  
 3   Import Android. App. activity;
 4   Import Android. OS. Bundle;
 5  Import Android. View. window;
 6   Import Android. View. windowmanager;
 7  
 8   Public   Class Mainactivity Extends Activity {
 9       /**  Called when the activity is first created.  */ 
 10 @ Override
 11       Public   Void Oncreate (bundle savedinstancestate ){
 12           Super . Oncreate (savedinstancestate );
 13  
 14           //  Hide Status Bar  
  15             This . Getwindow (). setflags (windowmanager. layoutparams. flag_fullscreen,
 16 Windowmanager. layoutparams. flag_fullscreen );
 17  
 18           //  Remove the Activity title  
  19    Requestwindowfeature (window. feature_no_title );
 20  
 21           //  Set Layout  
  22            This . Setcontentview ( New Mysurfaceview ( This ));
 23 }
 24 }

Mainactivity mainly sets the screen full screen.

Mysurfaceview

 1   Package Com. view;
 2  
 3   Import Android. content. context;
 4   Import Android. Graphics. Canvas;
 5   Import Android. Graphics. color;
 6   Import Android. Graphics. paint;
 7   Import Android. View. keyevent;
8   Import Android. View. motionevent;
 9   Import Android. View. surfaceholder;
 10   Import Android. View. surfaceholder. Callback;
 11   Import Android. View. surfaceview;
 12  
 13   Public   Class MysurfaceviewExtends Surfaceview Implements Runnable, callback {
 14  
 15       Private Surfaceholder mholder; //  Used to control surfaceview  
  16    
 17       Private Thread t; //  Declare a thread 
  18    
 19       Private   Boolean Flag; //  The ID of the thread running, used to control the thread  
  20    
 21       Private Canvas mcanvas; //  Declare a canvas  
 22    
 23       Private Paint P; //  Declare a paint brush  
  24    
 25       Private   Int X = 50, y = 50, r = 10; //  Coordinates and radius of the circle  
  26   
 27       Public Mysurfaceview (context ){
 28           Super (Context );
 29  
 30 Mholder = getholder (); //  Get surfaceholder object  
  31    Mholder. addcallback ( This );//  Add status listening for surfaceview  
  32    P = New Paint (); //  Create a paint brush object  
  33    P. setcolor (color. White ); //  Set the paint brush color to white  
  34    Setfocusable ( True ); //  Set focus  
  35    }
 36  
 37       /**  
  38   * Customize a method and draw a circle on the canvas
  39     */ 
40       Public   Void Draw (){
 41 Mcanvas = mholder. lockcanvas (); //  Get the canvas object and start painting the canvas.  
  42    Mcanvas. drawrgb (0, 0, 0 ); //  Fill the canvas in black  
  43    Mcanvas. drawcircle (X, Y, R, P );//  Draw a circle  
  44    Mholder. unlockcanvasandpost (mcanvas ); //  Finish painting and display the canvas on the screen  
  45    }
 46  
 47       /**  
  48  * This function is called when surfaceview is created.
  49     */ 
 50 @ Override
 51       Public   Void Surfacecreated (surfaceholder holder ){
 52 T = New Thread ( This ); //  Create a thread object 
  53    Flag = True ; //  Set the thread running identifier to true.  
  54    T. Start (); //  Start thread  
  55    }
 56  
57       /**  
  58   * This function is called when the surfaceview view changes.
  59     */ 
 60 @ Override
 61       Public   Void Surfacechanged (surfaceholder holder, Int Format, Int Width,
62               Int Height ){
 63 }
 64  
 65       /**  
  66   * This function is called when surfaceview is destroyed.
  67     */ 
 68 @ Override
 69      Public   Void Surfacedestroyed (surfaceholder holder ){
 70 Flag = False ; //  Set the thread running identifier to false.  
  71    }
 72  
 73       /**  
  74  * Called when the screen is touched
  75     */ 
 76 @ Override
 77       Public   Boolean Ontouchevent (motionevent event ){
 78 X = ( Int ) Event. getx (); //  Obtain the x-axis coordinates of the screen when it is touched.  
  79   Y = ( Int ) Event. Gety (); //  Obtain the Y axis coordinates of the screen when it is touched.  
  80             Return   True ;
 81 }
 82      
 83       /**  
  84  * Called when a user presses a key
  85     */ 
 86 @ Override
 87       Public   Boolean Onkeydown ( Int Keycode, keyevent event ){
 88           If (Keycode = keyevent. keycode_dpad_up ){ //  When a user clicks the primary key  
 89    Y --; //  Set Y axis minus 1  
  90    }
 91           Return   Super . Onkeydown (keycode, event );
 92 }
 93  
 94 @ Override
95       Public   Void Run (){
 96           While (FLAG ){
 97 Draw (); //  Call the custom painting Method  
  98                 Try {
 99 Thread. Sleep (50 ); // Let the thread rest for 50 milliseconds  
  100    } Catch (Interruptedexception e ){
 101 E. printstacktrace ();
 102 }
 103 }
 104 }
 105  
 106 }

Mysurfaceview inherits surfaceview, implements runnable and callback interfaces, and overwrites the runnable run method and callback surfacecreated (surfaceholder holder ),Surfacechanged (surfaceholder holder, int format, int width,Int height), surfacedestroyed (surfaceholder holder) method, also implements the ontouchevent (motionevent event), onkeydown (INT keycode, keyevent event) method, detailed in the code has been commented out.