Image Zoom Over縮放

Question

我從啓用圖像的滾動和縮放的tut中獲得該代碼，但即使圖像很小，代碼也會拉伸圖像，以便填充整個屏幕。我希望它有一個可能包含圖像的對話框，並通過修改代碼來啓用縮放和滾動，而不佔用整個屏幕。

編輯：使用下面的代碼可以限制滾動或限制圖片的大小嗎？ 第一個顯示屏上有一個默認圖像尺寸（居中），這也是最小縮小。當圖像達到其最大可滾動大小（實際圖像大小）時，它將回到默認大小。如果可能的話，也控制在圖像可以滾動，所以我不會在縮放丟失的區域

public class ZoomHelloActivity extends Activity { 

    // Physical display width and height. 
    private static int displayWidth = 0; 
    private static int displayHeight = 0; 


    static String img=""; 

    /** Called when the activity is first created. */ 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 

     Display display = ((WindowManager) 
          getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay(); 
     displayWidth = display.getWidth(); 
     displayHeight = display.getHeight(); 

     //get intent 
     Bundle extras = getIntent().getExtras(); 

     if (extras != null) { 
      Toast.makeText(this.getBaseContext(),"Inside: "+img.toString(), 
        Toast.LENGTH_SHORT).show(); 
      img = extras.getString("img"); 
      // and get whatever type user account id is 
     } 
     else{ Toast.makeText(this.getBaseContext(),"ERROR ni", 
        Toast.LENGTH_SHORT).show();} 
     setContentView(new SampleView(this)); 


    } 

    private static class SampleView extends View { 
     private static Bitmap bmLargeImage; //bitmap large enough to be scrolled 
     private static Rect displayRect = null; //rect we display to 
     private Rect scrollRect = null; //rect we scroll over our bitmap with 
     private int scrollRectX = 0; //current left location of scroll rect 
     private int scrollRectY = 0; //current top location of scroll rect 
     private float scrollByX = 0; //x amount to scroll by 
     private float scrollByY = 0; //y amount to scroll by 
     private float startX = 0; //track x from one ACTION_MOVE to the next 
     private float startY = 0; //track y from one ACTION_MOVE to the next 

     public SampleView(Context context) { 
      super(context); 

      // Destination rect for our main canvas draw. It never changes. 
      displayRect = new Rect(0, 0, displayWidth, displayHeight); 
      // Scroll rect: this will be used to 'scroll around' over the 
      // bitmap in memory. Initialize as above. 
      scrollRect = new Rect(0, 0, displayWidth, displayHeight); 

      // Load a large bitmap into an offscreen area of memory. 
      int assignImg; 
      assignImg = Integer.parseInt(img); 
      bmLargeImage = BitmapFactory.decodeResource(getResources(), 
        assignImg); 
     } 

     @Override 
     public boolean onTouchEvent(MotionEvent event) { 
      switch (event.getAction()) { 
       case MotionEvent.ACTION_DOWN: 
        // Remember our initial down event location. 
        startX = event.getRawX(); 
        startY = event.getRawY(); 
        break; 

       case MotionEvent.ACTION_MOVE: 
        float x = event.getRawX(); 
        float y = event.getRawY(); 
        // Calculate move update. This will happen many times 
        // during the course of a single movement gesture. 
        scrollByX = x - startX; //move update x increment 
        scrollByY = y - startY; //move update y increment 
        startX = x; //reset initial values to latest 
        startY = y; 
        invalidate(); //force a redraw 
        break; 
      } 
      return true; //done with this event so consume it 
     } 

     @Override 
     protected void onDraw(Canvas canvas) { 
      int newScrollRectX = scrollRectX - (int)scrollByX; 
      int newScrollRectY = scrollRectY - (int)scrollByY; 

      // Don't scroll off the left or right edges of the bitmap. 
      if (newScrollRectX < 0) 
       newScrollRectX = 0; 
      else if (newScrollRectX > (bmLargeImage.getWidth() - displayWidth)) 
       newScrollRectX = (bmLargeImage.getWidth() - displayWidth); 

      // Don't scroll off the top or bottom edges of the bitmap. 
      if (newScrollRectY < 0) 
       newScrollRectY = 0; 
      else if (newScrollRectY > (bmLargeImage.getHeight() - displayHeight)) 
       newScrollRectY = (bmLargeImage.getHeight() - displayHeight); 

      // We have our updated scroll rect coordinates, set them and draw. 
      scrollRect.set(newScrollRectX, newScrollRectY, 
       newScrollRectX + displayWidth, newScrollRectY + displayHeight); 
      Paint paint = new Paint(); 
      canvas.drawBitmap(bmLargeImage, scrollRect, displayRect, paint); 

      // Reset current scroll coordinates to reflect the latest updates, 
      // so we can repeat this update process. 
      scrollRectX = newScrollRectX; 
      scrollRectY = newScrollRectY; 
     } 
    } 
} 

編輯： 通緝輸出：

Answer 1

也許嘗試以下方法：

在OnCreate()方法，而不是這樣的：

displayWidth = display.getWidth(); 
displayHeight = display.getHeight(); 

把如下：

private static Bitmap bmLargeImage; 
bmLargeImage = BitmapFactory.decodeResource(getResources(), assignImg); 
int bmWidth = bmLargeImage.getWidth(); 
int bmHeight = bmLargeImage.getHeight(); 

displayWidth = display.getWidth(); 
displayHeight = display.getHeight(); 

if (bmWidth < displayWidth){ 
    displayWidth = bmWidth; 
} 
if (bmHeight < displayHeight){ 
    displayHeight = bmHeight; 
} 

看看這是否可以繞開算法從嘖嘖。