BlackBerry中的圖像按鈕

Question

如何在BlackBerry中實現圖像按鈕？

Answer 1

在這裏你走，完整代碼：

import net.rim.device.api.system.Bitmap; 
import net.rim.device.api.ui.Graphics; 
import net.rim.device.api.ui.component.ButtonField; 

/** 
* Button field with a bitmap as its label. 
*/ 
public class BitmapButtonField extends ButtonField { 
     private Bitmap bitmap; 
     private Bitmap bitmapHighlight; 
     private boolean highlighted = false; 

     /** 
     * Instantiates a new bitmap button field. 
     * 
     * @param bitmap the bitmap to use as a label 
     */ 
     public BitmapButtonField(Bitmap bitmap, Bitmap bitmapHighlight) { 
      this(bitmap, bitmapHighlight, ButtonField.CONSUME_CLICK|ButtonField.FIELD_HCENTER|ButtonField.FIELD_VCENTER); 
     } 

     public BitmapButtonField(Bitmap bitmap, Bitmap bitmapHighlight, long style) { 
      super(style); 
      this.bitmap = bitmap; 
      this.bitmapHighlight = bitmapHighlight; 
     } 

     /* (non-Javadoc) 
     * @see net.rim.device.api.ui.component.ButtonField#layout(int, int) 
     */ 
     protected void layout(int width, int height) { 
       setExtent(getPreferredWidth(), getPreferredHeight()); 
     } 

     /* (non-Javadoc) 
     * @see net.rim.device.api.ui.component.ButtonField#getPreferredWidth() 
     */ 
     public int getPreferredWidth() { 
       return bitmap.getWidth(); 
     } 

     /* (non-Javadoc) 
     * @see net.rim.device.api.ui.component.ButtonField#getPreferredHeight() 
     */ 
     public int getPreferredHeight() { 
       return bitmap.getHeight(); 
     } 

     /* (non-Javadoc) 
     * @see net.rim.device.api.ui.component.ButtonField#paint(net.rim.device.api.ui.Graphics) 
     */ 
     protected void paint(Graphics graphics) { 
       super.paint(graphics); 
       int width = bitmap.getWidth(); 
       int height = bitmap.getHeight(); 
       Bitmap b = bitmap; 
       if (highlighted) 
        b = bitmapHighlight; 
       graphics.drawBitmap(0, 0, width, height, b, 0, 0); 
     } 

     public void setHighlight(boolean highlight) 
     { 
      this.highlighted = highlight;   
     } 
} 

Answer 2

使用RIM的高級UI包。

http://supportforums.blackberry.com/t5/Java-Development/Implement-advanced-buttons-fields-and-managers/ta-p/488276

這包含BitmapButton場和大量的有用的UI工具。

（毫無疑問Reflogs例子是好的，但我認爲，新的BB開發商登陸此頁面的高級UI包是更有益的）

Answer 3

perfect ImageButton for Blackberry , According to user point of view a Imagebutton should have four states 
1. Normal 
2. Focus 
3. Selected Focus 
4. Selected unfocus 

the Following code maintain all four states (Field-Change-Listener and Navigation) 
if you want to maintain all four states than use 1st Constructor, If you just want to handle Focus/Un-Focu state of the button than use 2nd one 

######################################## 

import net.rim.device.api.system.Bitmap; 
import net.rim.device.api.ui.Field; 
import net.rim.device.api.ui.Graphics; 

public class ImageButton extends Field 
{ 

    Bitmap mNormalIcon; 
    Bitmap mFocusedIcon; 
    Bitmap mActiveNormalIcon; 
    Bitmap mActiveFocusedIcon; 
    Bitmap mActiveBitmap; 
    String mActiveText; 
    int mHeight; 
    int mWidth; 

    boolean isStateActive = false; 
    boolean isTextActive = false; 

    public boolean isStateActive() 
    { 
     return isStateActive; 
    } 



    public ImageButton(Bitmap normalIcon, Bitmap focusedIcon) 
    { 
     super(Field.FOCUSABLE | FIELD_VCENTER); 
     mNormalIcon = normalIcon; 
     mFocusedIcon = focusedIcon; 
     mActiveBitmap = normalIcon; 
     mActiveFocusedIcon = focusedIcon; 
     mActiveNormalIcon = normalIcon; 
     // isTextActive = false; 
    } 

    public ImageButton(Bitmap normalIcon, Bitmap focusedIcon, Bitmap activeNormalIcon, Bitmap activeFocusedIcon) 
    { 
     super(Field.FOCUSABLE | FIELD_VCENTER); 
     mNormalIcon = normalIcon; 
     mFocusedIcon = focusedIcon; 
     mActiveFocusedIcon = activeFocusedIcon; 
     mActiveNormalIcon = activeNormalIcon; 
     mActiveBitmap = normalIcon; 
     // isTextActive = true; 
    } 



    protected void onFocus(int direction) 
    { 
     if (!isStateActive) 
     { 

      mActiveBitmap = mFocusedIcon; 

     } 
     else 
     { 

      mActiveBitmap = mActiveFocusedIcon; 
     } 

    } 

    protected void onUnfocus() 
    { 

     super.onUnfocus(); 
     if (!isStateActive) 
     { 

      mActiveBitmap = mNormalIcon; 

     } 
     else 
     { 

      mActiveBitmap = mActiveNormalIcon; 

     } 

    } 

    protected boolean navigationClick(int status, int time) 
    { 

     mActiveBitmap = mActiveNormalIcon; 

     toggleState(); 
     invalidate(); 
     fieldChangeNotify(1); 
     return true; 
    } 

    public void toggleState() 
    { 
     isStateActive = !isStateActive; 
    } 

    public int getPreferredWidth() 
    { 
     return mActiveBitmap.getWidth() + 20; 

    } 

    public int getPreferredHeight() 
    { 
     return mActiveBitmap.getHeight() + 10; 

    } 

    protected void layout(int width, int height) 
    { 

     mWidth = getPreferredWidth(); 
     mHeight = getPreferredHeight(); 
     setExtent(mWidth, mHeight); 

    } 

    protected void paint(Graphics graphics) 
    { 

     graphics.drawBitmap(0, 5, mWidth, mHeight, mActiveBitmap, 0, 0); 
     // graphics.setColor(0xff0000); 
     // graphics.drawText(mActiveText, (mActiveBitmap.getWidth() - 
     // this.getFont().getAdvance("ON"))/2, mActiveBitmap.getHeight()); 

    } 

    protected void drawFocus(Graphics graphics, boolean on) 
    { 

    } 

    public void activate() 
    { 
     mActiveBitmap = mActiveNormalIcon; 

     isStateActive = true; 

     invalidate(); 
    } 

    public void deactivate() 
    { 

     mActiveBitmap = mNormalIcon; 

     isStateActive = false; 

     invalidate(); 
    } 

} 

Answer 4

最簡單的方式做到這一點：

第1步：用特定座標繪製圖像（imageX，imageY）。 第2步：添加一個方法在你的代碼：

void pointerControl(int x, int y) { 
     if (x>imageX && x<imageX+imageName.getWidth() && y>imageY && y < imageY+imageName.getHeight) { 
      //to do code here 
     } 

    } 

    where imageName:name of image 
      imageX=x coordinate of image(Top-Left) 
      imageY=y coordinate of image(Top-Left)