如何根據黑莓的高度和寬度調整圖像大小

Question

如何調整來自HTTP服務器的圖像的大小和黑莓屏幕的寬度？請任何解決方案。

Answer 1

從圖像的字節創建一個EncodedImage。

使用Display.getHeight()和Display.getWidth()來獲得顯示器的尺寸。

然後使用EncodedImage.scaleImage32()進行調整大小。請確認this post。

Answer 2

嘗試使用參數Disply.getWidth（）& Display.getHieght（）。

package CustomizedField; 

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

public class GPATools 
{ 
    /** 
    * Resizes a bitmap with an alpha channel (transparency) 
    * without the artifacts introduced 
    * by <code>scaleInto()</code>. 
    * 
    * @param bmpSrc  Source Bitmap 
    * @param nWidth  New Width 
    * @param nHeight  New Height 
    * @param nFilterType Filter quality to use. Can be   
    *       <code>Bitmap.FILTER_LANCZOS</code>, 
    *       <code>Bitmap.FILTER_BILINEAR</code> or 
    *       <code>Bitmap.FILTER_BOX</code>. 
    * @param nAspectRatio Specifies how the picture is resized. Can be 
    *       <code>Bitmap.SCALE_TO_FIT</code>, 
    *       <code>Bitmap.SCALE_TO_FILL</code> or 
    *       <code>Bitmap.SCALE_STRETCH</code>. 
    * @return    The resized Bitmap in a new object. 
    */ 
    public static Bitmap ResizeTransparentBitmap(Bitmap bmpSrc, 
    int nWidth, int nHeight, int nFilterType, int nAspectRatio) 
    { 
     if(bmpSrc== null) 
      return null; 

     //Get the original dimensions of the bitmap 
     int nOriginWidth = bmpSrc.getWidth(); 
     int nOriginHeight = bmpSrc.getHeight(); 
     if(nWidth == nOriginWidth && nHeight == nOriginHeight) 
      return bmpSrc; 

     //Prepare a drawing bitmap and graphic object 
     Bitmap bmpOrigin = new Bitmap(nOriginWidth, nOriginHeight); 
     Graphics graph = Graphics.create(bmpOrigin); 

     //Create a line of transparent pixels for later use 
     int[] aEmptyLine = new int[nWidth]; 
     for(int x = 0; x < nWidth; x++) 
      aEmptyLine[x] = 0x00000000; 
     //Create two scaled bitmaps 
     Bitmap[] bmpScaled = new Bitmap[2]; 
     for(int i = 0; i < 2; i++) 
     { 
      //Draw the bitmap on a white background first, 
      //then on a black background 
      graph.setColor((i == 0) ? Color.WHITE : Color.BLACK); 
      graph.fillRect(0, 0, nOriginWidth, nOriginHeight); 
      graph.drawBitmap(0, 0, nOriginWidth, nOriginHeight, bmpSrc, 0, 0); 

      //Create a new bitmap with the desired size 
      bmpScaled[i] = new Bitmap(nWidth, nHeight); 
      if(nAspectRatio == Bitmap.SCALE_TO_FIT) 
      { 
       //Set the alpha channel of all pixels to 0 
       //to ensure transparency is 
       //applied around the picture, if needed by the transformation 
       for(int y = 0; y < nHeight; y++) 
        bmpScaled[i].setARGB(aEmptyLine, 0, nWidth, 
         0, y, nWidth, 1); 
      } 

      //Scale the bitmap 
      bmpOrigin.scaleInto(bmpScaled[i], nFilterType, nAspectRatio); 
     } 

     //Prepare objects for final iteration 
     Bitmap bmpFinal = bmpScaled[0]; 
     int[][] aPixelLine = new int[2][nWidth]; 

     //Iterate every line of the two scaled bitmaps 
     for(int y = 0; y < nHeight; y++) 
     { 
      bmpScaled[0].getARGB(aPixelLine[0], 0, nWidth, 0, y, nWidth, 1); 
      bmpScaled[1].getARGB(aPixelLine[1], 0, nWidth, 0, y, nWidth, 1); 

      //Check every pixel one by one 
      for(int x = 0; x < nWidth; x++) 
      { 
       //If the pixel was untouched (alpha channel still at 0), 
       //keep it transparent 
       if(((aPixelLine[0][x] >> 24) & 0xff) == 0) 
        aPixelLine[0][x] = 0x00000000; 
       else 
       { 
        //Compute the alpha value based on the difference 
        //of intensity in the red channel 
        int nAlpha = ((aPixelLine[1][x] >> 16) & 0xff) - 
            ((aPixelLine[0][x] >> 16) & 0xff) + 255; 
        if(nAlpha == 0) 
         aPixelLine[0][x] = 0x00000000; //Completely transparent 
        else if(nAlpha >= 255) 
         aPixelLine[0][x] |= 0xff000000; //Completely opaque 
        else 
        { 
         //Compute the value of the each channel one by one 
         int nRed = ((aPixelLine[0][x] >> 16) & 0xff); 
         int nGreen = ((aPixelLine[0][x] >> 8) & 0xff); 
         int nBlue = (aPixelLine[0][x] & 0xff); 

         nRed = (int)(255 + 
          (255.0 * ((double)(nRed-255)/(double)nAlpha))); 
         nGreen = (int)(255 + 
          (255.0 * ((double)(nGreen-255)/(double)nAlpha))); 
         nBlue = (int)(255 + 
          (255.0 * ((double)(nBlue-255)/(double)nAlpha))); 

         if(nRed < 0) nRed = 0; 
         if(nGreen < 0) nGreen = 0; 
         if(nBlue < 0) nBlue = 0; 
         aPixelLine[0][x] = nBlue | (nGreen<<8) | 
          (nRed<<16) | (nAlpha<<24); 
        } 
       } 
      } 

      //Change the pixels of this line to their final value 
      bmpFinal.setARGB(aPixelLine[0], 0, nWidth, 0, y, nWidth, 1); 
     } 
     return bmpFinal; 
    } 
} 

Answer 3

這裏是一個調整圖片大小，任何大小的方法：

public EncodedImage resizeImage(EncodedImage image, int newWidth, int newHeight) 
      { 
         int scaleFactorX = Fixed32.div(Fixed32.toFP(image.getWidth()), Fixed32.toFP(newWidth)); 
         int scaleFactorY = Fixed32.div(Fixed32.toFP(image.getHeight()), Fixed32.toFP(newHeight)); 
         return image.scaleImage32(scaleFactorX, scaleFactorY); 
      } 

你要只是傳遞的寬度和高度 - 要在其中調整圖片的大小作爲參數。

您可以分別使用Display.getWidth() & Display.getHeight()獲得顯示屏的寬度和高度。