如何根據手機屏幕大小增加位圖圖像大小？

Question

我正在使用庫從url中獲取圖像，並將其保存爲位圖圖像。但是當我檢索到這個圖像時，它非常小。根據手機屏幕如何增加位圖圖像的高度和寬度？ 這裏是創建位圖的類。

public class ImageLoader { 

    int width,height; 
    MemoryCache memoryCache=new MemoryCache(); 
    FileCache fileCache; 
    private Map<ImageView, String> imageViews=Collections.synchronizedMap(new WeakHashMap<ImageView, String>()); 
    ExecutorService executorService; 
    Handler handler=new Handler();//handler to display images in UI thread 

    public ImageLoader(Context context){ 
     fileCache=new FileCache(context); 
     executorService=Executors.newFixedThreadPool(5); 
    } 

    final int stub_id=R.drawable.tnlrocks; 

    public void DisplayImage(String url, ImageView imageView) 
    { 
     imageViews.put(imageView, url); 
     Bitmap bitmap=memoryCache.get(url); 
     if(bitmap!=null) 
      imageView.setImageBitmap(bitmap); 
     else 
     { 
      queuePhoto(url, imageView); 
      imageView.setImageResource(stub_id); 
     } 
    } 

    private void queuePhoto(String url, ImageView imageView) 
    { 
     PhotoToLoad p=new PhotoToLoad(url, imageView); 
     executorService.submit(new PhotosLoader(p)); 
    } 

    private Bitmap getBitmap(String url) 
    { 
     File f=fileCache.getFile(url); 

     //from SD cache 
     Bitmap b = decodeFile(f); 
     if(b!=null) 
      return b; 

     //from web 
     try { 
      Bitmap bitmap=null; 
      URL imageUrl = new URL(url); 
      HttpURLConnection conn = (HttpURLConnection)imageUrl.openConnection(); 
      conn.setConnectTimeout(300000000); 
      conn.setReadTimeout(300000000); 
      conn.setInstanceFollowRedirects(true); 
      InputStream is=conn.getInputStream(); 
      OutputStream os = new FileOutputStream(f); 
      Utils.CopyStream(is, os); 
      os.close(); 
      conn.disconnect(); 
      bitmap = decodeFile(f); 
      return bitmap; 
     } catch (Throwable ex){ 
      ex.printStackTrace(); 
      if(ex instanceof OutOfMemoryError) 
       memoryCache.clear(); 
      return null; 
     } 
    } 

    public void getDimension(int width,int height){ 
     this.width=width; 
     this.height=height; 

    } 
    //decodes image and scales it to reduce memory consumption 
    private Bitmap decodeFile(File f){ 
     try { 
      //decode image size 
      final int IMAGE_MAX_SIZE = 120000000; // 1.2MP 



      BitmapFactory.Options o = new BitmapFactory.Options(); 
      o.inJustDecodeBounds = true; 
      FileInputStream stream1=new FileInputStream(f); 
      BitmapFactory.decodeStream(stream1,null,o); 
      stream1.close(); 

      //Find the correct scale value. It should be the power of 2. 
      final int REQUIRED_SIZE=70; 
      int width_tmp=o.outWidth, height_tmp=o.outHeight; 
      int scale=1; 
      while(true){ 
       if(width_tmp/2<REQUIRED_SIZE || height_tmp/2<REQUIRED_SIZE) 
        break; 
       width_tmp=width; 
       height_tmp=height; 

       scale*=2; 
      } 
      // int scale = 1; 
      while ((o.outWidth * o.outHeight) * (1/Math.pow(scale, 2)) > 
        IMAGE_MAX_SIZE) { 
       scale++; 

      } 
      // Log.d(TAG, "scale = " + scale + ", orig-width: " + o.outWidth + ",orig-height: " + o.outHeight); 

      Bitmap b = null; 

      if (scale > 1) { 
       scale--; 
       //scale*=2; 
       // scale to max possible inSampleSize that still yields an image 
       // larger than target 
       o = new BitmapFactory.Options(); 
       o.inSampleSize = scale; 
       b = BitmapFactory.decodeStream(stream1, null, o); 

       // resize to desired dimensions 
       int height = b.getHeight(); 
       int width = b.getWidth(); 


       // double y = Math.sqrt(IMAGE_MAX_SIZE 
       //  /(((double) width)/height)); 
       double y=height; 
       double x=width; 
       // double x = (y/height) * width; 

       Bitmap scaledBitmap = Bitmap.createScaledBitmap(b, (int) x, 
        (int) y, true); 
       b.recycle(); 
       b = scaledBitmap; 

       System.gc(); 
      } else { 
       b = BitmapFactory.decodeStream(stream1); 
      } 

      //decode with inSampleSize 
      BitmapFactory.Options o2 = new BitmapFactory.Options(); 
      o2.inSampleSize=scale; 
      FileInputStream stream2=new FileInputStream(f); 
      Bitmap bitmap=BitmapFactory.decodeStream(stream2, null, o2); 
      stream2.close(); 
      return bitmap; 
     } catch (FileNotFoundException e) { 
     } 
     catch (IOException e) { 
      e.printStackTrace(); 
     } 
     return null; 
    } 

    //Task for the queue 
    private class PhotoToLoad 
    { 
     public String url; 
     public ImageView imageView; 
     public PhotoToLoad(String u, ImageView i){ 
      url=u; 
      imageView=i; 
     } 
    } 

    class PhotosLoader implements Runnable { 
     PhotoToLoad photoToLoad; 
     PhotosLoader(PhotoToLoad photoToLoad){ 
      this.photoToLoad=photoToLoad; 
     } 

     @Override 
     public void run() { 
      try{ 
       if(imageViewReused(photoToLoad)) 
        return; 
       Bitmap bmp=getBitmap(photoToLoad.url); 
       memoryCache.put(photoToLoad.url, bmp); 
       if(imageViewReused(photoToLoad)) 
        return; 
       BitmapDisplayer bd=new BitmapDisplayer(bmp, photoToLoad); 
       handler.post(bd); 
      }catch(Throwable th){ 
       th.printStackTrace(); 
      } 
     } 
    } 

    boolean imageViewReused(PhotoToLoad photoToLoad){ 
     String tag=imageViews.get(photoToLoad.imageView); 
     if(tag==null || !tag.equals(photoToLoad.url)) 
      return true; 
     return false; 
    } 

    //Used to display bitmap in the UI thread 
    class BitmapDisplayer implements Runnable 
    { 
     Bitmap bitmap; 
     PhotoToLoad photoToLoad; 
     public BitmapDisplayer(Bitmap b, PhotoToLoad p){bitmap=b;photoToLoad=p;} 
     public void run() 
     { 
      if(imageViewReused(photoToLoad)) 
       return; 
      if(bitmap!=null) 
       photoToLoad.imageView.setImageBitmap(bitmap); 
      else 
       photoToLoad.imageView.setImageResource(stub_id); 
     } 
    } 

    public void clearCache() { 
     memoryCache.clear(); 
     fileCache.clear(); 
    } 

} 

Answer 1

Bitmap _bitmapPreScale = BitmapFactory.decodeStream(buf); 
int oldWidth = _bitmapPreScale.getWidth(); 
int oldHeight = _bitmapPreScale.getHeight(); 
int newWidth = 2592; 
int newHeight = 1936; 

float scaleWidth = ((float) newWidth)/oldWidth; 
float scaleHeight = ((float) newHeight)/oldHeight; 

這可能是一個幫助，你可以訪問下面張貼了一個好。 Save bitmap to location

你會從這裏得到好主意。