根据现有Bitmap生成相同图案指定大小的新Bitmap

通过一张现有的Bitmap，画出一张同样的但是大小使我们指定的Bitmap

需求：直接createBitmap的话不允许生成的bitmap的宽高大于原始的，因此需要特定方法来将一张Bitmap的大小进行调整

crossImage为一张现有的bitmap
Bitmap target = Bitmap.createBitmap(MIDDLE_LINE_WIDTH, MIDDLE_LINE_WIDTH, crossImage.getConfig());
Canvas temp_canvas = new Canvas(target);
temp_canvas.drawBitmap(crossImage, null, new Rect(0, 0, target.getWidth(), target.getHeight()), null);
此时的target就是一张指定大小，但是内容和crossImage一样的bitmap了。

//使用Bitmap加Matrix来缩放
public static Drawable resizeImage(Bitmap bitmap, int w, int h)
{
Bitmap BitmapOrg = bitmap;
int width = BitmapOrg.getWidth();
int height = BitmapOrg.getHeight();
int newWidth = w;
int newHeight = h;

    float scaleWidth = ((float) newWidth) / width;  
    float scaleHeight = ((float) newHeight) / height;  

    Matrix matrix = new Matrix();  
    matrix.postScale(scaleWidth, scaleHeight);  
    // if you want to rotate the Bitmap   
    // matrix.postRotate(45);   
    Bitmap resizedBitmap = Bitmap.createBitmap(BitmapOrg, 0, 0, width,  
                    height, matrix, true);  
    return new BitmapDrawable(resizedBitmap);  
}

//使用BitmapFactory.Options的inSampleSize参数来缩放
public static Drawable resizeImage2(String path,
int width,int height)
{
BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;//不加载bitmap到内存中
BitmapFactory.decodeFile(path,options);
int outWidth = options.outWidth;
int outHeight = options.outHeight;
options.inDither = false;
options.inPreferredConfig = Bitmap.Config.ARGB_8888;
options.inSampleSize = 1;

    if (outWidth != 0 && outHeight != 0 && width != 0 && height != 0) 
    {
        int sampleSize=(outWidth/width+outHeight/height)/2;
        Log.d(tag, "sampleSize = " + sampleSize);
        options.inSampleSize = sampleSize;
    }
 
    options.inJustDecodeBounds = false;
    return new BitmapDrawable(BitmapFactory.decodeFile(path, options));     
}