我有一个位图采取的Base64字符串从我的远程数据库,(encodedImage是字符串表示图像与Base64):

profileImage = (ImageView)findViewById(R.id.profileImage);

byte[] imageAsBytes=null;
try {
    imageAsBytes = Base64.decode(encodedImage.getBytes());
} catch (IOException e) {e.printStackTrace();}

profileImage.setImageBitmap(
    BitmapFactory.decodeByteArray(imageAsBytes, 0, imageAsBytes.length)
);

profileImage是我的ImageView

但在显示在布局的ImageView中之前,我需要调整图像的大小。我得把它调整到120x120。

有人能告诉我调整大小的代码吗?

我发现的例子不能应用于base64字符串获得位图。


当前回答

缩放位图的目标最大大小和宽度,同时保持纵横比:

int maxHeight = 2000;
int maxWidth = 2000;    
float scale = Math.min(((float)maxHeight / bitmap.getWidth()), ((float)maxWidth / bitmap.getHeight()));

Matrix matrix = new Matrix();
matrix.postScale(scale, scale);

bitmap = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true);

其他回答

import android.graphics.Matrix
public Bitmap getResizedBitmap(Bitmap bm, int newWidth, int newHeight) {
    int width = bm.getWidth();
    int height = bm.getHeight();
    float scaleWidth = ((float) newWidth) / width;
    float scaleHeight = ((float) newHeight) / height;
    // CREATE A MATRIX FOR THE MANIPULATION
    Matrix matrix = new Matrix();
    // RESIZE THE BIT MAP
    matrix.postScale(scaleWidth, scaleHeight);

    // "RECREATE" THE NEW BITMAP
    Bitmap resizedBitmap = Bitmap.createBitmap(
        bm, 0, 0, width, height, matrix, false);
    bm.recycle();
    return resizedBitmap;
}

编辑:根据@aveschini的建议,我添加了bm.recycle();为了避免内存泄漏。请注意,如果您将前一个对象用于其他用途,则应相应地处理。

      Try this kotlin code for resize....Where Max size any size you 
      want

      fun getResizedBitmap(image: Bitmap?, maxSize: Int): Bitmap {
    var width = image!!.width
    var height = image.height
    val bitmapRatio = width.toFloat() / height.toFloat()
     if (bitmapRatio > 0) {
        width = maxSize
        height = (width / bitmapRatio).toInt()
     } else {
        height = maxSize
         width = (height * bitmapRatio).toInt()
     }
         return Bitmap.createScaledBitmap(image, width, height, true)
     }

如果你已经有一个位图,你可以使用下面的代码来调整大小:

Bitmap originalBitmap = <original initialization>;
Bitmap resizedBitmap = Bitmap.createScaledBitmap(
    originalBitmap, newWidth, newHeight, false);

apply Matrix.ScaleToFit.CENTER)获取一个新的位图保持纵横比。

public static Bitmap getScaledwonBitmap(Bitmap srcBmp, int deisredWidth, int desiredHeight) {
        
            Matrix matrix = new Matrix();
            matrix.setRectToRect(new RectF(0, 0, srcBmp.getWidth(), srcBmp.getHeight()),
                    new RectF(0, 0, deisredWidth, desiredHeight),
                    Matrix.ScaleToFit.CENTER);
           return Bitmap.createBitmap(srcBmp, 0, 0, srcBmp.getWidth(), srcBmp.getHeight(), matrix, true);
        
    }
* For resize bitmap with width and height ratio.    

public static Bitmap getResizedBitmap(Bitmap image, int maxSize) {
            int width = image.getWidth();
            int height = image.getHeight();
    
            float bitmapRatio = (float) width / (float) height;
            if (bitmapRatio > 1) {
                width = maxSize;
                height = (int) (width / bitmapRatio);
            } else {
                height = maxSize;
                width = (int) (height * bitmapRatio);
            }
            return Bitmap.createScaledBitmap(image, width, height, true);
        }