SubUtils.java 文件源码

public static Bitmap scaleBitmap(Bitmap bitmap, int newWidth, int newHeight) {
    Bitmap scaledBitmap = Bitmap.createBitmap(newWidth, newHeight, Bitmap.Config.ARGB_8888);

    float scaleX = newWidth / (float) bitmap.getWidth();
    float scaleY = newHeight / (float) bitmap.getHeight();
    float pivotX = 0;
    float pivotY = 0;

    Matrix scaleMatrix = new Matrix();
    scaleMatrix.setScale(scaleX, scaleY, pivotX, pivotY);

    Canvas canvas = new Canvas(scaledBitmap);
    canvas.setMatrix(scaleMatrix);
    canvas.drawBitmap(bitmap, 0, 0, new Paint(Paint.FILTER_BITMAP_FLAG));

    return scaledBitmap;
}