AS3 - BitmapData缩略图修复大小

Question

如何使缩略图的尺寸为84x84像素？

function createThumbs()
{
    _myThumbData = new BitmapData(photodefault.width,photodefault.height,false,0xffffff);
    photothumbs.t1.addChild(createBitmap(_myThumbData));
}

function createBitmap(bmd:BitmapData):Bitmap
{
    var bitmap:Bitmap = new Bitmap(bmd);
    bitmap.smoothing = true;
    bitmap.scaleX = bitmap.scaleY = 0.2;
    return bitmap;
}

感谢。 乌利

Answer 1

根据您的评论，您需要调整大小并保持宽高比。 您需要计算原始图像和容器的纵横比，然后根据较大的比例调整容器大小。这就是我的意思：

        function createThumbs()
        {
            _myThumbData = new BitmapData(photodefault.width,photodefault.height,false,0xffffff);
            photothumbs.t1.addChild(createBitmap(_myThumbData));
        }

        function createBitmap(bmd:BitmapData):Bitmap
        {
            var bitmap:Bitmap = new Bitmap(bmd);
            bitmap.smoothing = true;
            setSize(bitmap, bmd.width, bmd.height, 84, 84);
            return bitmap;
        }
        function setSize(target:DisplayObject, contentWidth:Number, contentHeight:Number, targetWidth:Number, targetHeight:Number):void {
            var w:Number = targetWidth;
            var h:Number = targetHeight;
            // maintain aspect ratio
            var containerRatio:Number = targetWidth / targetHeight;
            var imageRatio:Number = contentWidth / contentHeight;
            if (containerRatio < imageRatio) h = w / imageRatio;
            else                             w = h * imageRatio;
            target.width = w;
            target.height = h;
            //centre content - this might change based on your setup
            target.x = (targetWidth - w) * .5;
            target.y = (targetHeight -h) * .5;
        }