private Image GetCropedImage(Image imgSource, int width, int height)
{
bool isSizeChanged = false;
// 計算截圖範圍
int cropWidth = imgSource.Width;
int cropHeight = imgSource.Height;
if (width < imgSource.Width && height < imgSource.Height)
{
if (1.0 * imgSource.Width / width * height <= imgSource.Height)
{
cropHeight = (int)(1.0 * imgSource.Width / width * height);
isSizeChanged = true;
}
else if (1.0 * imgSource.Height / height * width <= imgSource.Width)
{
cropWidth = (int)(1.0 * imgSource.Height / height * width);
isSizeChanged = true;
}
}
else if (width < imgSource.Width && height >= imgSource.Height)
{
cropWidth = (int)(1.0 * imgSource.Height / height * width);
isSizeChanged = true;
}
else if (width >= imgSource.Width && height < imgSource.Height)
{
cropHeight = (int)(1.0 * imgSource.Width / width * height);
isSizeChanged = true;
}
else
{
// 原圖
}
// 進行截圖及縮圖
if (isSizeChanged)
{
var cropedImage = ImageResizer.Crop(imgSource, cropWidth, cropHeight, AnchorPosition.Center);
return(ImageResizer.ScaleByFixedSize(cropedImage, width, height));
}
return(null);
}
private Image GetResizedImage(Image imgSource, int width, int height)
{
// 依比例縮圖
// 計算大小
if (width <= imgSource.Width && height >= (1.0 * imgSource.Height * width / imgSource.Width))
{
height = (int)(1.0 * imgSource.Height * width / imgSource.Width);
}
else if (height <= imgSource.Height && width >= (1.0 * imgSource.Width * height / imgSource.Height))
{
width = (int)(1.0 * imgSource.Width * height / imgSource.Height);
}
// 如果需要縮圖
if (width < imgSource.Width || height < imgSource.Height)
{
return(ImageResizer.ScaleByFixedSize(imgSource, width, height));
}
return(null);
}