用户将能够上载图像。如果图像大于设置的大小,我想将其缩小到该大小。显然,它不必完全匹配由于比率,宽度将是关键大小,所以高度将是可变的。
如果图像小于设置的大小,我想创建一个新的图像到设置的大小与一个定义的颜色背景,然后将上传的图像中心,因此,结果是原始的填充颜色。
非常感谢任何代码示例或链接
最佳答案
下面是一段代码,我很快根据宽度调整了大小。我相信你能想出如何在位图中添加背景色。这不是完整的代码,只是一个如何做事的想法。
public static void ResizeLogo(string originalFilename, string resizeFilename)
{
Image imgOriginal = Image.FromFile(originalFilename);
//pass in whatever value you want for the width (180)
Image imgActual = ScaleBySize(imgOriginal, 180);
imgActual.Save(resizeFilename);
imgActual.Dispose();
}
public static Image ScaleBySize(Image imgPhoto, int size)
{
int logoSize = size;
float sourceWidth = imgPhoto.Width;
float sourceHeight = imgPhoto.Height;
float destHeight = 0;
float destWidth = 0;
int sourceX = 0;
int sourceY = 0;
int destX = 0;
int destY = 0;
// Resize Image to have the height = logoSize/2 or width = logoSize.
// Height is greater than width, set Height = logoSize and resize width accordingly
if (sourceWidth > (2 * sourceHeight))
{
destWidth = logoSize;
destHeight = (float)(sourceHeight * logoSize / sourceWidth);
}
else
{
int h = logoSize / 2;
destHeight = h;
destWidth = (float)(sourceWidth * h / sourceHeight);
}
// Width is greater than height, set Width = logoSize and resize height accordingly
Bitmap bmPhoto = new Bitmap((int)destWidth, (int)destHeight,
PixelFormat.Format32bppPArgb);
bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);
Graphics grPhoto = Graphics.FromImage(bmPhoto);
grPhoto.InterpolationMode = InterpolationMode.HighQualityBicubic;
grPhoto.DrawImage(imgPhoto,
new Rectangle(destX, destY, (int)destWidth, (int)destHeight),
new Rectangle(sourceX, sourceY, (int)sourceWidth, (int)sourceHeight),
GraphicsUnit.Pixel);
grPhoto.Dispose();
return bmPhoto;
}