求计算同比缩略图长宽的函数

[我是翔子]

原图长宽：

int Source_Width;
int Source_Height;

缩略图画板的长宽：

int Board_Width;
int Board_Height;

缩略图的长宽：

int Small_Width;
int Small_Height;

根据原图的长宽，和缩略图画板的长宽，计算出同比缩略图的长宽，谢谢

[我是翔子]

怎么没人啦

[zgke]

public Size GetThumbnailSize(Size p_SourceSize, Size p_BoardSize)
{
decimal _Width =(decimal) p_BoardSize.Width / p_SourceSize.Width;
decimal _Height = (decimal)p_BoardSize.Height / p_SourceSize.Height;
decimal _Factor = _Width;
if (_Height < _Width) _Factor = _Height;
return new Size((int)(p_SourceSize.Width * _Factor), (int)(p_SourceSize.Height * _Factor));
}

这样？ 同比例的。 如果你要定一个宽或则高 自己改把。

[lester19872007]

/// <summary>
        /// 生成缩略图
        /// </summary>
        /// <param name="originalImagePath">源图路径（物理路径）</param>
        /// <param name="thumbnailPath">缩略图路径（物理路径）</param>
        /// <param name="width">缩略图宽度</param>
        /// <param name="height">缩略图高度</param>
        /// <param name="mode">生成缩略图的方式</param>    
        public static void MakeThumbnail(string originalImagePath, string thumbnailPath, int width, int height, string mode)
        {
            Image originalImage = Image.FromFile(originalImagePath);

            int towidth = width;
            int toheight = height;

            int x = 0;
            int y = 0;
            int ow = originalImage.Width;
            int oh = originalImage.Height;

            switch (mode)
            {
                case "HW"://指定高宽缩放（可能变形）                
                    break;
                case "W"://指定宽，高按比例                    
                    toheight = originalImage.Height * width / originalImage.Width;
                    break;
                case "H"://指定高，宽按比例
                    towidth = originalImage.Width * height / originalImage.Height;
                    break;
                case "Cut"://指定高宽裁减（不变形）                
                    if ((double)originalImage.Width / (double)originalImage.Height > (double)towidth / (double)toheight)
                    {
                        oh = originalImage.Height;
                        ow = originalImage.Height * towidth / toheight;
                        y = 0;
                        x = (originalImage.Width - ow) / 2;
                    }
                    else
                    {
                        ow = originalImage.Width;
                        oh = originalImage.Width * height / towidth;
                        x = 0;
                        y = (originalImage.Height - oh) / 2;
                    }
                    break;
                default:
                    break;
            }