圖片縮放轉換類

在處理圖片顯示的時候，我們經常會用到圖片的縮放功能。

    /// <summary>
    /// 圖片大小規格變換工具
    /// </summary>
    public sealed class ZoomPicture
    {
        /// <summary>
        /// 縮放圖片
        /// </summary>
        /// <param name="srcPicPath">來源圖片文件完整路徑</param>
        /// <param name="tagPicPath">目標圖片文件完整路徑</param>
        /// <param name="width">目標圖片寬度</param>
        /// <param name="height">目標圖片高度</param>
        public static void SmallPicture(string srcPicPath, string tagPicPath, int width, int height)
        {
            System.Drawing.Bitmap objPic, objNewPic;
            try
            {
                objPic = new System.Drawing.Bitmap(srcPicPath);
                objNewPic = new System.Drawing.Bitmap(objPic, width, height);
                objNewPic.Save(tagPicPath);
            }
            catch (Exception exp)
            {
                throw exp;
            }
            finally
            {
                objPic = null;
                objNewPic = null;
            }
        }

        /// <summary>
        /// 按比例縮放圖片
        /// </summary>
        /// <param name="srcPicPath">來源圖片文件完整路徑</param>
        /// <param name="tagPicPath">目標圖片文件完整路徑</param>
        /// <param name="proportion">縮小比例0～100</param>
        public static void SmallPicture(string srcPicPath, string tagPicPath, int proportion)
        {

            System.Drawing.Bitmap objPic, objNewPic;
            try
            {
                objPic = new System.Drawing.Bitmap(srcPicPath);
                int width = objPic.Width * proportion / 100;
                int intHeight = (width / objPic.Width) * objPic.Height;
                objNewPic = new System.Drawing.Bitmap(objPic, width, intHeight);
                objNewPic.Save(tagPicPath);

            }
            catch (Exception exp)
            {
                throw exp;
            }
            finally
            {
                objPic = null;
                objNewPic = null;
            }
        }

        /// <summary>
        /// 按寬度比例縮放圖片，自動計算高度
        /// </summary>
        /// <param name="srcPicPath">來源圖片文件完整路徑</param>
        /// <param name="tagPicPath">目標圖片文件完整路徑</param>
        /// <param name="intWidth">目標圖片寬度</param>
        public static void SmallPictureForWidth(string srcPicPath, string tagPicPath, int intWidth)
        {

            System.Drawing.Bitmap objPic, objNewPic;
            try
            {
                objPic = new System.Drawing.Bitmap(srcPicPath);
                int intHeight = (intWidth / objPic.Width) * objPic.Height;
                objNewPic = new System.Drawing.Bitmap(objPic, intWidth, intHeight);
                objNewPic.Save(srcPicPath);

            }
            catch (Exception exp)
            {
                throw exp;
            }
            finally
            {
                objPic = null;
                objNewPic = null;
            }
        }

        /// <summary>
        /// 按高度比例縮放圖片，自動計算寬度
        /// </summary>
        /// <param name="srcPicPath">來源圖片文件完整路徑</param>
        /// <param name="tagPicPath">目標圖片文件完整路徑</param>
        /// <param name="intHeight">目標圖片高度</param>
        public static void SmallPictureForHeight(string srcPicPath, string tagPicPath, int intHeight)
        {

            System.Drawing.Bitmap objPic, objNewPic;
            try
            {
                objPic = new System.Drawing.Bitmap(srcPicPath);
                int intWidth = (intHeight / objPic.Height) * objPic.Width;
                objNewPic = new System.Drawing.Bitmap(objPic, intWidth, intHeight);
                objNewPic.Save(tagPicPath);

            }
            catch (Exception exp)
            {
                throw exp;
            }
            finally
            {
                objPic = null;
                objNewPic = null;
            }
        }

    }