本文實例講述了C#實現為一張大尺寸圖片創建縮略圖的方法。分享給大家供大家參考。具體實現方法如下:
public static Bitmap CreateThumbnail(string lcFilename, int lnWidth, int lnHeight){ System.Drawing.Bitmap bmpOut = null; try { Bitmap loBMP = new Bitmap(lcFilename); ImageFormat loFormat = loBMP.RawFormat; decimal lnRatio; int lnNewWidth = 0; int lnNewHeight = 0; //*** If the image is smaller than a thumbnail just return it if (loBMP.Width < lnWidth && loBMP.Height < lnHeight) return loBMP; if (loBMP.Width > loBMP.Height) { lnRatio = (decimal)lnWidth / loBMP.Width; lnNewWidth = lnWidth; decimal lnTemp = loBMP.Height * lnRatio; lnNewHeight = (int)lnTemp; } else { lnRatio = (decimal)lnHeight / loBMP.Height; lnNewHeight = lnHeight; decimal lnTemp = loBMP.Width * lnRatio; lnNewWidth = (int)lnTemp; } bmpOut = new Bitmap(lnNewWidth, lnNewHeight); Graphics g = Graphics.FromImage(bmpOut); g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic; g.FillRectangle(Brushes.White, 0, 0, lnNewWidth, lnNewHeight); g.DrawImage(loBMP, 0, 0, lnNewWidth, lnNewHeight); loBMP.Dispose(); } catch { return null; } return bmpOut;}
希望本文所述對大家的C#程序設計有所幫助。
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