等比例图片缩放
1 /// <summary> 2 /// 按比例缩放图片 3 /// </summary> 4 /// <param name="directoryPath"></param> 5 /// <param name="oldFileName"></param> 6 /// <param name="newFileName"></param> 7 /// <param name="zoom"></param> 8 public static void ZoomPic(string directoryPath, string oldFileName, string newFileName, float zoom = 0.7f) 9 { 10 if (Directory.Exists(directoryPath) == false) 11 Directory.CreateDirectory(directoryPath); 12 13 //图片路径 14 var filePath = Path.Combine(directoryPath, oldFileName); 15 try 16 { 17 18 using (FileStream fs = new FileStream(filePath, FileMode.Open, FileAccess.Read)) 19 { 20 System.Drawing.Image image = System.Drawing.Image.FromStream(fs); 21 //重新定义宽和高 22 int width = Convert.ToInt32(image.Width * zoom); 23 int height = Convert.ToInt32(image.Height * zoom); 24 //更新图片大小 25 System.Drawing.Image newImg = new Bitmap(width, height); 26 Graphics g = Graphics.FromImage(newImg); 27 g.DrawImage(image, 0, 0, width, height); 28 //保存新图片 29 newImg.Save(Path.Combine(directoryPath, newFileName)); 30 } 31 } 32 finally 33 { 34 if (File.Exists(filePath)) 35 { 36 File.Delete(filePath); 37 } 38 } 39 }
在此方法中，需要引用 using System.Drawing;
