C# 怎么修改图片大小

Posted 2023-02-27

    我把图片已经存到了我的电脑上，我知道图片的路径"书籍图片/ xxm.jpg"，用C#怎么改变图片的大小并且覆盖原来的图片呢？    麻烦大虾们帮帮忙。

1、要修改图片大小和动态语言类【c#、asp、jsp】等并无直接关联，而是和html的img标签相关的
2、设置图片大小可以通过直接给img标签的width和height设置固定大小，也可以通过class类，写入样式规则设定大小，如下两种方式：
2-1、<img src="xxx.jpg" width="100" height="100" />
2-2、<img src="xxx.jpg" class="wh100" />
.wh100 width:100px; height:100px; 参考技术A 可以用生成的方式 规定图片大小后 保存为xxm.jpg 放在 书籍图片 文件夹中 就可以了 如果需要生成图片代码 我这里有个 可以给你下
public static string UploadPicture(FileUpload fileUpload, string uploadpath, string tplPath, int readSize)

string str = string.Empty;
string contentType = string.Empty;
string thumbnailPath = string.Empty;
string str4 = string.Empty;
string str5 = string.Empty;
Random random = new Random((int)DateTime.Now.Ticks);
contentType = fileUpload.PostedFile.ContentType;
str = uploadpath + DateTime.Now.Year.ToString() + DateTime.Now.Month.ToString() + DateTime.Now.Day.ToString() + DateTime.Now.Hour.ToString() + DateTime.Now.Minute.ToString() + DateTime.Now.Second.ToString() + random.Next(0x3e8, 0x270f).ToString();
if (fileUpload.PostedFile.ContentLength > 0)

if (contentType == "image/gif")

str5 = ".gif";

else if (contentType == "image/pjpeg")

str5 = ".jpg";

else if (contentType == "image/x-png")

str5 = ".png";

else

return "";

//上传原图
fileUpload.PostedFile.SaveAs(HttpContext.Current.Server.MapPath("../../" + str) + str5);
thumbnailPath = "../../" + str + "_tmp" + str5;
str4 = "../../../" + str + "_mark" + str5;
//上传相关图片
MakeThumbnail("../../" + str + str5, thumbnailPath, 0x58, 0x58, "Cut");
string path = HttpContext.Current.Server.MapPath("../../Template/" + tplPath + "/ImgSize.xml");
XmlDocument document = new XmlDocument();
string xpath = "Picture";
if (File.Exists(path))

document.Load(path);
XmlNode node = document.SelectSingleNode(xpath);
for (int i = 0; i < node.ChildNodes.Count; i++)

string[] strArray = node.ChildNodes[i].SelectSingleNode("@value").Value.Split(new char[] '*' );
//生成缩略图
MakeThumbnail("../../" + str + str5, "../../" + str + "_" + strArray[0] + "-" + strArray[1] + str5, int.Parse(strArray[0]), int.Parse(strArray[1]), "Cut");


return (str + str5);

return "";

这个是单个图片上次 你要修改下本回答被提问者采纳