C＃.net - 需要帮助创建缩略图 [英] C# .net - Need help create thumbnail

问题描述

我有一个简单的图像上传脚本我正在使用它重命名图像并将其保存在我服务器上的文件夹中。



但是现在我还需要创建图像的较小版本，重命名并将其保存到同一文件夹。



我是这种编码的新手。我看了很多例子但是无法工作。所以我希望有人可以帮我处理我的代码。





这是我现有的代码： < br $>

<％@ Page Language =   C＃ AutoEventWireup =   True ％>  
 
< html> 
< head> 
< script language =   C＃ runat =   server> 
  //  上传新文件名称的原始图片 
  void  Button1_Click（object Source，EventArgs e）{
 string id = Request.QueryString [  ID]; 
 Response.Write（id）; 
  if （File1.PostedFile！=  null ）{
  try  {
 File1.PostedFile.SaveAs（Server.MapPath（ 上传//）+   big + id +  。jpg）; 
 Span1.InnerHtml =  文件上传成功： +   big + id +   .JPG; 
} 
  catch （Exception exc）{
 Span1.InnerHtml =  保存文件时出错 +   big + id +  。jpg +   + exc.ToString（）; 
} 
 
} 
 
} 
< / script> 
 < /   head  >  
< body> 
< form enctype =   multipart / form-data runat =   server> 
< p>要上传的文件：
< input id =   File1 type =   file runat =   server> 
< br> 
< input type = button id =   Button1 value =  上传önServerClick=   Button1_Click runat =   server> 
 < /   br  >  < /   p  >  
< p>< span id = Span1 style =   font：8pt verdana; runat =   server /> < /   p  >  
 < ; /  表格 >  
 < /   body  >  
 < /   html  >  

解决方案

  protected   void  UploadBtn_Click（ object  sender，EventArgs e）
 {
  if （FileUpload1.HasFile）
 {
 FileUpload1.SaveAs（MapPath（ 〜/ Image / + FileUpload1.FileName））; 
 System.Drawing.Image img1 = System.Drawing.Image.FromFile（MapPath（ 〜/ Image / ）+ FileUpload1.FileName）; 
 
 System.Drawing.Image bmp1 = img1.GetThumbnailImage（ 75 ， 75  ， null ， IntPtr  .Zero）; 
 bmp1.Save（MapPath（ 〜/ Thumbnail /）+ FileUpload1.FileName） ; 
 ThumbnailImage.ImageUrl =  〜/ Thumbnail / + FileUpload1.FileName; 
 
} 
} 

我使用过GetThumbnailImage方法Image类的。这个方法返回给定原始图像的缩略图。这可能是我想用缩略图得到的最佳图像质量。

我试过但是我做错了，因为它不工作。



对不起，我很陌生。





这是我的代码：

 <％@     Page    语言  =  C＃    AutoEventWireup   =  True   ％>  
 
  <   h tml  >  
 <   head  >  
 <   script     language   =  C＃    runat   = 服务器 >  
 < span class =code-comment> //  上传新文件名称的原始图片 
  void  Button1_Click（ object  Source，EventArgs e）{
  string  id = Request .QueryString [  id]; 
 Response.Write（id）; 
  if （File1.PostedFile！=  null ）{
  try  {
 File1.PostedFile.SaveAs（Server.MapPath（ 上传//）+   big + id +  。jpg）; 
 Span1.InnerHtml =  文件上传成功： +   big + id +   .JPG; 
 
 System.Drawing.Image img1 = System.Drawing.Image.FromFile（Server.MapPath（ 上传//）+   big + id +  。jpg）; 
 
 System.Drawing.Image bmp1 = img1.GetThumbnailImage（ 116 ， 82  ， null ， IntPtr  .Zero）; 
 bmp1.Save（MapPath（  uploads //）+   small + id +   JPG）; 
 ThumbnailImage.ImageUrl =   uploads // +   small + id +   .JPG; 
} 
  catch （Exception exc）{
 Span1.InnerHtml =  保存文件时出错 +   big + id +  。jpg +   + exc.ToString（）; 
} 
 
} 
 
} 
 < /   script  >  
 <   / head  >  
 <  正文 >  
 <   form     enctype   =  multipart / form-data    runat   = 服务器 > ;  
 <   p   > 要上传的文件：
 <  输入    id   =  File1    type   =  file    runat   = 服务器 >  
 <   br  >  
 <   input    类型  =  按钮  id   =  Button1    value   = 上传    OnServerClick   =  Button1_Click    runat   =  server >  
 <   / p  >  
 <   p  >  <   span     id   =   Span1   style   =  font：8pt verdana;    runat   =  server    /  >  <   / p  >  
 <   / form  >  
 < span class =code-keyword><   / body  >  
 <   / html  >  

这是我得到的错误：





编译器错误消息：CS0103：当前上下文中不存在名称'ThumbnailImage'

刚刚删除了有问题的行，似乎工作。



这是我的工作代码，任何人都有兴趣：

 <％@     Page    语言  =  C＃    AutoEventWireup   =  True   ％>  
 
 <   html  >  
 <  < span class =code-leadattribute> head  >  
 <   script     language   =  C＃    runat   =  server >  
  //  上传新文件名称的原始图片 
  void  Button1_Click（ object  Source，EventArgs e）{
  string  id = Request.QueryString [  ID]; 
 Response.Write（id）; 
  if （File1.PostedFile！=  null ）{
  try  {
 File1.PostedFile.SaveAs（Server.MapPath（ 上传//）+   big + id +  。jpg）; 
 Span1.InnerHtml =  文件上传成功： +   big + id +   .JPG; 
 
 System.Drawing.Image img1 = System.Drawing.Image.FromFile（Server.MapPath（ 上传//）+   big + id +  。jpg）; 
 
 System.Drawing.Image bmp1 = img1.GetThumbnailImage（ 116 ， 82  ， null ， IntPtr  .Zero）; 
 bmp1.Save（Server.MapPath（  uploads //）+   small + id +   JPG）; 
  //   ThumbnailImage.ImageUrl =uploads //+small+ id +。jpg;  
} 
  catch （Exception exc）{
 Span1.InnerHtml =  保存文件时出错 +   big + id +  。jpg +   + exc.ToString（）; 
} 
 
} 
 
} 
 < /   script  >  
 <   / head  >  
 <  正文 >  
 <   form     enctype   =  multipart / form-data    runat   = 服务器 > ;  
 <   p   > 要上传的文件：
 <  输入    id   =  File1    type   =  file    runat   = 服务器 >  
 <   br  >  
 <   input    类型  =  按钮  id   =  Button1    value   = 上传    OnServerClick   =  Button1_Click    runat   =  server >  
 <   / p  >  
 <   p  >  <   span     id   =   Span1   style   =  font：8pt verdana;    runat   =  server    /  >  <   / p  >  
 <   / form  >  
 < span class =code-keyword><   / body  >  
 <   / html  >  

I have a simple image upload script I am using that renames the images and saves it in a folder on my server.

But now I need to also create a smaller version of the image, rename it and save it to the same folder.

I'm new to this kind of coding. I have looked at lots of examples but am unable to get any to work. So I was hoping someone could help me with my code.


Here is my existing code:

<%@ Page Language="C#" AutoEventWireup="True" %>

<html>
<head>
<script language="C#"  runat="server">
// UPLOAD ORIGINAL IMAGE WITH NEW FILE NAME
void Button1_Click(object Source, EventArgs e){
string id = Request.QueryString["id"];
Response.Write (id);
    if (File1.PostedFile != null){
        try{
            File1.PostedFile.SaveAs(Server.MapPath("uploads//")+"big"+id+".jpg");
            Span1.InnerHtml = "File uploaded successfully: "+"big"+id+".jpg";
        }
        catch (Exception exc){
            Span1.InnerHtml = "Error saving file" + "big"+id+".jpg" + "" + exc.ToString();
        }
		
    }
	
}
</script>
</head>
<body>
<form enctype="multipart/form-data"  runat="server">
  <p>File to Upload: 
    <input id="File1" type="file"  runat="server">
    <br>
    <input type=button id="Button1" value="Upload"  önServerClick="Button1_Click"  runat="server">
</br></p>
  <p><span id=Span1 style="font: 8pt verdana;"  runat="server" /></p>
</form>
</body>
</html>

解决方案

protected void UploadBtn_Click(object sender, EventArgs e)
    {
        if (FileUpload1.HasFile)
        {
            FileUpload1.SaveAs(MapPath("~/Image/" + FileUpload1.FileName));
            System.Drawing.Image img1 = System.Drawing.Image.FromFile(MapPath("~/Image/") + FileUpload1.FileName);
 
            System.Drawing.Image bmp1 = img1.GetThumbnailImage(75, 75, null, IntPtr.Zero);
            bmp1.Save(MapPath("~/Thumbnail/") + FileUpload1.FileName);
            ThumbnailImage.ImageUrl = "~/Thumbnail/" + FileUpload1.FileName;
           
        }
    }

I have used GetThumbnailImage method of the Image class. This method returns the thumbnail image for the given original image.This could be the best picture quality we can derive with thumbnail i guess.

I tried that but I'm doing something wrong as its not working.

Sorry but i'm really new to this.


Here is my code:

<%@ Page Language="C#" AutoEventWireup="True" %>

<html>
<head>
<script language="C#" runat="server">
// UPLOAD ORIGINAL IMAGE WITH NEW FILE NAME
void Button1_Click(object Source, EventArgs e){
string id = Request.QueryString["id"];
Response.Write (id);
    if (File1.PostedFile != null){
        try{
            File1.PostedFile.SaveAs(Server.MapPath("uploads//")+"big"+id+".jpg");
            Span1.InnerHtml = "File uploaded successfully: "+"big"+id+".jpg";

            System.Drawing.Image img1 = System.Drawing.Image.FromFile(Server.MapPath("uploads//")+"big"+id+".jpg");

            System.Drawing.Image bmp1 = img1.GetThumbnailImage(116, 82, null, IntPtr.Zero);
            bmp1.Save(MapPath("uploads//")+"small"+id+".jpg");
            ThumbnailImage.ImageUrl = "uploads//"+"small"+id+".jpg";
        }
        catch (Exception exc){
            Span1.InnerHtml = "Error saving file" + "big"+id+".jpg" + "" + exc.ToString();
        }

    }

}
</script>
</head>
<body>
<form enctype="multipart/form-data" runat="server">
  <p>File to Upload:
    <input id="File1" type="file" runat="server">
    <br>
    <input type=button id="Button1" value="Upload" OnServerClick="Button1_Click" runat="server">
</p>
  <p><span id=Span1 style="font: 8pt verdana;" runat="server" /></p>
</form>
</body>
</html>

Here is the error i'm getting:


Compiler Error Message: CS0103: The name 'ThumbnailImage' does not exist in the current context

Just removed the offending line and it seems to be working.

Here is my working code incase anyone is interested:

<%@ Page Language="C#" AutoEventWireup="True" %>

<html>
<head>
<script language="C#" runat="server">
// UPLOAD ORIGINAL IMAGE WITH NEW FILE NAME
void Button1_Click(object Source, EventArgs e){
string id = Request.QueryString["id"];
Response.Write (id);
    if (File1.PostedFile != null){
        try{
            File1.PostedFile.SaveAs(Server.MapPath("uploads//")+"big"+id+".jpg");
            Span1.InnerHtml = "File uploaded successfully: "+"big"+id+".jpg";

            System.Drawing.Image img1 = System.Drawing.Image.FromFile(Server.MapPath("uploads//")+"big"+id+".jpg");

            System.Drawing.Image bmp1 = img1.GetThumbnailImage(116, 82, null, IntPtr.Zero);
            bmp1.Save(Server.MapPath("uploads//")+"small"+id+".jpg");
            //ThumbnailImage.ImageUrl = "uploads//"+"small"+id+".jpg";
        }
        catch (Exception exc){
            Span1.InnerHtml = "Error saving file" + "big"+id+".jpg" + "" + exc.ToString();
        }

    }

}
</script>
</head>
<body>
<form enctype="multipart/form-data" runat="server">
  <p>File to Upload:
    <input id="File1" type="file" runat="server">
    <br>
    <input type=button id="Button1" value="Upload" OnServerClick="Button1_Click" runat="server">
</p>
  <p><span id=Span1 style="font: 8pt verdana;" runat="server" /></p>
</form>
</body>
</html>

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