ASP.NET uploads images and generates thumbnails with copyright information

  • 2020-05-05 11:05:30
  • OfStack


<%@ Page Language="C#" ResponseEncoding="gb2312" %> 
<%@ import Namespace="System" %> 
<%@ import Namespace="System.IO" %> 
<%@ import Namespace="System.Drawing" %> 
<%@ import Namespace="System.Drawing.Imaging" %> 
<script runat="server">  
   

void Page_Load(Object sender, EventArgs e) 
{ 
if(!Page.IsPostBack) 
{ 
ImgPreview.Visible=false; 
} 
} 
void GetThumbnailImage(int width,int height,string strInfo,int left,int right) 
{ 
string file="Uploads/"+uploadFile.PostedFile.FileName.Substring(uploadFile.PostedFile.FileName.LastIndexOf('\\')+1); 
string newfile="Uploads/"+uploadFile.PostedFile.FileName.Substring(uploadFile.PostedFile.FileName.LastIndexOf('\\')+1)+".jpg"; 
string strAdd=strInfo; 
System.Drawing.Image oldimage = System.Drawing.Image.FromFile(Server.MapPath(file)); 
System.Drawing.Image thumbnailImage = 
oldimage.GetThumbnailImage(width, height,new System.Drawing.Image.GetThumbnailImageAbort(ThumbnailCallback), IntPtr.Zero); 
Response.Clear(); 
Bitmap output=new Bitmap(thumbnailImage); 
Graphics g=Graphics.FromImage(output); 
g.DrawString(strAdd,new Font("Courier New", 14),new SolidBrush(Color.Red),left,right); 
output.Save(Server.MapPath(newfile),System.Drawing.Imaging.ImageFormat.Jpeg); 
Response.ContentType = "image/gif"; 
ImgPreview.Visible=true; 
ImgPreview.ImageUrl=newfile; 
} 
bool ThumbnailCallback() 
{ 
return true; 
} 

void Button_Click(object sender, EventArgs e) 
{ 
int width,height,left,right; 
string strAddInfo=txtAddInfo.Text; 
width=Int32.Parse(txtWidth.Text); 
height=Int32.Parse(txtHeight.Text); 
left=Int32.Parse(txtLeft.Text); 
right=Int32.Parse(txtRight.Text); 
if(!(uploadFile.PostedFile.ContentLength>0)) 
{ 
lblErrInfo.Text=" No selected file "; 
} 
else 
{ 

string path = Server.MapPath("./Uploads/"+uploadFile.PostedFile.FileName.Substring(uploadFile.PostedFile.FileName.LastIndexOf('\\')+1)); 
if(File.Exists(path)) 
{ 
lblErrInfo.Text=" You already have a file with the same name "; 
} 
else 
{ 
uploadFile.PostedFile.SaveAs(path); 
GetThumbnailImage(width,height,strAddInfo,left,right); 
} 
} 
} 
</script> 
<html> 
<head> 
</head> 
<body> 
<form method="post" enctype="multipart/form-data" runat="server"> 
<p> 
<input id="uploadFile" type="file" runat="server" /> 
<asp:Label id="lblErrInfo" runat="server" forecolor="Red"></asp:Label> 
</p> 
<p> 
width:<asp:TextBox id="txtWidth" runat="server" Width="40px">100</asp:TextBox> 
height:<asp:TextBox id="txtHeight" runat="server" Width="40px">150</asp:TextBox> 

</p> 
<p> 
 Add information: <asp:TextBox id="txtAddInfo" runat="server"> AspxBoy.Com</asp:TextBox> 
</p> 
<p> 
 Information location: left:<asp:TextBox id="txtLeft" runat="server" Width="40px">10</asp:TextBox> 
right:<asp:TextBox id="txtRight" runat="server" Width="40px">135</asp:TextBox> 
</p> 
<p> 

<input id="button" type="button" value=" Upload generated sketch " onServerClick="Button_Click" runat="server" /> 
</p> 
<p><asp:Image id="ImgPreview" runat="server"></asp:Image> 
</p> 
<!-- Insert content here --> 
</form> 
</body> 
</html> 

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