ASP.NET上传图片并生成可带版权信息的缩略图

复制代码 代码如下:

  <%@ 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="没有选择文件";

  }

  else

  {

  string path = Server.MapPath("./Uploads/"+uploadFile.PostedFile.FileName.Substring(uploadFile.PostedFile.FileName.LastIndexOf('\\')+1));

  if(File.Exists(path))

  {

  lblErrInfo.Text="已经有同名文件";

  }

  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>

  添加信息:<asp:TextBox id="txtAddInfo" runat="server"> AspxBoy.Com</asp:TextBox>

  </p>

  <p>

  信息位置: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="上传生成所略图" onServerClick="Button_Click" runat="server" />

  </p>

  <p><asp:Image id="ImgPreview" runat="server"></asp:Image>

  </p>

  <!-- Insert content here -->

  </form>

  </body>

  </html>