Hi, I need some help here. Right now, I'm stuck at this function

Logic: check if image already existed when uploading, if yes, ask user for input yes/no, if yes overwrite, if no, change a new filename.

This is my upload.aspx

1    using System;
2    using System.IO;
3    using System.Collections;
4    using System.ComponentModel;
5    using System.Data;
6    using System.Drawing;
7    using System.Web;
8    using System.Web.SessionState;
9    using System.Web.UI;
10   using System.Web.UI.WebControls;
11   using System.Web.UI.HtmlControls;
12   
13   
14   namespace netimageupload
15   {
16       /// <summary>
17       /// Summary description for WebForm1.
18       /// </summary>
19       public partial class WebForm1 : System.Web.UI.Page
20       {
21           // protected System.Web.UI.HtmlControls.HtmlInputFile filUpload;
22           // protected System.Web.UI.WebControls.Image imgPicture;
23           // protected System.Web.UI.WebControls.Label lblOutput;
24           // protected System.Web.UI.WebControls.Button btnUpload;
25   
26           private void Page_Load(object sender, System.EventArgs e)
27           {
28               // Put user code to initialize the page here
29           }
30   
31           #region Web Form Designer generated code
32           override protected void OnInit(EventArgs e)
33           {
34               //
35               // CODEGEN: This call is required by the ASP.NET Web Form Designer.
36               //
37               InitializeComponent();
38               base.OnInit(e);
39           }
40   
41           /// <summary>
42           /// Required method for Designer support - do not modify
43           /// the contents of this method with the code editor.
44           /// </summary>
45           private void InitializeComponent()
46           {
47               this.btnUpload.Click += new System.EventHandler(this.btnUpload_Click);
48               this.Load += new System.EventHandler(this.Page_Load);
49   
50           }
51           #endregion
52   
53           private void btnUpload_Click(object sender, System.EventArgs e)
54           {
55               // Initialize variables
56               string sSavePath;
57               string sThumbExtension;
58               int intThumbWidth;
59               int intThumbHeight;
60   
61               // Set constant values
62               sSavePath = "images/Saved Images/";
63               sThumbExtension = "_thumb";
64               intThumbWidth = 160;
65               intThumbHeight = 120;
66   
67   
68   
69               // If file field isn’t empty
70               if (filUpload.PostedFile != null)
71               {
72                   // Check file size (mustn’t be 0)
73                   HttpPostedFile myFile = filUpload.PostedFile;
74                   int nFileLen = myFile.ContentLength;
75                   if (nFileLen == 0)
76                   {
77                       lblOutput.Text = "There wasn't any file uploaded.";
78                       return;
79                   }
80   
81                   // Check file extension (must be JPG)
82                   if (System.IO.Path.GetExtension(myFile.FileName).ToLower() != ".jpg")
83                   {
84                       lblOutput.Text = "The file must have an extension of JPG";
85                       return;
86                   }
87   
88                   // Read file into a data stream
89                   byte[] myData = new Byte[nFileLen];
90                   myFile.InputStream.Read(myData, 0, nFileLen);
91   
92                   // Make sure a duplicate file doesn’t exist.  If it does, keep on appending an incremental numeric until it is unique
93                   string sFilename = System.IO.Path.GetFileName(myFile.FileName);
94                   string ans;
95                   int file_append = 0;
96   
97                   if (System.IO.File.Exists(Server.MapPath(sSavePath + sFilename)))
98                   {
99                       Response.Write("&lt;script type=\"text/javascript\"&gt;var result = confirm('Image already existed. Click OK to overwrite. Click NO for new filename.')</script>");
100                     
101                  }
102  
103                  // Save the stream to disk
104                  System.IO.FileStream newFile = new System.IO.FileStream(Server.MapPath(sSavePath + sFilename), System.IO.FileMode.Create);
105                  newFile.Write(myData, 0, myData.Length);
106                  newFile.Close();
107                  TextWriter tw = new StreamWriter(Server.MapPath("Images/Saved Images/" + sFilename + ".html"));
108  
109                  // write a line of text to the files
110                  tw.WriteLine("&lt;html");
111                  tw.WriteLine("&lt;img src=\"" + sSavePath + sFilename + "\"&gt;" + " " + "&lt;desc=\"" + desc.Text + "\"&gt;" + " " + "&lt;mat=\"" + materials.Text + "\"&gt;" + " " + "&lt;date=\"" + date.Text + "\"&gt;");
112                  tw.WriteLine("&lt;/html>");
113  
114                  // close the stream
115                  tw.Close();
116  
117  
118                  // Check whether the file is really a JPEG by opening it
119                  System.Drawing.Image.GetThumbnailImageAbort myCallBack = new System.Drawing.Image.GetThumbnailImageAbort(ThumbnailCallback);
120                  Bitmap myBitmap;
121                  try
122                  {
123                      myBitmap = new Bitmap(Server.MapPath(sSavePath + sFilename));
124  
125                      // If jpg file is a jpeg, create a thumbnail filename that is unique.
126                      file_append = 0;
127                      string sThumbFile = System.IO.Path.GetFileNameWithoutExtension(myFile.FileName) + sThumbExtension + ".jpg";
128                      while (System.IO.File.Exists(Server.MapPath(sSavePath + sThumbFile)))
129                      {
130                          file_append++;
131                          sThumbFile = System.IO.Path.GetFileNameWithoutExtension(myFile.FileName) + file_append.ToString() + sThumbExtension + ".jpg";
132                      }
133  
134                      // Save thumbnail and output it onto the webpage
135                      System.Drawing.Image myThumbnail = myBitmap.GetThumbnailImage(intThumbWidth, intThumbHeight, myCallBack, IntPtr.Zero);
136                      myThumbnail.Save(Server.MapPath(sSavePath + sThumbFile));
137                      imgPicture.ImageUrl = sSavePath + sThumbFile;
138  
139  
140                      // Displaying success information
141                      lblOutput.Text = "File uploaded successfully!";
142  
143  
144                      // Destroy objects
145                      myThumbnail.Dispose();
146                      myBitmap.Dispose();
147                  }
148                  catch (ArgumentException errArgument)
149                  {
150                      // The file wasn't a valid jpg file
151                      lblOutput.Text = "The file wasn't a valid jpg file.";
152                      System.IO.File.Delete(Server.MapPath(sSavePath + sFilename));
153                  }
154              }
155          }
156  
157          public bool ThumbnailCallback()
158          {
159              return false;
160          }
161          protected void btnUpload_Click1(object sender, EventArgs e)
162          {
163  
164          }
165          protected void txtFName_TextChanged(object sender, EventArgs e)
166          {
167  
168          }
169          protected void btnUpload_Click2(object sender, EventArgs e)
170          {
171  
172          }
173  }
174  }
175  using System;
176  using System.IO;
177  using System.Collections;
178  using System.ComponentModel;
179  using System.Data;
180  using System.Drawing;
181  using System.Web;
182  using System.Web.SessionState;
183  using System.Web.UI;
184  using System.Web.UI.WebControls;
185  using System.Web.UI.HtmlControls;
186  
187  
188  namespace netimageupload
189  {
190      /// <summary>
191      /// Summary description for WebForm1.
192      /// </summary>
193      public partial class WebForm1 : System.Web.UI.Page
194      {
195          // protected System.Web.UI.HtmlControls.HtmlInputFile filUpload;
196          // protected System.Web.UI.WebControls.Image imgPicture;
197          // protected System.Web.UI.WebControls.Label lblOutput;
198          // protected System.Web.UI.WebControls.Button btnUpload;
199  
200          private void Page_Load(object sender, System.EventArgs e)
201          {
202              // Put user code to initialize the page here
203          }
204  
205          #region Web Form Designer generated code
206          override protected void OnInit(EventArgs e)
207          {
208              //
209              // CODEGEN: This call is required by the ASP.NET Web Form Designer.
210              //
211              InitializeComponent();
212              base.OnInit(e);
213          }
214  
215          /// <summary>
216          /// Required method for Designer support - do not modify
217          /// the contents of this method with the code editor.
218          /// </summary>
219          private void InitializeComponent()
220          {
221              this.btnUpload.Click += new System.EventHandler(this.btnUpload_Click);
222              this.Load += new System.EventHandler(this.Page_Load);
223  
224          }
225          #endregion
226  
227          private void btnUpload_Click(object sender, System.EventArgs e)
228          {
229              // Initialize variables
230              string sSavePath;
231              string sThumbExtension;
232              int intThumbWidth;
233              int intThumbHeight;
234  
235              // Set constant values
236              sSavePath = "images/Saved Images/";
237              sThumbExtension = "_thumb";
238              intThumbWidth = 160;
239              intThumbHeight = 120;
240  
241  
242  
243              // If file field isn’t empty
244              if (filUpload.PostedFile != null)
245              {
246                  // Check file size (mustn’t be 0)
247                  HttpPostedFile myFile = filUpload.PostedFile;
248                  int nFileLen = myFile.ContentLength;
249                  if (nFileLen == 0)
250                  {
251                      lblOutput.Text = "There wasn't any file uploaded.";
252                      return;
253                  }
254  
255                  // Check file extension (must be JPG)
256                  if (System.IO.Path.GetExtension(myFile.FileName).ToLower() != ".jpg")
257                  {
258                      lblOutput.Text = "The file must have an extension of JPG";
259                      return;
260                  }
261  
262                  // Read file into a data stream
263                  byte[] myData = new Byte[nFileLen];
264                  myFile.InputStream.Read(myData, 0, nFileLen);
265  
266                  // Make sure a duplicate file doesn’t exist.  If it does, keep on appending an incremental numeric until it is unique
267                  string sFilename = System.IO.Path.GetFileName(myFile.FileName);
268                  string ans;
269                  int file_append = 0;
270  
271                  if (System.IO.File.Exists(Server.MapPath(sSavePath + sFilename)))
272                  {
273                      Response.Write("&lt;script type=\"text/javascript\"&gt;var result = confirm('Image already existed. Click OK to overwrite. Click NO for new filename.')</script>");
274  
275                  }
276  
277                  // Save the stream to disk
278                  System.IO.FileStream newFile = new System.IO.FileStream(Server.MapPath(sSavePath + sFilename), System.IO.FileMode.Create);
279                  newFile.Write(myData, 0, myData.Length);
280                  newFile.Close();
281                  TextWriter tw = new StreamWriter(Server.MapPath("Images/Saved Images/" + sFilename + ".html"));
282  
283                  // write a line of text to the files
284                  tw.WriteLine("&lt;html");
285                  tw.WriteLine("&lt;img src=\"" + sSavePath + sFilename + "\"&gt;" + " " + "&lt;desc=\"" + desc.Text + "\"&gt;" + " " + "&lt;mat=\"" + materials.Text + "\"&gt;" + " " + "&lt;date=\"" + date.Text + "\"&gt;");
286                  tw.WriteLine("&lt;/html>");
287  
288                  // close the stream
289                  tw.Close();
290  
291  
292                  // Check whether the file is really a JPEG by opening it
293                  System.Drawing.Image.GetThumbnailImageAbort myCallBack = new System.Drawing.Image.GetThumbnailImageAbort(ThumbnailCallback);
294                  Bitmap myBitmap;
295                  try
296                  {
297                      myBitmap = new Bitmap(Server.MapPath(sSavePath + sFilename));
298  
299                      // If jpg file is a jpeg, create a thumbnail filename that is unique.
300                      file_append = 0;
301                      string sThumbFile = System.IO.Path.GetFileNameWithoutExtension(myFile.FileName) + sThumbExtension + ".jpg";
302                      while (System.IO.File.Exists(Server.MapPath(sSavePath + sThumbFile)))
303                      {
304                          file_append++;
305                          sThumbFile = System.IO.Path.GetFileNameWithoutExtension(myFile.FileName) + file_append.ToString() + sThumbExtension + ".jpg";
306                      }
307  
308                      // Save thumbnail and output it onto the webpage
309                      System.Drawing.Image myThumbnail = myBitmap.GetThumbnailImage(intThumbWidth, intThumbHeight, myCallBack, IntPtr.Zero);
310                      myThumbnail.Save(Server.MapPath(sSavePath + sThumbFile));
311                      imgPicture.ImageUrl = sSavePath + sThumbFile;
312  
313  
314                      // Displaying success information
315                      lblOutput.Text = "File uploaded successfully!";
316  
317  
318                      // Destroy objects
319                      myThumbnail.Dispose();
320                      myBitmap.Dispose();
321                  }
322                  catch (ArgumentException errArgument)
323                  {
324                      // The file wasn't a valid jpg file
325                      lblOutput.Text = "The file wasn't a valid jpg file.";
326                      System.IO.File.Delete(Server.MapPath(sSavePath + sFilename));
327                  }
328              }
329          }
330  
331          public bool ThumbnailCallback()
332          {
333              return false;
334          }
335          protected void btnUpload_Click1(object sender, EventArgs e)
336          {
337  
338          }
339          protected void txtFName_TextChanged(object sender, EventArgs e)
340          {
341  
342          }
343          protected void btnUpload_Click2(object sender, EventArgs e)
344          {
345  
346          }
347  }
348  }
349  

97                   if (System.IO.File.Exists(Server.MapPath(sSavePath + sFilename)))
98                   {
99                       Response.Write("&lt;script type=\"text/javascript\"&gt;var result = confirm('Image already existed. Click OK to overwrite. Click NO for new filename.')</script>");
100                    
101                  }

is this correct? how do i write if (result == yes) ... etc?

Here is a sample showing how to do that.

aspx file:

<form id="Form1" method="post" runat="server">
 Select a file to upload:
 <input type="file" id="fileUploadControl" runat="Server">
 <input type="submit" id="uploadButton" runat="Server" value="Upload..." OnServerClick="uploadButton_Click">
 <br><br>
 <asp:label id="messageArea" runat="server"></asp:label>
</form>

aspx.cs file:

protected string SavedFileName
{
 get
 {
  object viewState = this.ViewState["SavedFileName"];
  
  return (viewState == null) ? string.Empty : (string)viewState;
 }
 set
 {
  this.ViewState["SavedFileName"] = value;
 }
}

protected void uploadButton_Click(Object sender, EventArgs e)
{
 this.fileUploadControl.PostedFile.FileName

 string uploadFilePath = this.fileUploadControl.PostedFile.FileName;
 string [] filePathArray = uploadFilePath.Split('\\');

 if ( filePathArray.Length <= 0 )
  return;

 string fileName = filePathArray[filePathArray.Length-1];
 string filePath = this.Server.MapPath("Uploads") + "\\" + fileName;
 string tempFilePath = this.Server.MapPath("Temp") + "\\" + fileName;
 bool shouldQueryUser = false;

 try
 {
  if ( System.IO.File.Exists(filePath) )
  {
   shouldQueryUser = true;
   filePath = tempFilePath;
  }

  if ( System.IO.File.Exists(filePath) )   
   System.IO.File.Delete(filePath);

  this.fileUploadControl.PostedFile.SaveAs(filePath);
  this.messageArea.Text = "Successful Upload!<br>";
 }
 catch(Exception ex)
 {
  this.messageArea.Text = "Error saving file: " + fileUploadControl.Value + "<br>" + ex.ToString() + "<br>";
 }

 if ( shouldQueryUser )
 {
  this.SavedFileName = fileName;
  System.Text.StringBuilder javaScript = new System.Text.StringBuilder();
  
  javaScript.Append("\n<script type=text/javascript>\n");
  javaScript.Append("<!--\n");

  javaScript.Append("var overwriteVerification = window.confirm('Do you wish to overwrite?');\n");
  javaScript.Append("__doPostBack('FileOverwritePostBack', overwriteVerification);\n");

  javaScript.Append("// -->\n");
  javaScript.Append("</script>\n");
  
  RegisterStartupScript(scriptKey, javaScript.ToString());
 }
}

protected void deleteFile()
{
 this.messageArea.Text = string.Empty;

 string fileName = this.SavedFileName;
 string tempFilePath = this.Server.MapPath("Temp") + "\\" + fileName;
 this.SavedFileName = string.Empty;

 try
 {
  if ( System.IO.File.Exists(tempFilePath) )   
   System.IO.File.Delete(tempFilePath);
 }
 catch(Exception ex)
 {
  this.messageArea.Text = "Error deleting file: " + fileName + "<br>" + ex.ToString() + "<br>";
 }
}

protected void moveFile()
{
 this.messageArea.Text = string.Empty;

 string fileName = this.SavedFileName;
 string filePath = this.Server.MapPath("Uploads") + "\\" + fileName;
 string tempFilePath = this.Server.MapPath("Temp") + "\\" + fileName;
 this.SavedFileName = string.Empty;

 try
 {
  if ( System.IO.File.Exists(filePath) )   
   System.IO.File.Delete(filePath);

  // Move the file.
  System.IO.File.Move(tempFilePath, filePath);
 }
 catch(Exception ex)
 {
  this.messageArea.Text = "Error moving file: " + fileName + "<br>" + ex.ToString() + "<br>";
 }
}

private void Page_Load(object sender, System.EventArgs e)
{
 // Insure that the __doPostBack() JavaScript is added to the page...
 this.GetPostBackEventReference(this, string.Empty);

 if ( this.IsPostBack )
 {
  string eventTarget = (this.Request["__EVENTTARGET"] == null) ? string.Empty : this.Request["__EVENTTARGET"];
  string eventArgument = (this.Request["__EVENTARGUMENT"] == null) ? string.Empty : this.Request["__EVENTARGUMENT"];

  if ( eventTarget = "FileOverwritePostBack" )
  {
   if ( eventArgument == "true" )
    this.moveFile();
   else
    this.deleteFile();
  }
 }
}

Note that RegisterOnSubmitStatement, RegisterStartupScript, RegisterClientScriptBlock, etc have changed since version 1.1 and you will get a compiler warning with the above.
See http://msdn2.microsoft.com/en-us/library/system.web.ui.clientscriptmanager.aspx for more info.

NC...