here's the deal I got a datagridviewer which is called gridview1 and a fileupload1 when i upload a file it updates the gridview1 and table in database with the file name and path and stores the said file in folder "Mag"... but now what i want to do is the reverse i got how to use the gridview to delete the table entry but deleting the file from folder "Mag" is not working have used the following code in C# or codebehind
protected void GridView1_Del(object sender, EventArgs e)
{
string DeleteThis = GridView1.SelectedRow.Cells[0].Text;
string[] Files = Directory.GetFiles(@"i:/Website/WebSite3/Mag/");
foreach (string file in Files)
{
if (file.ToUpper().Contains(DeleteThis.ToUpper()))
{
File.Delete(file);
}
}
}
it gives me error
"Object reference not set to an instance of an object."
pls tell me what im doing wrong am new and don't have to in depth understanding of the platform so any and all help will be appreciated thanks in advance Mark
Here is the answer i found Thanks Tammy and everyone else for all the answers
Ok here the deal target function delete file details from gridview and database table and file from project folder where the file is stored
in script section of gridview you would want to include
OnRowDeleting="FuntionName"
Not
OnSelectedIndexChanged = "FuntionName"
or
OnRowDeleted="FuntionName"
then in C# code(codebehind)
protected void FuntionName(object sender, GridViewDeleteEventArgs e)
{
// storing value from cell
TableCell cell = GridView1.Rows[e.RowIndex].Cells[0];
// full path required
string fileName = ("i:/Website/WebSite3/Mag/" + cell.Text);
if(fileName != null || fileName != string.Empty)
{
if((System.IO.File.Exists(fileName)))
{
System.IO.File.Delete(fileName);
}
}
}
And just for added reference for those who want to learn
OnRowDeleting="FuntionName" is for just before deleting a row you can cancel deleting or run functions on the data like i did
OnRowDeleted="FuntionName" it directly deletes
This is how I delete files
if ((System.IO.File.Exists(fileName)))
{
System.IO.File.Delete(fileName);
}
Also make sure that the file name you are passing in your delete, is the accurate path
EDIT
You could use the following event instead as well or just use the code in this snippet and use in your method
void GridView1_SelectedIndexChanged(Object sender, EventArgs e)
{
// Get the currently selected row using the SelectedRow property.
GridViewRow row = CustomersGridView.SelectedRow;
//Debug this line and see what value is returned if it contains the full path.
//If it does not contain the full path then add the path to the string.
string fileName = row.Cells[0].Text
if(fileName != null || fileName != string.empty)
{
if((System.IO.File.Exists(fileName))
System.IO.File.Delete(fileName);
}
}
In my project i am using ajax and i create a web method in my code behind like this
in front
$("#attachedfiles a").live("click", function () {
var row = $(this).closest("tr");
var fileName = $("td", row).eq(0).html();
$.ajax({
type: "POST",
url: "SendEmail.aspx/RemoveFile",
data: '{fileName: "' + fileName + '" }',
contentType: "application/json; charset=utf-8",
dataType: "json",
success: function () { },
failure: function (response) {
alert(response.d);
}
});
row.remove();
});
in code behind
[WebMethod]
public static void RemoveFile(string fileName)
{
List<HttpPostedFile> files = (List<HttpPostedFile>)HttpContext.Current.Session["Files"];
files.RemoveAll(f => f.FileName.ToLower().EndsWith(fileName.ToLower()));
if (System.IO.File.Exists(HttpContext.Current.Server.MapPath("~/Employee/uploads/" + fileName)))
{
System.IO.File.Delete(HttpContext.Current.Server.MapPath("~/Employee/uploads/" + fileName));
}
}
i think this will help you.
string sourceDir = @"c:\current";
string backupDir = @"c:\archives\2008";
try
{
string[] picList = Directory.GetFiles(sourceDir, "*.jpg");
string[] txtList = Directory.GetFiles(sourceDir, "*.txt");
// Copy picture files.
foreach (string f in picList)
{
// Remove path from the file name.
string fName = f.Substring(sourceDir.Length + 1);
// Use the Path.Combine method to safely append the file name to the path.
// Will overwrite if the destination file already exists.
File.Copy(Path.Combine(sourceDir, fName), Path.Combine(backupDir, fName), true);
}
// Copy text files.
foreach (string f in txtList)
{
// Remove path from the file name.
string fName = f.Substring(sourceDir.Length + 1);
try
{
// Will not overwrite if the destination file already exists.
File.Copy(Path.Combine(sourceDir, fName), Path.Combine(backupDir, fName));
}
// Catch exception if the file was already copied.
catch (IOException copyError)
{
Console.WriteLine(copyError.Message);
}
}
// Delete source files that were copied.
foreach (string f in txtList)
{
File.Delete(f);
}
foreach (string f in picList)
{
File.Delete(f);
}
}
catch (DirectoryNotFoundException dirNotFound)
{
Console.WriteLine(dirNotFound.Message);
}
Check the GridView1.SelectedRow is not null:
if (GridView1.SelectedRow == null) return;
string DeleteThis = GridView1.SelectedRow.Cells[0].Text;
Delete any or specific file type(for example ".bak") from a path. See demo code below -
class Program
{
static void Main(string[] args)
{
// Specify the starting folder on the command line, or in
TraverseTree(ConfigurationManager.AppSettings["folderPath"]);
// Specify the starting folder on the command line, or in
// Visual Studio in the Project > Properties > Debug pane.
//TraverseTree(args[0]);
Console.WriteLine("Press any key");
Console.ReadKey();
}
public static void TraverseTree(string root)
{
if (string.IsNullOrWhiteSpace(root))
return;
// Data structure to hold names of subfolders to be
// examined for files.
Stack<string> dirs = new Stack<string>(20);
if (!System.IO.Directory.Exists(root))
{
return;
}
dirs.Push(root);
while (dirs.Count > 0)
{
string currentDir = dirs.Pop();
string[] subDirs;
try
{
subDirs = System.IO.Directory.GetDirectories(currentDir);
}
// An UnauthorizedAccessException exception will be thrown if we do not have
// discovery permission on a folder or file. It may or may not be acceptable
// to ignore the exception and continue enumerating the remaining files and
// folders. It is also possible (but unlikely) that a DirectoryNotFound exception
// will be raised. This will happen if currentDir has been deleted by
// another application or thread after our call to Directory.Exists. The
// choice of which exceptions to catch depends entirely on the specific task
// you are intending to perform and also on how much you know with certainty
// about the systems on which this code will run.
catch (UnauthorizedAccessException e)
{
Console.WriteLine(e.Message);
continue;
}
catch (System.IO.DirectoryNotFoundException e)
{
Console.WriteLine(e.Message);
continue;
}
IEnumerable<FileInfo> files = null;
try
{
//get only .bak file
var directory = new DirectoryInfo(currentDir);
DateTime date = DateTime.Now.AddDays(-15);
files = directory.GetFiles("*.bak").Where(file => file.CreationTime <= date);
}
catch (UnauthorizedAccessException e)
{
Console.WriteLine(e.Message);
continue;
}
catch (System.IO.DirectoryNotFoundException e)
{
Console.WriteLine(e.Message);
continue;
}
// Perform the required action on each file here.
// Modify this block to perform your required task.
foreach (FileInfo file in files)
{
try
{
// Perform whatever action is required in your scenario.
file.Delete();
Console.WriteLine("{0}: {1}, {2} was successfully deleted.", file.Name, file.Length, file.CreationTime);
}
catch (System.IO.FileNotFoundException e)
{
// If file was deleted by a separate application
// or thread since the call to TraverseTree()
// then just continue.
Console.WriteLine(e.Message);
continue;
}
}
// Push the subdirectories onto the stack for traversal.
// This could also be done before handing the files.
foreach (string str in subDirs)
dirs.Push(str);
}
}
}
for more reference - https://msdn.microsoft.com/en-us/library/bb513869.aspx
Source: Stackoverflow.com