Member Avatar for ginger182

Hi I'm really new to C#, more familiar with .ne but haven't code much in a while.

I am not sure how to populate a table with data after clicking a search button.. know how to do this in .net but eve after looking at examples I'm not sure how to do this in C#

this is what I have in .net but i need to find a way to do it in C# since the whole project will be in C#.
is there another way to use "Dim" ?

protected Sub seachMarks_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles searchMarks.Click
 
  Dim systemmgr As New SchoolSystem.Controller
        Dim myDS As DataSet
        Try
            myDS = systemmgr.GetMarkSubmissionList(courseid.Text, semester.Text)
            If myDS.Tables(0).Rows.Count = 0 Then
                FormMessage.Text = "No students in this course/semester."
            Else
                myDS.Tables(0).DefaultView.Sort = "Name ASC"
                MarkList.DataSource = myDS.Tables(0)
                MarkList.DataBind()
            End If
        Catch ex As Exception
            FormMessage.Text = ex.Message
        End Try
    End Sub
  • 4 Contributors
  • 4 Replies
  • 107 Views
  • 9 Hours Discussion Span
  • Latest Post Latest Post by dnanetwork

Dani AI

Generated

The general approach shown in the thread is fine: call your business/controller layer with the search parameters, examine the result, and then bind whatever tabular data you got back to the grid. 's C# conversion is helpful for syntax, but it contains two common runtime pitfalls worth calling out: the controller variable is declared but not instantiated (this will throw a NullReferenceException when you call its method), and the code assumes the returned dataset always contains a table. Always instantiate your controller and defensively verify the returned object is non-null and that Tables.Count > 0 before accessing Tables[0].

Practical hardening steps:

  • Validate and sanitize courseid and semester before sending them to the data layer.
  • Return a single DataTable or a typed list from your data layer if the query always returns one table — it simplifies checks and binding.
  • Prefer parameterized queries or stored procedures in the data layer to avoid SQL injection.
  • If you keep ADO.NET objects, check for null, check Tables.Count, and examine Rows.Count before binding.
  • Make sure the ASPX grid has columns defined or AutoGenerateColumns set, and that the search button is wired to the correct event (and included as a trigger if using an UpdatePanel).

If you want less plumbing, consider declarative data controls (SqlDataSource/ObjectDataSource) or using LINQ/Entity Framework to return IEnumerable<T>; they simplify binding and sorting. For reference on the ADO.NET model and ASP.NET data binding patterns see Microsoft’s docs on DataSet/DataView and Web Forms data binding:

Quick checklist for debugging: set breakpoints, inspect the returned object, confirm the controller is constructed, confirm the event is firing, and watch for exceptions in the output window.

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Member Avatar for lighthead

A few things about your post
1) Use Code tags like this , if you didn't already know.
2) .NET is not a language, the language you are using is VB.
3) If you already know to program on .NET with VB its not too difficult to learn to do it in C#. Here is a starter.

Member Avatar for ema005

If you know VB.net, then C# become simpler for you to learn. Some of the things you are used to doing in VB using the .Net frame work are still available in c# only the syntaxes are different. I have converted your code to C# for you so that you can compare and learn from it.

protected void seachMarks_Click(object sender , EventArgs e)
	   {

	          SchoolSystem.Controller systemmgr;
	   	 	
	   	DataSet myDS;
	   	
	   	try
	   	{
	   	myDS = systemmgr.GetMarkSubmissionList(courseid.Text, semester.Text);
	   		if(myDS.Tables[0].Rows.Count == 0)
	   		{
	   			FormMessage.Text = "No students in this course/semester.";
	   		}
	   		else
	   		{
	   			myDS.Tables[0].DefaultView.Sort = "Name ASC";
	   			MarkList.DataSource = myDS.Tables(0);
	   		    MarkList.DataBind();
	   		}
	   		
	   		 
	    }

    	     catch (Exception ex)
	   	{
	   		FormMessage.Text = ex.Message;
	   	}
	   }
    }
Member Avatar for ema005

If you know VB.net, then C# become simpler for you to learn. Some of the things you are used to doing in VB using the .Net frame work are still available in c# only the syntaxes are different. I have converted your code to C# for you so that you can compare and learn from it.

protected void seachMarks_Click(object sender , EventArgs e)
	   {

	          SchoolSystem.Controller systemmgr;
	   	 	
	   	DataSet myDS;
	   	
	   	try
	   	{
	   	myDS = systemmgr.GetMarkSubmissionList(courseid.Text, semester.Text);
	   		if(myDS.Tables[0].Rows.Count == 0)
	   		{
	   			FormMessage.Text = "No students in this course/semester.";
	   		}
	   		else
	   		{
	   			myDS.Tables[0].DefaultView.Sort = "Name ASC";
	   			MarkList.DataSource = myDS.Tables(0);
	   		                MarkList.DataBind();
	   		}
	   		
	   		 
	     }

    	     catch (Exception ex)
	   	{
	   		FormMessage.Text = ex.Message;
	   	}
	   }
    }
Member Avatar for dnanetwork

you need to fire the select query.....when click search..at that time..

pass your search parameter and bind the datagrid...

i'm sure that will work...

hope it helps...

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