C# – Why changing SelectedItem in one Combo changes all other Combos

ccomboboxwinforms

I populated comboboxes in this way

foreach (Control c in this.Controls)
{
     if (c is ComboBox)
     {
         (c as ComboBox).DataSource = DataSet1.Tables[0];
         (c as ComboBox).DisplayMember = "Articles";
     }
}

But, problem is when I change SelectedItem in one Combo – it becomes changed in all other Combos?

Best Answer

Bind them each to a separate instance of the DataSet1.Table[0].

ie)

foreach (Control c in this.Controls)
{
    if (c is ComboBox)
    {
        DataTable dtTemp = DataSet1.Tables[0].Copy();
        (c as ComboBox).DataSource = dtTemp 
        (c as ComboBox).DisplayMember = "Articles";
    }
}

Related Solutions

C# – Cross-thread operation not valid: Control accessed from a thread other than the thread it was created on

As per Prerak K's update comment (since deleted):

I guess I have not presented the question properly.

Situation is this: I want to load data into a global variable based on the value of a control. I don't want to change the value of a control from the child thread. I'm not going to do it ever from a child thread.

So only accessing the value so that corresponding data can be fetched from the database.

The solution you want then should look like:

UserContrl1_LOadDataMethod()
{
    string name = "";
    if(textbox1.InvokeRequired)
    {
        textbox1.Invoke(new MethodInvoker(delegate { name = textbox1.text; }));
    }
    if(name == "MyName")
    {
        // do whatever
    }
}

Do your serious processing in the separate thread before you attempt to switch back to the control's thread. For example:

UserContrl1_LOadDataMethod()
{
    if(textbox1.text=="MyName") //<<======Now it wont give exception**
    {
        //Load data correspondin to "MyName"
        //Populate a globale variable List<string> which will be
        //bound to grid at some later stage
        if(InvokeRequired)
        {
            // after we've done all the processing, 
            this.Invoke(new MethodInvoker(delegate {
                // load the control with the appropriate data
            }));
            return;
        }
    }
}

C# – How to remedy “The breakpoint will not currently be hit. No symbols have been loaded for this document.” warning

Start debugging, as soon as you've arrived at a breakpoint or used Debug > Break All, use Debug > Windows > Modules. You'll see a list of all the assemblies that are loaded into the process. Locate the one you want to get debug info for. Right-click it and select Symbol Load Information. You'll get a dialog that lists all the directories where it looked for the .pdb file for the assembly. Verify that list against the actual .pdb location. Make sure it doesn't find an old one.

In normal projects, the assembly and its .pdb file should always have been copied by the IDE into the same folder as your .exe, i.e. the bin\Debug folder of your project. Make sure you remove one from the GAC if you've been playing with it.

Best Answer

Related Solutions

C# – Cross-thread operation not valid: Control accessed from a thread other than the thread it was created on

C# – How to remedy “The breakpoint will not currently be hit. No symbols have been loaded for this document.” warning

Related Topic