CODEWITHSUNDEEP
c#combobox
user2944173
user2944173

Reputation: 65

To get selected item in dynamic control -combobox

I have created a ComboBox dynamically, but I need to select the value from SelectedIndexChanged. I am getting the following error:

Object reference not set to an instance of an object

private ComboBox TimeIntervel;
int Stimer; 
public void set control()
{
    ComboBox TimeIntervelCmb = new ComboBox();
    TimeIntervelCmb.Location = new Point(50,70);
    TimeIntervelCmb.Name = "ComboBoxTime";
    TimeIntervelCmb.Size = new Size(80, 100);
    TimeIntervelCmb.Items.Add("500");
    TimeIntervelCmb.Items.Add("1000");
    TimeIntervelCmb.Items.Add("2000");
    TimeIntervelCmb.Items.Add("3000");
    TimeIntervelCmb.Items.Add("4000");
    TimeIntervelCmb.Items.Add("5000");
    TimeIntervelCmb.Items.Add("6000");
    TimeIntervelCmb.SelectedIndexChanged += new EventHandler(TimeIntervel_SelectedIndexChanged);
    this.Controls.Add(TimeIntervelCmb);
}

private void TimeIntervel_SelectedIndexChanged(object sender, EventArgs e)
{
    try
    {
        if (TimeIntervel.SelectedItem  != null)// Object reference not set to an instance of an object.-Error
        {
            Stimer = int.Parse(TimeIntervel.SelectedItem.ToString());
        }
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message);
    }
}

Upvotes: 0

Views: 537

Answers (1)

Manfred Radlwimmer
Manfred Radlwimmer

Reputation: 13394

You create a ComboBox in a local variable named TimeIntervelCmb and never assign it to TimeIntervel, therefore TimeIntervel will always be null.

Add this line:

TimeIntervel = TimeIntervelCmb;

Or check the ComboBox instance that raises the event:

ComboBox combo = (ComboBox)sender;
if (combo .SelectedItem  != null)
// etc ...

Upvotes: 1

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