How to get ValueMember value from ComboBox C# Winforms?

Question

I'm having some trouble trying to get the ValueMember value I've set. I'm trying to use a combobox to select a windows forms report. I can get the Name but not RptValue. Here's my code:

        private class Data
    {
        public string Name { get; set; }
        public string RptValue { get; set; }
    }

    private void BaseForm_Load(object sender, EventArgs e)
    {
        this.rvDoctorReportViewer.RefreshReport();
        comboBox1.Items.Add(new Data { Name="Select", RptValue="Select"});
        comboBox1.Items.Add(new Data { Name = "All Food Values", RptValue = "AllFoodValues.rdlc" });
        comboBox1.Items.Add(new Data { Name = "All Readings", RptValue = "AllReadings.rdlc" });
        comboBox1.Items.Add(new Data { Name = "Avg Food Values by Date", RptValue = "AvgFoodValuesByDate.rdlc" });
        comboBox1.Items.Add(new Data { Name = "Avg Food Values by Meal", RptValue = "AvgFoodValuesByMeal.rdlc" });
        comboBox1.Items.Add(new Data { Name = "Avg Readings by Date", RptValue = "AvgReadingsByDate.rdlc" });
        comboBox1.Items.Add(new Data { Name = "Avg Readings by Time", RptValue = "AvgReadingsByTime.rdlc" });
        comboBox1.Items.Add(new Data { Name = "Avg Readings by Event", RptValue = "AvgReadingsByEvent.rdlc" });
        comboBox1.Items.Add(new Data { Name = "Blood Pressure Chart", RptValue = "BPChart.rdlc" });
        comboBox1.Items.Add(new Data { Name = "Blood Pressure Report", RptValue = "BPReport.rdlc" });
        comboBox1.Items.Add(new Data { Name = "Detail Food Values by Meal", RptValue = "DetailFoodValuesByMeal.rdlc" });
        comboBox1.Items.Add(new Data { Name = "Doctor Detail Report", RptValue = "DoctorDetailReport.rdlc" });
        comboBox1.Items.Add(new Data { Name = "Food Chart", RptValue = "FoodChart.rdlc" });
        comboBox1.Items.Add(new Data { Name = "Pumper Detail Report", RptValue = "PumperDetailReport.rdlc" });
        comboBox1.Items.Add(new Data { Name = "Reading Charts", RptValue = "ReadingCharts.rdlc" });
        comboBox1.Items.Add(new Data { Name = "Total Daily Food Intake", RptValue = "TotalIntakeDailyFood.rdlc" });
        comboBox1.DisplayMember = "Name"; // This works fine
        comboBox1.ValueMember = "RptValue"; // This is the problem. It renders as RptValue instead of the value
        comboBox1.SelectedIndex = 0;
    }

    private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
    {
        if (comboBox1.SelectedIndex > 0)
        {
            string strReport;
            strReport = "ReportViewer." + comboBox1.ValueMember.ToString();
            rvDoctorReportViewer.Reset();
            rvDoctorReportViewer.LocalReport.ReportEmbeddedResource = strReport;
            this.rvDoctorReportViewer.RefreshReport();
        }
    }

Quieten

Answer 1

You should use the DataSource property. Try this:

BindingList<Data> _comboItems = new BindingList<Data>(); 
_comboItems.Add(new Data { Name = "Select", RptValue = "Select" });
_comboItems.Add(new Data { Name = "All Food Values", RptValue = "AllFoodValues.rdlc" });
...
comboBox1.DataSource = _comboItems;
comboBox1.DisplayMember = "Name";
comboBox1.ValueMember = "RptValue";

And then access the selected value:

strReport = "ReportViewer." + comboBox1.SelectedValue;

Brocklin

Ok, now I'm getting a different error on the report itself. It says "An error occurred during local report processing. The report definition for "reportname" has not been specified. Object reference not set to an instance of an object." Any ideas? – Quieten

@Quieten Can't say anything for sure without seeing some code. :) I would guess it has something to do with ReportPath (but I'm not sure). I will recommend posting a new question about this specific issue. – Brocklin

Ok, here is the link to that question: #16025049 – Quieten

Answer 2

  String s;
  s=comboBox1.SelectedValue.toString()

Vernissage

Answer 3

This worked for me:

    combobox.valuemember="id"
    combobox.displaymember="name"
    combobox.datasource=dt

Infatuation