How to get ValueMember value from ComboBox C# Winf

问题:

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();
        }
    }

回答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;

回答2:

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

回答3:

This worked for me:

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