get Dropdown selected value SharePoint 2013

Question

I have a choice column in my SharePoint list called Njësia, I have created a dropdown in my solution and I want to retrieve selected value from dropdown list.

I have a label called Label1 and I want to represent the selected item in dropdown list.

I have the following code:

SPFieldChoice YearChoice = (SPFieldChoice)sampleList.Fields["Njësia"];
        for (int i = 0; i < YearChoice.Choices.Count; i++)
        {
            DropDownList4.Items.Add(YearChoice.Choices[i].ToString());
        }  
  string selectedvalyear = DropDownList4.SelectedValue;
  Label1.Text = selectedvalyear;

I also tried this line:

string selectedvalyear = DropDownList4.Text;

The result of Label1 is null or it displays only the first item in dropdown I have enable autopostback but nothing happens Please help me!

Answer 1

To get a SharePoint Choice Field value

SPFieldChoice myChoicesfield = (SPFieldChoice)list.Fields["FieldName"];
        for (int i = 0; i < myChoicesfield.Choices.Count; i++)
          {
            DropDownListName.Items.Add(myChoicesfield.Choices[i].ToString());
          }

To get a SharePoint Multiple Choice Field value

SPFieldMultiChoiceValue itemValue = 
new SPFieldMultiChoiceValue(item["FieldName"].ToString());
foreach (string choice in itemValue)
{
// value is in choice
}

Ref: Get and Set a SharePoint Multiple Choice Field Value in C#

Regarding your code

normally, the above code retrieves only one item or null because the selected value only gets one value if the dropdown has items or null if it's empty.

So try to get the count of dropdown list items to make sure that you have already retrieved the data properly using the above code before you assign the selected value to the label, in Selected Index Changed Event don't forget to surround your code with

If(!Page.IsPostBack)
{
Label.text = dropdownlist.Text;
}

P.S: The issue may not be tied to retrieving values but rather to the scenarios in your code.

Answer 2

From where DropDown1 came? In your code you are adding items in DropDownList4 and you are trying to access the value from DropDown1.

Your code should be like:

string selectedvalyear = Convert.ToString(DropDownList4.SelectedItem);
Label1.Text = selectedvalyear;

If you want to change the value of Lable1 from dropdown every time when you change item, then you must create a SelectedIndexChanged Event of DropDown and write above code in that event.

Solution-2:

You should write your code in :

If(!Page.IsPostBack)
{
SPFieldChoice YearChoice = (SPFieldChoice)sampleList.Fields["Njësia"];
        for (int i = 0; i < YearChoice.Choices.Count; i++)
        {
            DropDownList4.Items.Add(YearChoice.Choices[i].ToString());
        }  
  string selectedvalyear = DropDownList4.SelectedValue;
  Label1.Text = selectedvalyear;
}

Answer 3

Make sure you write dropdown change event. Keep autopostback property to true.

In dropdown change event of your dropdown write below code.

protected void DropDownList4_SelectedIndexChanged(object sender, EventArgs e)
        {
                Label1.Text = DropDownList4.SelectedItem.Text;
        }

This will show display value of selected choice

You can also use:

  Label1.Text = DropDownList4.SelectedItem.Value;

This will show value (not display value) of selected choice

Your HTML block should look like:

<asp:DropDownList ID="DropDownList4" runat="server" Height="22px" AutoPostBack="true" OnSelectedIndexChanged="DropDownList4_SelectedIndexChanged">