CODEWITHSUNDEEP
c#asp.netentitydatasource
BenW
BenW

Reputation: 1453

SelectedValue which is invalid because it does not exist in the list of items, how to handle this error

I am getting the below error when I try to bind data.

SelectedValue which is invalid because it does not exist in the list of items

<asp:DropDownList ID="DropDownList2" runat="server" 
     DataSourceID="JobCategoryEntityDataSource" DataTextField="ItemValue"
     DataValueField="ItemValue" SelectedValue='<%# Bind("JobCategory") %>' 
     Width="230px">
</asp:DropDownList>

I know the reason why I am getting this error. It is because it cant find the value in the selection. When JohCategory field from the transaction table can not find it in the list that is coming from JobCategoryEntityDataSource, it simply throws an error.

All I want to do is not bind the data if it can't find it in the dropdownlist and don't want to throw errors. How can I do this ?

Another option is if it can't find the matching value, just add "Please select" or something similar.

Can someone help please ?

Upvotes: 0

Views: 5075

Answers (2)

Hary
Hary

Reputation: 5818

You can select the value in DataBound event of the dropdown. You can check for the existence of value and then select it or you can implement try catch

<asp:DropDownList ID="DropDownList2" runat="server"
 DataSourceID="JobCategoryEntityDataSource" DataTextField="ItemValue"
 DataValueField="ItemValue" 
 Width="230px" OnDataBound="DropDownList2_DataBound">
</asp:DropDownList>

<asp:HiddenField ID="JobCategory" runat="server" value='<%# Bind("JobCategory") %>'></asp:HiddenField>

Code-Behind

protected void DropDownList2_DataBound(object sender, EventArgs e)  
{  
    try{
       HiddenField hf = (HiddenField)Form.FindControl("JobCategory");

       DropDownList2.SelectedValue = hf.Value;

    }Catch(Exception ex){

    }
}

Upvotes: 1

Echilon
Echilon

Reputation: 10254

You need to bind it in the code behind and either

  • Wrap the statement in a try/catch block
  • Check the item is there with FindByName first, then, optionally, add it if not.

Upvotes: 0

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