My razor code icludes this telerik dropdown list:
<TelerikDropDownList Data="@BkAccounts" TextField="@(nameof(BkAccounts.DisplayField))" ValueField="@(nameof(BkAccounts.BIC))" Value=1 ></TelerikDropDownList>
It points to this class:
public class BkAccounts
{
public int Id { get; set; }
public string Iban { get; set; }
public string BIC{ get; set; }
public string DisplayField{ get { return this.Iban + " - " + this.BIC; } }
}
If I write it this way, the dropdown list does not populate correctly.
If I change it this way:
<TelerikDropDownList Data="@BkAccounts" TextField="@(nameof(BkAccounts.DisplayField))" ValueField="@(nameof(BkAccounts.Id))" Value=1 ></TelerikDropDownList>
It works fine.
Actually, I want to remove the Id field from this BkAccounts class but I am not able to have the DDL to populatecorrectly. What did I miss? According to Telerik doc, TextField can accept a string field so it should not be a format problem...
Edit: the difference between the 2 snippets stands here: ValueField="@(nameof(BkAccounts.BIC) ---> does NOT populate ValueField="@(nameof(BkAccounts.Id) ---> populates like a charm
2 Answers
I got the answer from Telerik forum:
I needed to add into my TelerikDropDownList code: @bind-Value=@SelectedBankAccount and declare it as a string property into theviewmodel
I start to strongly suspect that the issue is on Telerik side. Here is their sample TelerikDropDownList code from
@page "/dropdownlist/overview"
@page "/dropdownlist/index"
@using TelerikBlazorDemos.Shared
<div class="example-box-wrapper">
<div class="example">
<div class="mb-4">T-Shirt size:</div>
<TelerikDropDownList Data="@Data"
@bind-Value=@SelectedSizeMetric
PopupHeight=""
DefaultText="Select your T-shirt size"
ValueField="SizeMetric" TextField="SizeText">
</TelerikDropDownList>
</div>
<div class="ml-4">
Selected Size Number: <strong>@SelectedSizeMetric</strong>
</div>
</div>
@code {
public IEnumerable<Size> Data { get; set; }
public bool AllowCustom { get; set; } = true;
public int? SelectedSizeMetric { get; set; }
public string SelectedSize { get; set; }
public class Size
{
public string SizeText { get; set; }
public int? SizeMetric { get; set; }
}
protected override void OnInitialized()
{
List<Size> sizes = new List<Size>();
sizes.Add(new Size()
{
SizeText = "X-Small",
SizeMetric = 3
});
sizes.Add(new Size()
{
SizeText = "Small",
SizeMetric = 6
});
sizes.Add(new Size()
{
SizeText = "Medium",
SizeMetric = 8
});
sizes.Add(new Size()
{
SizeText = "Large",
SizeMetric = 10
});
sizes.Add(new Size()
{
SizeText = "X-Large",
SizeMetric = 12
});
Data = sizes.AsQueryable();
base.OnInitialized();
}
}
It works fine as it is. But if I change:
ValueField="SizeMetric" //int type
for:
ValueField="SizeText" //string type
it nolonger works... I get: System.InvalidCastException : 'Unable to cast object of type 'System.String' to type 'System.Nullable`1[System.Int32]'.'
