I'm using a code-behind function (called TestFx) in my binding expression. I'm passing a string and the function accepts a string but I still get a runtime error saying invalid args.
But if I change the method to accept an object and inspect the value, "it's a string!"
Can someone please explain?
-rod
ProductDescription:
<asp:Label ID="ProductDescriptionLabel" runat="server"
Text='<%# TestFx(Eval("ProductDescription")) %>' />
<br />
Another option is to handle repeater control ItemDataBound event. It's more suitable if ItemTemplate elements require complex decoration
The return type of Eval is object. As you've noticed, you can either change the signature of your method to accept an object, or you can typecast the result of Eval("ProductDescription") to a string:
<asp:Label ID="ProductDescriptionLabel" runat="server"
Text='<%# TestFx(Eval("ProductDescription").ToString()) %>' />
Related
I have looked for other solutions here on StackOverflow but i cant seem to figure it out.
I have this linkbutton in a datagrid:
<asp:LinkButton
ID="lnkname" runat="server"
Text='<%#Eval("Titel") %>'
PostBackUrl='<%#"Details.aspx?ID="+Eval("ID").toString()%>'
CausesValidation="false">
</asp:LinkButton>
and this is the paramater:
<asp:ControlParameter ControlID="txtTitel" DefaultValue="*" Name="Titel"
PropertyName="Text" Type="String" ConvertEmptyStringToNull="False" />
I want to take the ID value to the next page : details.aspx but i get the following error:
Input string was not in a correct format.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.FormatException: Input string was not in a correct format.
I know it has something to do with ID being a INT but I cant figure out how to fix it.
NOTE: I do it in VB.NET
There is problem in casting it to string
+Eval("ID").toString()
use this
PostBackUrl='<%# "Details.aspx?ID="+Eval("ID").ToString() %>'
The .toString() should be ToString()
Edit 1
Or you can use
Try using a HyperLinkField
http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.hyperlinkfield.aspx
<asp:HyperLinkField
HeaderText="Client IP"
DataNavigateUrlFields="IP"
DataNavigateUrlFormatString="Details.aspx?id={0}"
DataTextField="ID"
DataTextFormatString="{0}"/>
If you need to pass multiple parameters then you can use & between them For example
PostBackUrl='<%# "Details.aspx?ID="+Eval("ID")+"&x=50" %>'
Important
Whenever you are concatenating(joining) a variable of any type like Eval("ID") value to a string like "Details.aspx?ID=", You do not need to write ToString() for casting becasue concatenation does this casting implicitly (automatically). I am sure about this behaviour for C# and VB.NET
So you could write simply
PostBackUrl='<%# "Details.aspx?ID="+Eval("ID") %>'
Suppose I have this label in my aspx page:
<asp:Label ID="savings" runat="server" Text='<%# Eval("savings")%>' />
Is there a way to format the text of a label as a currency-formatted string? I'm looking for something like this:
<asp:Label ID="savings" runat="server" Text='<%# Eval("savings").ToString("C")%>' />
When I run this I get the:
No overload for method 'ToString' takes 1 arguments
compilation error.
I know I can easily do this in my code-behind but I want to know if it's possible from the .aspx document.
Try this code:
<asp:Label ID="savings" runat="server" Text='<%# string.Format("{0:C}", Eval("savings"))%>' />
Try this code if you are dealing with string
<asp:Label ID="savings" runat="server" Text='<%# String.Format("{0:c}", Convert.ToDecimal(Eval("savings")))%>' />
The ToString(string) method only operates on numerical types, but Eval(string) returns object.
Cast the result to the correct type before calling the extension method on it, like this:
<%# ((decimal)Eval("savings")).ToString("C") %>
Late.. but useful
Anyone looking for Indian Currency Format or any other Currency use the CultureInfo class.
example:
(YourData).ToString("C2",CultureInfo.CreateSpecificCulture("in-IN"));
i would recommend that you convert the data you are trying to format to decimal in order to skip any overheads, also check this page for more culture combinations and more about formatting.
I made a function to truncate a string in the code behind file. But how do i use it in the aspx file?
This is the textbox:
<asp:TemplateField HeaderText="page" HeaderStyle-Wrap="true">
<ItemTemplate>
<a href='<%# makepageURL( Eval("page") )%> '>
<%# Eval("page")%>
</a>
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox ID="txtpage" TextMode="SingleLine" Rows="1" Width="100%" runat="server" Text='<% #Bind("page") %>' />
</EditItemTemplate>
</asp:TemplateField>
And this is my function:
Public Function TrimString(ByVal Value As String, ByVal Length As Integer) As String
If Value.Length > 20 Then
Return Value.Substring(Value.Length - (20 - 3)) + "..."
End If
Return Value
End Function
It's not an issue of how to use it, but actually when to use it?
If you had a regular span, you could do this:
<span><%: TrimString("somestring") %></span>
But this is a TextBox your dealing with (user input).
When should it truncate?
On Form Submit? (that would make sense).
As they type (well then you'd need to use JavaScript).
By the looks of your code snipper, your using a FormView.
So i wouldn't be calling it from the ASPX (which the equivalent of executing code during Page Render), i would be calling it during the Edit/Submit event, server-side event handler.
In other words, truncate the value the user put in, after they have submitted the form and before you persist to the database.
I have an application with ajax star rating but when i am assigning value to CurrentRating from datatable then it showing error of "Specified cast is not valid".
I am using this code.
<asp:TemplateField HeaderText="Rating" SortExpression="CustomerRating">
<ItemTemplate>
<asp:Label ID="Label2" runat="server" Text='<%#DataBinder.Eval(Container.DataItem, "CustomerRating")%>'></asp:Label></a>
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<cc1:Rating ID="Rating1" runat="server" CurrentRating='<%# Bind("CustomerRating") %>'
StarCssClass="ratingStar"
WaitingStarCssClass="savedRatingStar"
FilledStarCssClass="filledRatingStar"
EmptyStarCssClass="emptyRatingStar"
>
</cc1:Rating>
</ContentTemplate>
</asp:UpdatePanel>
</ItemTemplate>
</asp:TemplateField>
Then its showing error CurrentRating='<%# Bind("CustomerRating") %>'.
I am taking refrence from these sites.
asp.net forum
Code Project
Same thing working on Code project.
The problem is most likely that the CustomerRating property of your data item is not of the correct data type. Rating expects an int. The Databinder does use reflection and attempts to automatically handle type conversions, but it has limits.
Unfortunatly there isn't enough information in your qustion to know what the actual runtime type of CustomerRating is, so I can't say why it can't be cast. My advise would be to explicitly cast or convert the property like so:
CurrentRating='<%# (string)Bind("CustomerRating") %>'
CurrentRating='<%# Bind("CustomerRating").ToString() %>'
CurrentRating='<%# (int)Bind("CustomerRating") %>'
If you can't convert it simply, or just need to get a debugger on it so you can figure out what the type is you can call out to a custom method in your code-behind instead (and you can attach a debugger there to so you can see the runtime type of the item:
CurrentRating='<%# MyCustomMethod(Eval("CustomerRating")) %>'
in code behind:
public string MyCustomMethod(object customerRating)
{
string rValue = ... //do whatever you need to do to customerRating to get a string out of it
// good place to set a breakpoint you you can examine what type customerRating actually is so you can figure out how best to convert it to something databinding can use
return rValue;
}
I'd like to set a button's enabled state to be the negation of a value.
So given this code:
<asp:CheckBox ID="DefaultChecked"
Checked='<%# Bind("IsDefaultMessage") %>'
Enabled="false"
runat="server" />
<asp:LinkButton ID="MakeDefaultButton"
runat="server"
CommandName="MakeDefault'
CommandArgument='<%# Bind("ResidentialInfoID") %>'
Text="Make Default" />
How can I make the LinkButton Enabled attribute false if IsDefaultMessage == true?
Use Eval instead of Bind. Bind is for two-way binding, i.e. for cases where you need to be able to save the data back to your data source.
When you use Bind, the compiled page will actually have generated code that uses Eval to set the value, plus some code to read out the value for saving. Because Bind is replaced with generated code, you can't use any extra logic with Bind.
<asp:CheckBox ID="DefaultChecked" Checked='<%# !(bool)Eval("IsDefaultMessage") %>' Enabled="false" runat="server" />
<asp:LinkButton ID="MakeDefaultButton" runat="server" CommandName="MakeDefault' CommandArgument='<%#Bind("ResidentialInfoID") %>' Text="Make Default"/>
If you can use Eval, it is just a method of the Control class. It's only special in that it needs to be in the context of a data bound block <%# ... %>. Other than that, you can basically treat the block like a regular <%= %> expression block:
<%# !(bool)Eval("IsDefaultMessage") %>
If you want to still Bind it (Eval isn't round-trip), than you'll need to negate it back and forth during databinding. You may not need to do this though, if you can just re-word the control. For example, if a check box, instead of labelling it "Is Not Default Message" to the user and negating it back and forth, than lable it "Is Default Message". Contrived example, but you get the idea.
In case someone is looking for an option with VB.Net
<asp:CheckBox ID="DefaultChecked" Checked='<%# NOT (Eval("IsDefaultMessage")) %>' Enabled="false" runat="server" />
I've never used Bind but my understanding is that it is similar to Databinder.Eval. Either way, both methods return objects so you need to cast it to a boolean before evaluating it.
<%# !Convert.ToBoolean(Bind("IsDefaultMessage") %>
Edit: Looks like this can't be done and using a SqlDataSource on the page would solve the problem. http://forums.asp.net/t/1009497.aspx.
As I recall (It's been a while), there's no particular magic in <%#Bind(. It's just #Bind( inside <%....%>. Which means you'd want:
<% ! #Bind("IsDefaultMessage") %>'
The code
Checked='<%# Eval("IsDefaultMessage").ToString().Length() > 4 %>'
will return true if IsDefaultMessage is false
Since "False".Length = 5 and "True".Length = 4