Difference between ' (single quote) and “ (double quote) in ASP.NET 4

Question

I want to call MyMethod in code-behind from server control in aspx page like below.

MyPage.aspx

<asp:Label ID="MyLabel" runat="server" Text='<%# MyMethod(Eval("MyColumn")) %>'>

MyPage.aspx.cs

protected void MyMethod(object obj) { ... }

If I use " instead ' in aspx page then it will give me a compilation error The server tag is not well formed. as below.

<asp:Label ID="MyLabel" runat="server" Text='<%# MyMethod(Eval("MyColumn")) %>'> // This line work
<asp:Label ID="MyLabel" runat="server" Text="<%# MyMethod(Eval("MyColumn")) %>"> // This line error

I want to know why I need to use single-quote, is it a rule? How can I use double-quote in my situation?

Answer 1

I want to know why I need to use single-quote, is it a rule? How can I use double-quote in my situation?

The use of Single quote over Double quote is just to make it clear where the string is ending. You cannot use Text="MyMethod("123")" because the Text start with the M and may end with the ( or the 3 or the last ). By using single and double quote the compiler know when the string end.

Text="MyMethod('123')"

Text='MyMethod("123")'

Your example is about binding but let say that you would like to have a double quote while using a double quote for a non-binding situation. You could have use the HTML entity "

Text="This is my string with  " inside "" //This will produce : This is my string with "inside"