Using .NET string formatting, how do I format a string to display blank (empty string) for zero (0)?

问题

I am using a DataBinder.Eval expression in an ASP.NET Datagrid, but I think this question applies to String formatting in .NET in general. The customer has requested that if the value of a string is 0, it should not be displayed. I have the following hack to accomplish this:

<%# IIf(DataBinder.Eval(Container.DataItem, "MSDWhole").Trim = "0", "", 
    DataBinder.Eval(Container.DataItem, "MSDWhole", "{0:N0}"))  %>

I would like to change the {0:N0} formatting expression so that I can eliminate the IIf statement, but can't find anything that works.

回答1:

You need to use the section separator, like this:

<%# DataBinder.Eval(Container.DataItem, "MSDWhole", "{0:N0;; }").Trim() %>

Note that only the negative section can be empty, so I need to put a space in the 0 section. (Read the documentation)

回答2:

Given the accepted answer:

<%# DataBinder.Eval(Container.DataItem, "MSDWhole", "{0:N0;; }").Trim() %>

The a space is placed in the the 3rd position, however placing a # in the third position will eliminate the need to call Trim().

<%# DataBinder.Eval(Container.DataItem, "MSDWhole", "{0:N0;;#}") %>

回答3:

Use a custom method.

public static string MyFormat(double value) {       
    return value == 0 ? "" : value.ToString("0");
}

<%# MyFormat(Convert.ToDouble(Eval("MSDWhole"))) %>

回答4:

Try to call a function while binding like this

<%# MyFunction( DataBinder.Eval(Container.DataItem, "MSDWhole") ) %>

and inside the function make the formatting you want

来源：https://stackoverflow.com/questions/2282573/using-net-string-formatting-how-do-i-format-a-string-to-display-blank-empty-s