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c#wpfxamlbindingstring-formatting

Is there a way to make XAML / C# StringFormat show whole dollars for larger amounts but cents for smaller amounts?

In XAML, it is easy enough to use StringFormat='$#,0;$-#,0;Nil' to make a bound integer variable display as a nicely formatted dollar amount. e.g., 1024 would come out as '$1,024'.

I have a need to deal with numbers ranging from a few cents up to a few hundred dollars - so 0.45 should display as '$0.45', but anything greater than some threshold (1? 9.99?) should display as a whole dollar amount. E.g. 12.73 should display as '$13'.

Before I go ahead and roll some moderately messy and specific code, does anyone have a nice clever way to do this? Ideally, it would all be in the StringFormat :)

Solution

  • I can't see how all this logic can be put in the StringFormat.

    I think the cleanest way is an IValueConverter implementation. You can use a converter parameter to set the threshold, so that the converter can be reused and does not have a hard-coded value.

    Unless you are using two-way binding, and if you are implementing MVVM, it is probably preferable to have a string variable in the view-model that returns the display value based on the integer value.