Default value in WPF Binding

问题

I've bound the Height and Width of my window. Now, the window is so tiny in Visual Studio I can't work on it anymore. Setting default values to Height and Width would solve my problem. Is it possible in Binding?

<Window
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    x:Class="Sth.MainWindow"
    x:Name="Window"
    Width="{Binding Path=WidthOfImage, Mode=TwoWay}"
    Height="{Binding Path=HeightOfImage, Mode=TwoWay}"
    >
    ...
</Window>

Can we set default values in WPF Binding? How?

回答1:

See FallbackValue:

<Window
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    x:Class="Sth.MainWindow"
    x:Name="Window"
    Width="{Binding Path=WidthOfImage, Mode=TwoWay, FallbackValue=200}"
    Height="{Binding Path=HeightOfImage, Mode=TwoWay, FallbackValue=150}"
    >
    ...
</Window>

You might also be able to use MinWidth or MinHeight to address your small window issue.

来源：https://stackoverflow.com/questions/2238905/default-value-in-wpf-binding