ValueConverters.NET 工具包简单演示代码

ValueConverters.NET.Demo.xaml

<Window x:Class="WpfTutorials.NuGetValueConverters.Views.MainWindow"
        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"
        xmlns:conv="clr-namespace:ValueConverters;assembly=ValueConverters"
        Title="登录"
        Width="800"
        Height="600"
        WindowStartupLocation="CenterScreen"
        mc:Ignorable="d">
    <Window.Resources>
        <conv:BoolToVisibilityConverter x:Key="AgreementToVisibilityConverter" IsInverted="True" />

        <conv:ValueConverterGroup x:Key="UserNameToVisibilityConverter">
            <conv:StringIsNotNullOrEmptyConverter />
            <conv:BoolInverter />
            <conv:BoolToVisibilityConverter />
        </conv:ValueConverterGroup>

        <conv:ValueConverterGroup x:Key="PasswordLengthToVisibilityConverter">
            <conv:IsInRangeConverter MinValue="8" MaxValue="999" />
            <conv:BoolInverter />
            <conv:BoolToVisibilityConverter />
        </conv:ValueConverterGroup>

        <conv:ValueConverterGroup x:Key="AgeToVisibilityConverter">
            <conv:StringToDecimalConverter />
            <conv:IsInRangeConverter MinValue="18" MaxValue="99" />
            <conv:BoolInverter />
            <conv:BoolToVisibilityConverter />
        </conv:ValueConverterGroup>
    </Window.Resources>
    <Grid>
        <Border Padding="10"
                HorizontalAlignment="Center"
                VerticalAlignment="Center"
                CornerRadius="5"
                BorderBrush="Gray"
                Background="White"
                TextElement.FontSize="18"
                BorderThickness="1">
            <Border.Effect>
                <DropShadowEffect />
            </Border.Effect>
            <Border.Resources>
                <Style TargetType="TextBox">
                    <Setter Property="Width" Value="150" />
                </Style>
                <Style TargetType="TextBlock">
                    <Setter Property="Width" Value="75" />
                    <Setter Property="VerticalAlignment" Value="Center" />
                </Style>
                <Style TargetType="CheckBox">
                    <Setter Property="VerticalContentAlignment" Value="Center" />
                </Style>
            </Border.Resources>
            <StackPanel>
                <StackPanel Orientation="Horizontal">
                    <TextBlock>用户名：</TextBlock>
                    <TextBox Name="username" />
                </StackPanel>
                <StackPanel Margin="0,5,0,0" Orientation="Horizontal">
                    <TextBlock>年龄：</TextBlock>
                    <TextBox Name="userage" Text="14" />
                </StackPanel>
                <StackPanel Margin="0,5,0,0" Orientation="Horizontal">
                    <TextBlock>密码：</TextBlock>
                    <TextBox Name="password" />
                </StackPanel>
                <CheckBox Name="agree" Margin="0,5,0,0" Content="我已阅读并同意用户协议" />
                
                <StackPanel>
                    <StackPanel.Resources>
                        <Style TargetType="TextBlock">
                            <Setter Property="Margin" Value="0,5,0,0" />
                            <Setter Property="FontSize" Value="14" />
                            <Setter Property="Foreground" Value="Red" />
                        </Style>
                    </StackPanel.Resources>                    
                    <TextBlock Visibility="{Binding ElementName=username, Path=Text, Converter={StaticResource UserNameToVisibilityConverter}}">用户名不能为空！</TextBlock>
                    <TextBlock Visibility="{Binding ElementName=userage, Path=Text, Converter={StaticResource AgeToVisibilityConverter}}">年龄需要在18~99之间！</TextBlock>
                    <TextBlock Visibility="{Binding ElementName=password, Path=Text.Length, Converter={StaticResource PasswordLengthToVisibilityConverter}}">密码长度不能小于8位！</TextBlock>
                    <TextBlock Visibility="{Binding ElementName=agree, Path=IsChecked, Converter={StaticResource AgreementToVisibilityConverter}}">您需要勾选同意用户协议！</TextBlock>
                </StackPanel>
            </StackPanel>
        </Border>
    </Grid>
</Window>