自定义样式例子

代码

    <Application.Resources>
        <Style x:Key="styledTextBox" TargetType="{x:Type TextBox}">
            <Setter Property="HorizontalAlignment" Value="Left" />
            <Setter Property="Height" Value="28" />
            <Setter Property="Foreground" Value="White" />
            <Setter Property="CaretBrush" Value="White" />
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="{x:Type TextBox}">
                        <Border
                            Background="#0A5D7B"
                            BorderBrush="#eee"
                            BorderThickness="0"
                            CornerRadius="2">
                            <Grid>
                                <Border
                                    x:Name="BorderBase"
                                    Background="Transparent"
                                    BorderBrush="Transparent"
                                    BorderThickness="1.4,1.4,1,1" />
                                <Label
                                    x:Name="TextPrompt"
                                    VerticalAlignment="Center"
                                    Content="{TemplateBinding Tag}"
                                    Focusable="False"
                                    Foreground="Gray"
                                    Visibility="Collapsed" />
                                <ScrollViewer
                                    x:Name="PART_ContentHost"
                                    Margin="2,0,0,0"
                                    VerticalAlignment="Center" />
                            </Grid>
                        </Border>
                        <ControlTemplate.Triggers>
                            <MultiTrigger>
                                <MultiTrigger.Conditions>
                                    <Condition Property="IsFocused" Value="False" />
                                    <Condition Property="Text" Value="" />
                                </MultiTrigger.Conditions>
                                <Setter TargetName="TextPrompt" Property="Visibility" Value="Visible" />
                            </MultiTrigger>
                            <Trigger Property="IsFocused" Value="True">
                                <Setter TargetName="BorderBase" Property="BorderThickness" Value="2.4,1.4,1,1" />
                            </Trigger>
                            <Trigger Property="IsEnabled" Value="False">
                                <Setter Property="Foreground" Value="Gray" />
                            </Trigger>
                        </ControlTemplate.Triggers>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>
    </Application.Resources>

            <TextBox
                Width="222"
                Height="23"
                Style="{StaticResource styledTextBox}"
                Text="New TextBox"
                TextWrapping="Wrap" />

效果

提示字符串效果

代码

       <TextBox
            Width="200"
            Height="30"
            HorizontalAlignment="Center"
            VerticalAlignment="Center"
            VerticalContentAlignment="Center">
            <TextBox.Style>
                <Style xmlns:sys="clr-namespace:System;assembly=mscorlib" TargetType="TextBox">
                    <Style.Resources>
                        <VisualBrush
                            x:Key="CueBannerBrush"
                            AlignmentX="Left"
                            AlignmentY="Center"
                            Stretch="None">
                            <VisualBrush.Visual>
                                <Label Content="你的提示字符串" Foreground="LightGray" />
                            </VisualBrush.Visual>
                        </VisualBrush>
                    </Style.Resources>
                    <Style.Triggers>
                        <Trigger Property="Text" Value="{x:Static sys:String.Empty}">
                            <Setter Property="Background" Value="{StaticResource CueBannerBrush}" />
                        </Trigger>
                        <Trigger Property="Text" Value="{x:Null}">
                            <Setter Property="Background" Value="{StaticResource CueBannerBrush}" />
                        </Trigger>
                        <Trigger Property="IsKeyboardFocused" Value="True">
                            <Setter Property="Background" Value="White" />
                        </Trigger>
                    </Style.Triggers>
                </Style>
            </TextBox.Style>
        </TextBox>

效果

另一种方式

如果你的工程里引用了MaterialDesignUI库的话，下面的方式更简单：

            <TextBox
                Name="txtStock"
                Grid.Row="0"
                Grid.Column="2"
                materialDesign:HintAssist.Hint="你的提示字符串"
                MaxLength="16"
                Text="{Binding StockCode}" />

自动高亮选中功能

代码

    <Grid>
        <TextBox
            Name="MyBox"
            Width="200"
            Height="23"
            GotFocus="UIElement_OnGotFocus"
            Text="sample text" />
    </Grid>

        private void UIElement_OnGotFocus(object sender, RoutedEventArgs e)
        {
            var textBox = (TextBox)sender;
            textBox.Dispatcher.BeginInvoke(new Action(() => textBox.SelectAll()));
        }

效果