WPF StringFormat在Label控件无效解决方法

在WPF程序设计时，若使用Label控件绑定数据后StringFormat进行格式化显示时发现设定的StringFormat无效，但TextBlock控件中使用StringFormat显示正常，导致Label控件StringFormat失败的根本原因在于Label控件的Content属性是一个object对象，Binding.StringFormat仅作用于string类型属性。
若需要对Label的Content进行格式化显示，需要使用ContentStringFormat属性来进行单独设置，示例如下：

<Label Content="{Binding Path=MaxLevelofInvestment}" ContentStringFormat="Amount is {0}" />

示例程序

XAML代码：

<Window x:Class="WpfApp5.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:local="clr-namespace:WpfApp5"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800" FontSize="24">
    <Window.Resources>
        <local:DataConext_MainWindow x:Key="DC"/>
    </Window.Resources>
    <Grid DataContext="{StaticResource DC}">
        <Grid.RowDefinitions>
            <RowDefinition/>
            <RowDefinition/>
            <RowDefinition/>
            <RowDefinition/>
        </Grid.RowDefinitions>
        <TextBlock Grid.Row="0" Text="{Binding Width, StringFormat={}{0:F3} }"/>
        <TextBlock Grid.Row="1" Text="{Binding Height, StringFormat={}{0:F2} }"/>
        <Label Grid.Row="2" Content="{Binding Width}" ContentStringFormat="{}{0:F3}"/>
        <Button Grid.Row="3" Content="Modify" Click="Button_Click"/>
    </Grid>
</Window>

cs代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using SAUtil;

namespace WpfApp5
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            var dc = Resources["DC"] as DataConext_MainWindow;
            dc.Height = 12.34556666f;
            dc.Width = 12.34556666;
        }
    }

    public class DataConext_MainWindow : ValidatableModel
    {
        #region Height
        private float _Height = 0;
        public float Height
        {
            get { return _Height; }
            set
            {
                if (_Height == value) return;

                _Height = value;
                RaisePropertyChanged();
            }
        }
        #endregion

        #region Width
        private double _Width = 0;
        public double Width
        {
            get { return _Width; }
            set
            {
                if (_Width == value) return;

                _Width = value;
                RaisePropertyChanged();
            }
        }
        #endregion
    }
}

运行效果

参考资料

https://rotadev.com/wpf-stringformat-on-label-content-dev/