WPF:将布尔值显示为“是"；/“不" [英] WPF: Display a bool value as "Yes" / "No"

问题描述

我有一个布尔值，需要在 TextBlock 中显示为是"或否".我正在尝试使用 StringFormat 执行此操作，但我的 StringFormat 被忽略并且 TextBlock 显示True"或False".

I have a bool value that I need to display as "Yes" or "No" in a TextBlock. I am trying to do this with a StringFormat, but my StringFormat is ignored and the TextBlock displays "True" or "False".

<TextBlock Text="{Binding Path=MyBoolValue, StringFormat='{}{0:Yes;;No}'}" />

我的语法有问题，还是不支持这种类型的 StringFormat?

Is there something wrong with my syntax, or is this type of StringFormat not supported?

我知道我可以使用 ValueConverter 来完成此操作，但 StringFormat 解决方案似乎更优雅(如果有效的话).

I know I can use a ValueConverter to accomplish this, but the StringFormat solution seems more elegant (if it worked).

推荐答案

您使用 StringFormat 的解决方案无法工作，因为它不是有效的格式字符串.

Your solution with StringFormat can't work, because it's not a valid format string.

我写了一个标记扩展来满足你的需求.你可以这样使用它:

I wrote a markup extension that would do what you want. You can use it like that :

<TextBlock Text="{my:SwitchBinding MyBoolValue, Yes, No}" />

这里是标记扩展的代码:

Here the code for the markup extension :

public class SwitchBindingExtension : Binding
{
    public SwitchBindingExtension()
    {
        Initialize();
    }

    public SwitchBindingExtension(string path)
        : base(path)
    {
        Initialize();
    }

    public SwitchBindingExtension(string path, object valueIfTrue, object valueIfFalse)
        : base(path)
    {
        Initialize();
        this.ValueIfTrue = valueIfTrue;
        this.ValueIfFalse = valueIfFalse;
    }

    private void Initialize()
    {
        this.ValueIfTrue = Binding.DoNothing;
        this.ValueIfFalse = Binding.DoNothing;
        this.Converter = new SwitchConverter(this);
    }

    [ConstructorArgument("valueIfTrue")]
    public object ValueIfTrue { get; set; }

    [ConstructorArgument("valueIfFalse")]
    public object ValueIfFalse { get; set; }

    private class SwitchConverter : IValueConverter
    {
        public SwitchConverter(SwitchBindingExtension switchExtension)
        {
            _switch = switchExtension;
        }

        private SwitchBindingExtension _switch;

        #region IValueConverter Members

        public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            try
            {
                bool b = System.Convert.ToBoolean(value);
                return b ? _switch.ValueIfTrue : _switch.ValueIfFalse;
            }
            catch
            {
                return DependencyProperty.UnsetValue;
            }
        }

        public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            return Binding.DoNothing;
        }

        #endregion
    }

}

这篇关于WPF:将布尔值显示为“是"；/“不"的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！