扩展的TypeConverter [英] Extend a TypeConverter

问题描述

该DateTimeConverter类提供了日期时间和字符串之间的转换。我也想支持DateTime和双之间的转换。

The DateTimeConverter class provides conversions between DateTime and string. I would also like to support conversions between DateTime and double.

根据MSDN我可以扩展DateTimeConverter类来做到这一点 - 看的 MSDN DateTimeConverter

According to MSDN I can extend the DateTimeConverter class to do this - see MSDN DateTimeConverter

我创建了一个类继承自DateTimeConverter，并提供相应的替换值CanConvertTo，CanConvertFrom等。

I have created a class that inherits from DateTimeConverter and provides the appropriate overrides for CanConvertTo, CanConvertFrom, etc.

我如何确保该框架使用我的日期时间转换器（DateTimeConverterEx），而不是在BCL（DateTimeConverter）中提供的时候，code以下被称为？

How do I make sure that the framework uses my DateTime converter (DateTimeConverterEx) instead of the one provided in the BCL (DateTimeConverter) when the code below is called?

    DateTime dt = DateTime.Now;
    // This line returns a DateTimeConverter which I don't want. 
    // Would like to get a DateTimeConverterEx.
    TypeConverter tc = TypeDescriptor.GetConverter(dt);
    double dbl = (double)tc.ConvertTo(dt, typeof(double));

感谢。

推荐答案

您需要分配的转换器。在属性按属性的基础上，你可以使用：

You need to allocate the converter. On a property-by-property basis, you can use:

[TypeConverter(typeof(DateTimeConverterEx))]
public DateTime Foo {get {...} set {...}}

这将然后工作表单的使用：

This would then work for usage of the form:

var prop = TypeDescriptor.GetProperties(obj)["Foo"];
var converter = prop.Converter;
// as before, using "converter"

这将适用于最常见的绑定方案。

This will work for most common binding scenarios.

（修改）

要设置转换器的任何 的DateTime ：

TypeDescriptor.AddAttributes(typeof(DateTime),
    new TypeConverterAttribute(typeof(DateTimeConverterEx)));

现在你的样品code应该工作。

Now your sample code should work.

这篇关于扩展的TypeConverter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！