类型转换器在绑定到ASP.NET的GridView [英] TypeConverter when binding to ASP.NET GridView

问题描述

我试图将对象绑定到一个GridView的DataSource的一个IList和对象的属性之一是枚举。我试图用的TypeConverter在枚举使用说明当对象绑定到GridView行。它看起来并不像我 EnumConverter.ConvertTo 方法被调用。将一个类型转换器被自动调用当对象被绑定到一个ASP.NET的GridView？

ENUM：

  [类型转换器（typeof运算（AuditReasonConverter））]
    公共枚举AuditReason
    {
        [System.ComponentModel.Description（成功登录）
        SuccessfulLogin，
        [System.ComponentModel.Description（登录失败）
        FailedLogin，
        [System.ComponentModel.Description（新用户）]
        新用户，
        [System.ComponentModel.Description（编辑用户）]
        EditedUser
    }
 

类型转换器类：

 公共类AuditReasonConverter：EnumConverter
    {
        公共AuditReasonConverter（）
            ： 基础（
                typeof运算（Blah.Core.AuditItem.AuditReason））
        {}

        公众覆盖对象的ConvertTo（ITypeDescriptorContext的背景下，
            System.Globalization.CultureInfo文化，对象的值，
            System.Type的destinationType）
        {
            如果（destinationType == typeof运算（字符串））
            {
                返回Utilities.GetEnumerationDescription（typeof运算（Blah.Core.AuditItem.AuditReason），价值）; //你的code在这里
            }
            返回base.ConvertTo（上下文，文化，价值，destinationType）;
        }
    }
 

解决方案

没有，GridView控件似乎只是去的ToString。

我所做的不过是子类绑定列（或的DataControlField =更多的工作），并使用在FormatDataValue你的转换器 -

 公共类ConverterBoundField：绑定列
{
    保护覆盖字符串FormatDataValue（对象dataValue，布尔EN code）
    {
        的TypeConverter变换器= TypeDescriptor.GetConverter（dataValue.GetType（））;
        如果（converter.CanConvertTo（typeof运算（字符串）））
        {
            返回converter.ConvertToString（da​​taValue）;
        }
        返回base.FormatDataValue（dataValue，EN code）;

    }
}
 

您也许应该尊重EN code参数，并做所指定的任何格式...这可能是最好的实现CanConvertTo你的转换器还。

I am trying to bind an IList of objects to a GridView's DataSource and one of the properties of the object is an enum. I was trying to use a TypeConverter on the enum to use a Description when the object is bound to the GridView Row. It does not look like my EnumConverter.ConvertTo method is being called. Will a TypeConverter be called automatically when the object is being bound to an ASP.NET GridView?

ENUM:

[TypeConverter(typeof(AuditReasonConverter))]
    public enum AuditReason
    {
        [System.ComponentModel.Description("Successful Login")]
        SuccessfulLogin,
        [System.ComponentModel.Description("Failed Login")]
        FailedLogin,
        [System.ComponentModel.Description("New User")]
        NewUser,
        [System.ComponentModel.Description("Edited User")]
        EditedUser
    }

TypeConverter Class:

public class AuditReasonConverter : EnumConverter
    {
        public AuditReasonConverter()
            : base(
                typeof(Blah.Core.AuditItem.AuditReason))
        { }

        public override object ConvertTo(ITypeDescriptorContext context,
            System.Globalization.CultureInfo culture, object value,
            System.Type destinationType)
        {
            if (destinationType == typeof(string))
            {
                return Utilities.GetEnumerationDescription(typeof(Blah.Core.AuditItem.AuditReason), value);  // your code here
            }
            return base.ConvertTo(context, culture, value, destinationType);
        }
    }

解决方案

No, GridView seems to just go for ToString.

What I have done though is subclass BoundField (or DataControlField = more work) and use your converter in FormatDataValue -

public class ConverterBoundField : BoundField
{
    protected override string FormatDataValue(object dataValue, bool encode)
    {
        TypeConverter converter = TypeDescriptor.GetConverter(dataValue.GetType());
        if (converter.CanConvertTo(typeof(string)))
        {
            return converter.ConvertToString(dataValue);
        }
        return base.FormatDataValue(dataValue, encode);

    }
}

You should probably respect the encode parameter, and do any formatting that was specified... and it is probably best to implement CanConvertTo for your converter also.

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