基于DateTime创建自定义GroupDescription [英] Creating custom GroupDescription based on DateTime

问题描述

我正在对一些数据进行分组，并且PropertyGroupDescription在大多数情况下都能正常工作。但是，如果该属性是DateTime，而我又不想将多个日期作为一个组进行分组（例如每组30天左右），则需要一个新的GroupDescription。问题是我不知道该类实际上是如何工作的，以及如何设计这样的类。

I'm grouping some data and PropertyGroupDescription works fine most of the time. However if that property is a DateTime and i wan't to group several dates together as one group (like 30 days in each group or something) I would need a new GroupDescription. Problem is I have no idea how the class actually works and how I would design such a class.

我希望能够继承PropertyGroupDescription（而不是基本的抽象类），因为这也将基于属性，但是在这里，我基于一系列值而不是单个值== 1组进行分组。

I'm hoping to be able to inherit PropertyGroupDescription (instead of the basic abstract class) because this will also be based on a property but here I'm grouping based on a range of values instead of a single value == 1 group.

任何指南甚至是这样的现成课程？

Any guide or even a ready class like this?

推荐答案

有点晚了，但是正如您所说的那样 IValueConverter 可以用于此-这是我使用过的一个简单转换器，它将按友好的相对日期字符串分组：

A bit late, but as you say yourself IValueConverter can be used for this - here's a simple converter I used once that will group by a friendly relative date string:

public class RelativeDateValueConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        var v = value as DateTime?;
        if(v == null) {
            return value;
        }

        return Convert(v.Value);
    }

    public static string Convert(DateTime v)
    {
        var d = v.Date;
        var today = DateTime.Today;
        var diff = today - d;
        if(diff.Days == 0) {
            return "Today";
        }

        if(diff.Days == 1) {
            return "Yesterday";
        }

        if(diff.Days < 7) {
            return d.DayOfWeek.ToString();
        }

        if(diff.Days < 14) {
            return "Last week";
        }

        if(d.Year == today.Year && d.Month == today.Month) {
            return "This month";
        }

        var lastMonth = today.AddMonths(-1);
        if(d.Year == lastMonth.Year && d.Month == lastMonth.Month) {
            return "Last month";
        }

        if(d.Year == today.Year) {
            return "This year";
        }

        return d.Year.ToString(culture);
    }

    public static int Compare(DateTime a, DateTime b)
    {
        return Convert(a) == Convert(b) ? 0 : a.CompareTo(b);
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

然后可以像这样使用它：

You can then use it like this:

view.GroupDescriptions.Add(
    new PropertyGroupDescription("Property", 
        new RelativeDateValueConverter()));

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