0

据我所知Array.ConvertAll()，.NET Compact Framework 没有。Array.ConvertAll()在 CF中做一个最好的方法是什么？

public static string DataRowToString(DataRow dr)
{
    return dr["columns"].ToString();
}

public static string[] DataTableToArray(DataTable dt)
{
    var dr = dt.Select();
    string[] strArr = Array.ConvertAll(dr, new System.Converter<DataRow, string>(DataRowToString));
    return strArr;
}

上面的代码在 CF 中不起作用。

4

4 回答 4

3

您可以使用 LINQ 表达式：

var result = input.Select(converter).ToArray();
于 2013-08-19T11:25:25.967 回答
1

此外，您可以使用reflector它来实现，结果如下所示：

public static TOutput[] ConvertAll<TInput, TOutput>(TInput[] array, Converter<TInput, TOutput> converter)
{
    if (array == null)
    {
        throw new ArgumentNullException("array");
    }

    if (converter == null)
    {
        throw new ArgumentNullException("converter");
    }

    TOutput[] localArray = new TOutput[array.Length];

    for (int i = 0; i < array.Length; i++)
    {
        localArray[i] = converter(array[i]);
    }

    return localArray;
}
于 2013-08-19T11:26:55.797 回答
0

当我有这些问题，我想感觉“干净”时，我通常会看Project Mono的好人做了什么。

（我有我的本地副本，所以我可以直接查找Array.cs）...现在让我们看看。

//
// System.Array.cs
//
// Authors:
//   Joe Shaw (joe@ximian.com)
//   Martin Baulig (martin@gnome.org)
//   Dietmar Maurer (dietmar@ximian.com)
//   Gonzalo Paniagua Javier (gonzalo@ximian.com)
//   Jeffrey Stedfast (fejj@novell.com)
//   Marek Safar (marek.safar@gmail.com)
//
// (C) 2001-2003 Ximian, Inc.  http://www.ximian.com
// Copyright (C) 2004-2011 Novell, Inc (http://www.novell.com)
// Copyright (C) 2011 Xamarin Inc (http://www.xamarin.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
// 
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

public static TOutput[] ConvertAll<TInput, TOutput> (TInput [] array, Converter<TInput, TOutput> converter)
{
    if (array == null)
        throw new ArgumentNullException ("array");
    if (converter == null)
        throw new ArgumentNullException ("converter");

    TOutput [] output = new TOutput [array.Length];
    for (int i = 0; i < array.Length; i ++)
        output [i] = converter (array [i]);

    return output;
}

因为虽然使用反射器/ilspy 查看 .NET 的合法性是一个灰色区域，但逐字复制代码肯定是错误的。

（请注意，我已经添加了文件的版权，仅此一项就比代码大得多 :-)，因为从技术上讲，如果您想使用那一小段代码，则必须尊重其许可，即 MIT 许可)

于 2013-08-19T11:41:19.807 回答
0

对于 .NET Core，这将很有用：

public static TOut[] ConvertAll<TIn, TOut>(this TIn[] thisArray, Func<TIn, TOut> converter)
{
    if (thisArray == null)
        throw new ArgumentNullException(nameof(thisArray));

    if (converter == null)
        throw new ArgumentNullException(nameof(converter));

    TOut[] revVal = new TOut[thisArray.Length];

    for (int i = 0; i < thisArray.Length; i++)
        revVal[i] = converter(thisArray[i]);

    return revVal;
}
于 2016-10-20T21:51:42.730 回答