C＃Array.ConvertAll for compact framework

Question

据我所知，.NET Compact Framework没有Array.ConvertAll()。在CF中执行Array.ConvertAll()的最佳方法是什么？

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。

Answer 1

可以使用LINQ表达式：

var result = input.Select(converter).ToArray(); 

Answer 2

此外，您还可以使用reflector来获得在实施，这原来是这样的：

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; 
} 

Answer 3

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

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

// 
// 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; 
} 

因为而寻找与反射器/ ilspy的.NET的合法性是灰色区域，逐字拷贝的代码是可靠地在错误的一侧。

（请注意，我已经添加了文件的版权，这个版本比代码要大得多:-)，因为从技术上讲，如果您想使用那么一小段代码，您必须尊重它的许可证，是MIT许可证）

Answer 4

对于.NET的核心，这将是有用的：

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; 
}