内联转换:我喜欢这个小模式。完成了Boolean, Double和DateTime。设计遵循c#的is和作为操作符。

public static Int32? AsInt32(this string s)
{
    Int32 value;
    if (Int32.TryParse(s, out value))
        return value;

    return null;
}

public static bool IsInt32(this string s)
{
    return s.AsInt32().HasValue;
}

public static Int32 ToInt32(this string s)
{
    return Int32.Parse(s);
{

没有检查整个线程，所以它可能已经在这里，但是:

public static class FluentOrderingExtensions
    public class FluentOrderer<T> : IEnumerable<T>
    {
        internal List<Comparison<T>> Comparers = new List<Comparison<T>>();

        internal IEnumerable<T> Source;

        public FluentOrderer(IEnumerable<T> source)
        {
            Source = source;
        }

        #region Implementation of IEnumerable

        public IEnumerator<T> GetEnumerator()
        {
            var workingArray = Source.ToArray();
            Array.Sort(workingArray, IterativeComparison);

            foreach(var element in workingArray) yield return element;
        }

        private int IterativeComparison(T a, T b)
        {
            foreach (var comparer in Comparers)
            {
                var result = comparer(a,b);
                if(result != 0) return result;
            }
            return 0;
        }

        IEnumerator IEnumerable.GetEnumerator()
        {
            return GetEnumerator();
        }

        #endregion
    }

    public static FluentOrderer<T> OrderFluentlyBy<T,TResult>(this IEnumerable<T> source, Func<T,TResult> predicate) 
        where TResult : IComparable<TResult>
    {
        var result = new FluentOrderer<T>(source);
        result.Comparers.Add((a,b)=>predicate(a).CompareTo(predicate(b)));
        return result;
    }

    public static FluentOrderer<T> OrderFluentlyByDescending<T,TResult>(this IEnumerable<T> source, Func<T,TResult> predicate) 
        where TResult : IComparable<TResult>
    {
        var result = new FluentOrderer<T>(source);
        result.Comparers.Add((a,b)=>predicate(a).CompareTo(predicate(b)) * -1);
        return result;
    }

    public static FluentOrderer<T> ThenBy<T, TResult>(this FluentOrderer<T> source, Func<T, TResult> predicate)
        where TResult : IComparable<TResult>
    {
        source.Comparers.Add((a, b) => predicate(a).CompareTo(predicate(b)));
        return source;
    }

    public static FluentOrderer<T> ThenByDescending<T, TResult>(this FluentOrderer<T> source, Func<T, TResult> predicate)
        where TResult : IComparable<TResult>
    {
        source.Comparers.Add((a, b) => predicate(a).CompareTo(predicate(b)) * -1);
        return source;
    }
}

用法:

var myFluentlyOrderedList = GetABunchOfComplexObjects()
    .OrderFluentlyBy(x=>x.PropertyA)
    .ThenByDescending(x=>x.PropertyB)
    .ThenBy(x=>x.SomeMethod())
    .ThenBy(x=>SomeOtherMethodAppliedTo(x))
    .ToList();

．.． 当然，假设所有的谓词都返回与自身icomcomparable的类型。如果使用像MergeSort这样的稳定排序，而不是。net内置的快速排序，它会更好地工作，但它提供了类似于SQL的可读多字段排序能力(无论如何，它是方法链所能获得的最接近的功能)。您可以通过定义重载来接受比较lambda，而不是基于谓词创建它，从而扩展它以容纳非IComparable的成员。

EDIT: A little explanation, since the commenter got some upticks: this set of methods improves upon the basic OrderBy() functionality by allowing you to sort based on multiple fields in descending order of importance. A real-world example would be sorting a list of invoices by customer, then by invoice number (or invoice date). Other methods of getting the data in this order either wouldn't work (OrderBy() uses an unstable sort, so it cannot be chained) or would be inefficient and not look like it does what you're trying to do.

有时需要有类的实例，不管是否有效，但不是null

public static T Safe<T>(this T obj) where T : new()
{
    if (obj == null)
    {
        obj = new T();
    }

    return obj;
}

用法如下:

MyClass myClass = Provider.GetSomeResult();
string temp = myClass.Safe().SomeValue;

而不是:

MyClass myClass = Provider.GetSomeResult();
string temp = "some default value";
if (myClass != null)
{
        temp = myClass.SomeValue;
}

如果是口是心非的话，我很抱歉，但我没有找到。

我一直在寻找一种方式来回馈社区我所开发的一些东西。

这里有一些FileInfo扩展，我觉得非常有用。

/// <summary>
/// Open with default 'open' program
/// </summary>
/// <param name="value"></param>
public static Process Open(this FileInfo value)
{
    if (!value.Exists)
        throw new FileNotFoundException("File doesn't exist");
    Process p = new Process();
    p.StartInfo.FileName = value.FullName;
    p.StartInfo.Verb = "Open";
    p.Start();
    return p;
}

/// <summary>
/// Print the file
/// </summary>
/// <param name="value"></param>
public static void Print(this FileInfo value)
{
    if (!value.Exists)
        throw new FileNotFoundException("File doesn't exist");
    Process p = new Process();
    p.StartInfo.FileName = value.FullName;
    p.StartInfo.Verb = "Print";
    p.Start();
}

/// <summary>
/// Send this file to the Recycle Bin
/// </summary>
/// <exception cref="File doesn't exist" />
/// <param name="value"></param>
public static void Recycle(this FileInfo value)
{        
    value.Recycle(false);
}

/// <summary>
/// Send this file to the Recycle Bin
/// On show, if person refuses to send file to the recycle bin, 
/// exception is thrown or otherwise delete fails
/// </summary>
/// <exception cref="File doesn't exist" />
/// <exception cref="On show, if user refuses, throws exception 'The operation was canceled.'" />
/// <param name="value">File being recycled</param>
/// <param name="showDialog">true to show pop-up</param>
public static void Recycle(this FileInfo value, bool showDialog)
{
    if (!value.Exists)
            throw new FileNotFoundException("File doesn't exist");
    if( showDialog )
        FileSystem.DeleteFile
            (value.FullName, UIOption.AllDialogs, 
            RecycleOption.SendToRecycleBin);
    else
        FileSystem.DeleteFile
            (value.FullName, UIOption.OnlyErrorDialogs, 
            RecycleOption.SendToRecycleBin);
}

在用户喜欢的编辑器中打开任意文件:

new FileInfo("C:\image.jpg").Open();

打印任何操作系统知道如何打印的文件:

new FileInfo("C:\image.jpg").Print();

将任何文件发送到回收站:

你必须包括微软。VisualBasic参考 使用Microsoft.VisualBasic.FileIO;

例子:

new FileInfo("C:\image.jpg").Recycle();

Or

// let user have a chance to cancel send to recycle bin.
new FileInfo("C:\image.jpg").Recycle(true);

在。net中，有IndexOf和LastIndexOf方法，它们返回String对象中第一个和最后一个匹配项的索引。我有一个扩展方法来获得第n次出现的索引:

public static partial class StringExtensions {

    public static int NthIndexOf(this String str, String match, int occurrence) {
        int i = 1;
        int index = 0;

        while (i <= occurrence && 
            ( index = str.IndexOf(match, index + 1) ) != -1) {

            if (i == occurrence) {
                // Occurrence match found!
                return index;
            }
            i++;
        }

        // Match not found
        return -1;
    }
}

与时间跨度相关的扩展，如:

public static TimeSpan Seconds(this int seconds)
{
  return TimeSpan.FromSeconds(seconds);
}

public static TimeSpan Minutes(this int minutes)
{
  return TimeSpan.FromMinutes(minutes);
}

允许使用:

1.Seconds()
20.Minutes()

像这样的锁定扩展:

public static IDisposable GetReadLock(this ReaderWriterLockSlim slimLock)
{
  slimLock.EnterReadLock();
  return new DisposableAction(slimLock.ExitReadLock);
}

public static IDisposable GetWriteLock(this ReaderWriterLockSlim slimLock)
{
  slimLock.EnterWriteLock();
  return new DisposableAction(slimLock.ExitWriteLock);
}

public static IDisposable GetUpgradeableReadLock(this ReaderWriterLockSlim slimLock)
{
  slimLock.EnterUpgradeableReadLock();
  return new DisposableAction(slimLock.ExitUpgradeableReadLock);
}

允许使用像这样的锁:

using (lock.GetUpgradeableReadLock())
{
  // try read
  using (lock.GetWriteLock())
  {
    //do write
  }
}

还有许多来自Lokad共享图书馆的其他书籍