Use:

public static class FileInfoExtensions
{
    /// <summary>
    /// Behavior when a new filename exists.
    /// </summary>
    public enum FileExistBehavior
    {
        /// <summary>
        /// None: throw IOException "The destination file already exists."
        /// </summary>
        None = 0,
        /// <summary>
        /// Replace: replace the file in the destination.
        /// </summary>
        Replace = 1,
        /// <summary>
        /// Skip: skip this file.
        /// </summary>
        Skip = 2,
        /// <summary>
        /// Rename: rename the file (like a window behavior)
        /// </summary>
        Rename = 3
    }


    /// <summary>
    /// Rename the file.
    /// </summary>
    /// <param name="fileInfo">the target file.</param>
    /// <param name="newFileName">new filename with extension.</param>
    /// <param name="fileExistBehavior">behavior when new filename is exist.</param>
    public static void Rename(this System.IO.FileInfo fileInfo, string newFileName, FileExistBehavior fileExistBehavior = FileExistBehavior.None)
    {
        string newFileNameWithoutExtension = System.IO.Path.GetFileNameWithoutExtension(newFileName);
        string newFileNameExtension = System.IO.Path.GetExtension(newFileName);
        string newFilePath = System.IO.Path.Combine(fileInfo.Directory.FullName, newFileName);

        if (System.IO.File.Exists(newFilePath))
        {
            switch (fileExistBehavior)
            {
                case FileExistBehavior.None:
                    throw new System.IO.IOException("The destination file already exists.");

                case FileExistBehavior.Replace:
                    System.IO.File.Delete(newFilePath);
                    break;

                case FileExistBehavior.Rename:
                    int dupplicate_count = 0;
                    string newFileNameWithDupplicateIndex;
                    string newFilePathWithDupplicateIndex;
                    do
                    {
                        dupplicate_count++;
                        newFileNameWithDupplicateIndex = newFileNameWithoutExtension + " (" + dupplicate_count + ")" + newFileNameExtension;
                        newFilePathWithDupplicateIndex = System.IO.Path.Combine(fileInfo.Directory.FullName, newFileNameWithDupplicateIndex);
                    }
                    while (System.IO.File.Exists(newFilePathWithDupplicateIndex));

                    newFilePath = newFilePathWithDupplicateIndex;
                    break;

                case FileExistBehavior.Skip:
                    return;
            }
        }
        System.IO.File.Move(fileInfo.FullName, newFilePath);
    }
}

如何使用此代码

class Program
{
    static void Main(string[] args)
    {
        string targetFile = System.IO.Path.Combine(@"D://test", "New Text Document.txt");
        string newFileName = "Foo.txt";

        // Full pattern
        System.IO.FileInfo fileInfo = new System.IO.FileInfo(targetFile);
        fileInfo.Rename(newFileName);

        // Or short form
        new System.IO.FileInfo(targetFile).Rename(newFileName);
    }
}

// Source file to be renamed  
string sourceFile = @"C:\Temp\MaheshChand.jpg";  
// Create a FileInfo  
System.IO.FileInfo fi = new System.IO.FileInfo(sourceFile);  
// Check if file is there  
if (fi.Exists)  
{  
// Move file with a new name. Hence renamed.  
fi.MoveTo(@"C:\Temp\Mahesh.jpg");  
Console.WriteLine("File Renamed.");  
}  

Use:

public static class FileInfoExtensions
{
    /// <summary>
    /// Behavior when a new filename exists.
    /// </summary>
    public enum FileExistBehavior
    {
        /// <summary>
        /// None: throw IOException "The destination file already exists."
        /// </summary>
        None = 0,
        /// <summary>
        /// Replace: replace the file in the destination.
        /// </summary>
        Replace = 1,
        /// <summary>
        /// Skip: skip this file.
        /// </summary>
        Skip = 2,
        /// <summary>
        /// Rename: rename the file (like a window behavior)
        /// </summary>
        Rename = 3
    }


    /// <summary>
    /// Rename the file.
    /// </summary>
    /// <param name="fileInfo">the target file.</param>
    /// <param name="newFileName">new filename with extension.</param>
    /// <param name="fileExistBehavior">behavior when new filename is exist.</param>
    public static void Rename(this System.IO.FileInfo fileInfo, string newFileName, FileExistBehavior fileExistBehavior = FileExistBehavior.None)
    {
        string newFileNameWithoutExtension = System.IO.Path.GetFileNameWithoutExtension(newFileName);
        string newFileNameExtension = System.IO.Path.GetExtension(newFileName);
        string newFilePath = System.IO.Path.Combine(fileInfo.Directory.FullName, newFileName);

        if (System.IO.File.Exists(newFilePath))
        {
            switch (fileExistBehavior)
            {
                case FileExistBehavior.None:
                    throw new System.IO.IOException("The destination file already exists.");

                case FileExistBehavior.Replace:
                    System.IO.File.Delete(newFilePath);
                    break;

                case FileExistBehavior.Rename:
                    int dupplicate_count = 0;
                    string newFileNameWithDupplicateIndex;
                    string newFilePathWithDupplicateIndex;
                    do
                    {
                        dupplicate_count++;
                        newFileNameWithDupplicateIndex = newFileNameWithoutExtension + " (" + dupplicate_count + ")" + newFileNameExtension;
                        newFilePathWithDupplicateIndex = System.IO.Path.Combine(fileInfo.Directory.FullName, newFileNameWithDupplicateIndex);
                    }
                    while (System.IO.File.Exists(newFilePathWithDupplicateIndex));

                    newFilePath = newFilePathWithDupplicateIndex;
                    break;

                case FileExistBehavior.Skip:
                    return;
            }
        }
        System.IO.File.Move(fileInfo.FullName, newFilePath);
    }
}

如何使用此代码

class Program
{
    static void Main(string[] args)
    {
        string targetFile = System.IO.Path.Combine(@"D://test", "New Text Document.txt");
        string newFileName = "Foo.txt";

        // Full pattern
        System.IO.FileInfo fileInfo = new System.IO.FileInfo(targetFile);
        fileInfo.Rename(newFileName);

        // Or short form
        new System.IO.FileInfo(targetFile).Rename(newFileName);
    }
}

添加:

namespace System.IO
{
    public static class ExtendedMethod
    {
        public static void Rename(this FileInfo fileInfo, string newName)
        {
            fileInfo.MoveTo(fileInfo.Directory.FullName + "\\" + newName);
        }
    }
}

然后……

FileInfo file = new FileInfo("c:\test.txt");
file.Rename("test2.txt");

private static void Rename_File(string FileFullPath, string NewName) // nes name without directory actualy you can simply rename with fileinfo.MoveTo(Fullpathwithnameandextension);
        {
            FileInfo fileInfo = new FileInfo(FileFullPath);
            string DirectoryRoot = Directory.GetParent(FileFullPath).FullName;

            string filecreator = FileFullPath.Substring(DirectoryRoot.Length,FileFullPath.Length-DirectoryRoot.Length);
             
            filecreator = DirectoryRoot + NewName;
            try
            {
                fileInfo.MoveTo(filecreator);
            }
            catch(Exception ex)
            {
                Console.WriteLine(filecreator);
                Console.WriteLine(ex.Message);
                Console.ReadKey();
            }

    enter code here
            // string FileDirectory = Directory.GetDirectoryRoot()

        }

在文件中。方法，这将不会覆盖文件，如果它已经存在。它会抛出一个异常。

所以我们需要检查文件是否存在。

/* Delete the file if exists, else no exception thrown. */

File.Delete(newFileName); // Delete the existing file if exists
File.Move(oldFileName,newFileName); // Rename the oldFileName into newFileName

或者用try catch将其包围以避免异常。