public static void CopyTest()
    {
        string sourceFolderName = "F:/test2";
        string destFolderName = "F:/test1";

        CopyFileToFile(sourceFolderName, destFolderName, true);
    }

    /// <summary>
    /// 把 文件夹下的所有文件拷贝到指定文件夹
    /// </summary>
    public static void CopyFileToFile(string sourceFolderName, string destFolderName, bool overwrite)
    {
        if (Directory.Exists(destFolderName))
        {
            DelectDir(destFolderName);
        }
        CopySubFun(sourceFolderName, destFolderName, true);
    }

    public static void CopySubFun(string sourceFolderName, string destFolderName, bool overwrite)
    {
        if (!Directory.Exists(sourceFolderName))
        {
            return;
        }
        if (!Directory.Exists(destFolderName))
        {
            Directory.CreateDirectory(destFolderName);
        }
    
        string[] sourceFilesPath = Directory.GetFileSystemEntries(sourceFolderName);

        for (int i = 0; i < sourceFilesPath.Length; i++)
        {
            string sourceFilePath = (sourceFilesPath[i]).Replace("\\", "/");
            string[] forlders = sourceFilePath.Split('/');
          
            if (File.Exists(sourceFilePath))//是文件,直接拷贝
            {
                string dest = destFolderName;
                string sourceFileName = Path.GetFileName(sourceFilePath);
                File.Copy(sourceFilePath, Path.Combine(dest, sourceFileName), overwrite);
            }
            else if (Directory.Exists(sourceFilePath))//是文件夹,拷贝文件夹;并递归
            {
                string lastDirectory = forlders[forlders.Length - 1];
                string dest = Path.Combine(destFolderName, lastDirectory).Replace("\\", "/");

                if (!Directory.Exists(dest))
                {
                    Directory.CreateDirectory(dest);
                }
                CopySubFun(sourceFilePath, dest, overwrite);
            }
        }
    }

public static void DelectDir(string srcPath)
{

DirectoryInfo dir = new DirectoryInfo(srcPath);
FileSystemInfo[] fileinfo = dir.GetFileSystemInfos(); //返回目录中所有文件和子目录
foreach (FileSystemInfo i in fileinfo)
{
if (i is DirectoryInfo) //判断是否文件夹
{
DirectoryInfo subdir = new DirectoryInfo(i.FullName);
subdir.Delete(true); //删除子目录和文件
}
else
{
File.Delete(i.FullName); //删除指定文件
}
}

}