c#使用file.copy实现文件备份示例

步骤：

1、遍历d盘source文件夹找出所有名称包含lte的文件，文件路径存放到list<string>中
2、遍历list<string>,把所有文件copy到e盘的备份文件夹中

using system;
using system.collections.generic;
using system.linq;
using system.text;
using system.directoryservices;
using system.io;

namespace copylte
{
    class program
    {
        static void main(string[] args)
        {
            try
            {
                string txtpath = @"..\..\dir\directory.txt";
                string srcpath = "";
                string aimpath = "";
                string keywords = "";
                list<string> keyfloderlist = new list<string>();
                if (file.exists(txtpath) == false)
                {
                    console.writeline("directory.txt不存在,無法獲取copy路徑");
                }
                else
                {
                    getcopypath(txtpath, out srcpath, out aimpath, out keywords);
                    if (srcpath == "" || aimpath == "" || keywords == "")
                    {
                        console.writeline("請在directory.txt,輸入copy的源文件夾,目的文件,和keywords");
                    }
                    else
                    {
                        directoryinfo foldersource = new directoryinfo(srcpath);
                        foreach (directoryinfo nextfolder in foldersource.getdirectories())
                        {
                            if (nextfolder.fullname.contains(keywords))
                            {
                                keyfloderlist.add(nextfolder.fullname);
                            }
                        }
                    }
                }
                if (keyfloderlist.count > 0)
                {
                    foreach (string floderpath in keyfloderlist)
                    {
                        //copy from source to backup
                        copydirectory(floderpath, aimpath);
                    }
                }
            }
            catch (exception ex)
            {
                throw ex;
            }
        }

        //
        private static void copydirectory(string srcdir, string desdir)
        {
            string foldername = srcdir.substring(srcdir.lastindexof("\\") + 1);

            string desfolderdir = desdir + "\\" + foldername;

            if (desdir.lastindexof("\\") == (desdir.length - 1))
            {
                desfolderdir = desdir + foldername;
            }
            string[] filenames = directory.getfilesystementries(srcdir);

            foreach (string file in filenames)// 遍历所有的文件和目录
            {
                if (directory.exists(file))// 先当作目录处理如果存在这个目录就递归copy该目录下面的文件
                {

                    string currentdir = desfolderdir + "\\" + file.substring(file.lastindexof("\\") + 1);
                    if (!directory.exists(currentdir))
                    {
                        directory.createdirectory(currentdir);
                    }

                    copydirectory(file, desfolderdir);
                }

                else // 否则直接copy文件
                {
                    string srcfilename = file.substring(file.lastindexof("\\") + 1);

                    srcfilename = desfolderdir + "\\" + srcfilename;
                    if (file.exists(srcfilename))
                    {
                        file.delete(srcfilename); //delete old files
                    }

                    if (!directory.exists(desfolderdir))
                    {
                        directory.createdirectory(desfolderdir);
                    }
                    file.copy(file, srcfilename);
                }
            }
        }
        //取得路徑
        public static void getcopypath(string strtxt, out string from, out string to, out string keywords)
        {
            try
            {
                string[] stringlines = file.readalllines(strtxt, encoding.default);
                if (stringlines.length >= 3)
                {
                    from = stringlines[0].tostring();
                    to = stringlines[1].tostring();
                    keywords = stringlines[2].tostring();
                }
                else
                {
                    from = "";
                    to = "";
                    keywords = "";
                    console.writeline("請在directory.txt,輸入copy的源文件夾,目的文件,和keywords");
                }
            }
            catch (exception ex)
            {
                throw ex;
            }
        }
    }
}