创建文件或文件夹

您可通过编程方式在您的计算机上创建文件夹、子文件夹和子文件夹中的文件，并将数据写入文件。

public class CreateFileOrFolder { static void Main() { string folderName = @"c:Top-Level Folder"; string pathString = System.IO.Path.Combine(folderName, "SubFolder"); string pathString2 = @"c:Top-Level FolderSubFolder2"; System.IO.Directory.CreateDirectory(pathString); string fileName = System.IO.Path.GetRandomFileName(); pathString = System.IO.Path.Combine(pathString, fileName); Console.WriteLine("Path to my file: {0}n", pathString); if (!System.IO.File.Exists(pathString)) { using (System.IO.FileStream fs = System.IO.File.Create(pathString)) { for (byte i = 0; i < 100; i++) { fs.WriteByte(i); } } } else { Console.WriteLine("File "{0}" already exists.", fileName); return; } try { byte[] readBuffer = System.IO.File.ReadAllBytes(pathString); foreach (byte b in readBuffer) { Console.Write(b + " "); } Console.WriteLine(); } catch (System.IO.IOException e) { Console.WriteLine(e.Message); } System.Console.WriteLine("Press any key to exit."); System.Console.ReadKey(); } }

输出：

Path to my file: c:Top-Level FolderSubFolderttxvauxe.vv0

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 8 3 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99

如果该文件夹已存在，则 CreateDirectory 不执行任何操作，且不会引发异常。但是，File.Create 用新的文件替换现有文件。该示例使用一个 if-else 语句阻止现有文件被替换。

通过在示例中做出以下更改，您可以根据具有某个名称的程序是否存在来指定不同的结果。如果该文件不存在，代码将创建一个文件。如果该文件存在，代码将把数据添加到该文件中。

指定一个非随机文件名。

// Comment out the following line. //string fileName = System.IO.Path.GetRandomFileName(); // Replace that line with the following assignment. string fileName = "MyNewFile.txt";

用以下代码中的 using 语句替换 if-else 语句。

using (System.IO.FileStream fs = new System.IO.FileStream(pathString, FileMode.Append)) { for (byte i = 0; i < 100; i++) { fs.WriteByte(i); } }

运行该示例若干次以验证数据是否每次都添加到文件中。

复制、删除和移动文件和文件夹

以下示例说明如何使用 System.IO 命名空间中的 System.IO.File、System.IO.Directory、System.IO.FileInfo 和 System.IO.DirectoryInfo 类以同步方式复制、移动和删除文件和文件夹。 这些示例没有提供进度栏或其他任何用户界面。

。

示例

下面的示例演示如何复制文件和目录。

public class SimpleFileCopy { static void Main() { string fileName = "test.txt"; string sourcePath = @"C:UsersPublicTestFolder"; string targetPath = @"C:UsersPublicTestFolderSubDir"; // Use Path class to manipulate file and directory paths. string sourceFile = System.IO.Path.Combine(sourcePath, fileName); string destFile = System.IO.Path.Combine(targetPath, fileName); // To copy a folder's contents to a new location: // Create a new target folder, if necessary. if (!System.IO.Directory.Exists(targetPath)) { System.IO.Directory.CreateDirectory(targetPath); } // To copy a file to another location and // overwrite the destination file if it already exists. System.IO.File.Copy(sourceFile, destFile, true); // To copy all the files in one directory to another directory. // Get the files in the source folder. (To recursively iterate through // all subfolders under the current directory, see // "How to: Iterate Through a Directory Tree.") // Note: Check for target path was performed previously // in this code example. if (System.IO.Directory.Exists(sourcePath)) { string[] files = System.IO.Directory.GetFiles(sourcePath); // Copy the files and overwrite destination files if they already exist. foreach (string s in files) { // Use static Path methods to extract only the file name from the path. fileName = System.IO.Path.GetFileName(s); destFile = System.IO.Path.Combine(targetPath, fileName); System.IO.File.Copy(s, destFile, true); } } else { Console.WriteLine("Source path does not exist!"); } // Keep console window open in debug mode. Console.WriteLine("Press any key to exit."); Console.ReadKey(); } }

下面的示例演示如何移动文件和目录。

public class SimpleFileMove { static void Main() { string sourceFile = @"C:UsersPublicpublictest.txt"; string destinationFile = @"C:UsersPublicprivatetest.txt"; // To move a file or folder to a new location: System.IO.File.Move(sourceFile, destinationFile); // To move an entire directory. To programmatically modify or combine // path strings, use the System.IO.Path class. System.IO.Directory.Move(@"C:UsersPublicpublictest", @"C:UsersPublicprivate"); } }

下面的示例演示如何删除文件和目录。

public class SimpleFileDelete { static void Main() { // Delete a file by using File class static method... if(System.IO.File.Exists(@"C:UsersPublicDeleteTesttest.txt")) { // Use a try block to catch IOExceptions, to // handle the case of the file already being // opened by another process. try { System.IO.File.Delete(@"C:UsersPublicDeleteTesttest.txt"); } catch (System.IO.IOException e) { Console.WriteLine(e.Message); return; } } // ...or by using FileInfo instance method. System.IO.FileInfo fi = new System.IO.FileInfo(@"C:UsersPublicDeleteTesttest2.txt"); try { fi.Delete(); } catch (System.IO.IOException e) { Console.WriteLine(e.Message); } // Delete a directory. Must be writable or empty. try { System.IO.Directory.Delete(@"C:UsersPublicDeleteTest"); } catch (System.IO.IOException e) { Console.WriteLine(e.Message); } // Delete a directory and all subdirectories with Directory static method... if(System.IO.Directory.Exists(@"C:UsersPublicDeleteTest")) { try { System.IO.Directory.Delete(@"C:UsersPublicDeleteTest", true); } catch (System.IO.IOException e) { Console.WriteLine(e.Message); } } // ...or with DirectoryInfo instance method. System.IO.DirectoryInfo di = new System.IO.DirectoryInfo(@"C:UsersPublicpublic"); // Delete this dir and all subdirs. try { di.Delete(true); } catch (System.IO.IOException e) { Console.WriteLine(e.Message); } } }