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查找現有的文件和目錄

您還可以使用獨立存儲文件來搜索現有的目錄和文件。請記住，在存儲區中，文件名和目錄名是相對于虛文件系統的根目錄指定的。此外，Windows 文件系統中的文件和目錄名不區分大小寫。
要搜索某個目錄，請使用 IsolatedStorageFile 的 GetDirectoryNames 實例方法。GetDirectoryNames 采用表示搜索模式的字符串。支持使用單字符 (?) 和多字符 (*) 通配符。這些通配符不能出現在名稱的路徑部分。也就是說，directory1/*ect* 是有效的搜索字符串，而 *ect*/directory2 不是有效的搜索字符串。
要搜索某個文件，請使用 IsolatedStorageFile 的 GetFileNames 實例方法。對應用于 GetDirectoryNames 的搜索字符串中通配符的相同限制也適用于 GetFileNames。
GetDirectoryNames 和 GetFileNames 都不是遞歸的，即 IsolatedStorageFile 不提供用于列出存儲區中所有目錄或文件的方法。但是，下面的代碼中部分是遞歸方法的示例。另外還要注意，GetDirectoryNames 和 GetFileNames 只返回找到的項的目錄名或文件名。例如，如果找到目錄 RootDir/SubDir/SubSubDir 的匹配項，結果數組中將返回 SubSubDir。

FindingExistingFilesAndDirectories 示例

下面的代碼示例闡釋如何在獨立存儲區創建文件和目錄。首先，檢索一個按用戶、域和程序集隔離的存儲區并放入 isoStore 變量。CreateDirectory 方法用于設置幾個不同的目錄，IsolatedStorageFileStream 方法在這些目錄中創建一些文件。然后，代碼依次通過 GetAllDirectories 方法的結果。該方法使用 GetDirectoryNames 來查找當前目錄中的所有目錄名。這些名稱存儲在數組中，然后 GetAllDirectories 調用其本身，傳入它所找到的每個目錄。結果是在數組中返回的所有目錄名。然后，代碼調用 GetAllFiles 方法。該方法調用 GetAllDirectories 以查找所有目錄的名稱，然后它檢查每個目錄以查找使用 GetFileNames 方法的文件。結果返回到數組中用于顯示。

 [C#]

using System;

using System.IO;

using System.IO.IsolatedStorage;

using System.Collections;

public class FindingExistingFilesAndDirectories{

 // Retrieves an array of all directories in the store, and

 // displays the results.

 public static void Main(){

// This part of the code sets up a few directories and files in the

// store.

IsolatedStorageFile isoStore = IsolatedStorageFile.GetStore(IsolatedStorageScope.User | IsolatedStorageScope.Assembly, null, null);

isoStore.CreateDirectory("TopLevelDirectory");

isoStore.CreateDirectory("TopLevelDirectory/SecondLevel");

isoStore.CreateDirectory("AnotherTopLevelDirectory/InsideDirectory");

new IsolatedStorageFileStream("InTheRoot.txt", FileMode.Create, isoStore);

new IsolatedStorageFileStream("AnotherTopLevelDirectory/InsideDirectory/HereIAm.txt", FileMode.Create, isoStore);

// End of setup.

Console.WriteLine('\r');

Console.WriteLine("Here is a list of all directories in this isolated store:");

foreach(string directory in GetAllDirectories("*", isoStore)){

 Console.WriteLine(directory);

Console.WriteLine('\r');

// Retrieve all the files in the directory by calling the GetFiles

// method.

Console.WriteLine("Here is a list of all the files in this isolated store:");

foreach(string file in GetAllFiles("*", isoStore)){

 Console.WriteLine(file);

 }// End of Main.

 // Method to retrieve all directories, recursively, within a store.

 public static string[] GetAllDirectories(string pattern, IsolatedStorageFile storeFile){

// Get the root of the search string.

string root = Path.GetDirectoryName(pattern);

if (root != "") root += "/";

// Retrieve directories.

string[] directories;

directories = storeFile.GetDirectoryNames(pattern);

ArrayList directoryList = new ArrayList(directories);

// Retrieve subdirectories of matches.

for (int i = 0, max = directories.Length; i < max; i++){

 string directory = directoryList[i] + "/";

 string[] more = GetAllDirectories (root + directory + "*", storeFile);

 // For each subdirectory found, add in the base path.

 for (int j = 0; j < more.Length; j++)

more[j] = directory + more[j];

 // Insert the subdirectories into the list and

 // update the counter and upper bound.

 directoryList.InsertRange(i+1, more);

 i += more.Length;

 max += more.Length;

return (string[])directoryList.ToArray(Type.GetType("System.String"));

 public static string[] GetAllFiles(string pattern, IsolatedStorageFile storeFile){

// Get the root and file portions of the search string.

string fileString = Path.GetFileName(pattern);

string[] files;

files = storeFile.GetFileNames(pattern);

ArrayList fileList = new ArrayList(files);

// Loop through the subdirectories, collect matches,

// and make separators consistent.

foreach(string directory in GetAllDirectories( "*", storeFile))

 foreach(string file in storeFile.GetFileNames(directory + "/" + fileString))

fileList.Add((directory + "/" + file));

return (string[])fileList.ToArray(Type.GetType("System.String"));

 }// End of GetFiles.

讀取和寫入文件

使用 IsolatedStorageFileStream 類，有多種方法可以打開存儲區中的文件。一旦獲得了 IsolatedStorageFileStream 之后，可使用它來獲取 StreamReader 或 StreamWriter。使用 StreamReader 和 StreamWriter，您可以像對任何其他文件一樣讀取和寫入存儲區中的文件。

ReadingAndWritingToFiles 示例

下面的代碼示例獲得獨立存儲區，創建一個名為 TestStore.txt 的文件并將“Hello Isolated Storage”寫入文件。然后，代碼讀取該文件并將結果輸出到控制臺。

 [C#]

using System;

using System.IO;

using System.IO.IsolatedStorage;

public class ReadingAndWritingToFiles{

 public static int Main(){

// Get an isolated store for this assembly and put it into an

// IsolatedStoreFile object.

IsolatedStorageFile isoStore =IsolatedStorageFile.GetStore(IsolatedStorageScope.User | IsolatedStorageScope.Assembly, null, null);

// This code checks to see if the file already exists.

string[] fileNames = isoStore.GetFileNames("TestStore.txt");

foreach (string file in fileNames){

 if(file == "TestStore.txt"){

Console.WriteLine("The file already exists!");

Console.WriteLine("Type \"StoreAdm /REMOVE\" at the command line to delete all Isolated Storage for this user.");

// Exit the program.

return 0;

writeToFile(isoStore);

Console.WriteLine("The file \"TestStore.txt\" contains:");

// Call the readFromFile and write the returned string to the

//console.

Console.WriteLine(readFromFile(isoStore));

// Exit the program.

return 0;

 }// End of main.

 // This method writes "Hello Isolated Storage" to the file.

 private static void writeToFile(IsolatedStorageFile isoStore){

// Declare a new StreamWriter.

StreamWriter writer = null;

// Assign the writer to the store and the file TestStore.

writer = new StreamWriter(new IsolatedStorageFileStream("TestStore.txt", FileMode.CreateNew,isoStore));

// Have the writer write "Hello Isolated Storage" to the store.

writer.WriteLine("Hello Isolated Storage");

writer.Close();

Console.WriteLine("You have written to the file.");

 }// End of writeToFile.

 // This method reads the first line in the "TestStore.txt" file.

 public static String readFromFile(IsolatedStorageFile isoStore){

// This code opens the TestStore.txt file and reads the string.

StreamReader reader = new StreamReader(new IsolatedStorageFileStream("TestStore.txt", FileMode.Open,isoStore));

// Read a line from the file and add it to sb.

String sb = reader.ReadLine();

// Close the reader.

reader.Close();

// Return the string.

return sb.ToString();

 }// End of readFromFile.

刪除文件和目錄

您可以刪除獨立存儲文件中的目錄和文件。請記住，在存儲區中，文件名和目錄名是與操作系統相關的（在 Microsoft Windows 系統中通常不區分大小寫），并且是根據虛文件系統的根目錄具體而定的。
IsolatedStoreFile 類提供了兩種刪除目錄和文件的實例方法：DeleteDirectory 和 DeleteFile。如果嘗試刪除并不存在的文件和目錄，則會引發 IsolatedStorageFileException。如果名稱中包含有通配符，則 DeleteDirectory 會引發 IsolatedStorageFileException，而 DeleteFile 將引發 ArgumentException。
如果目錄中包含任何文件或子目錄，DeleteDirectory 將會失敗。在 DeletingFilesAndDirectories 示例的一部分中定義了一個方法，該方法刪除目錄中的所有內容，然后刪除目錄本身。同樣，您可以自己定義一個接受通配符的 DeleteFiles 方法，該方法可以這樣來實現：使用 GetFileNames 方法獲取所有匹配文件的列表，然后依次刪除每個文件。

DeletingFilesAndDirectories 示例

下面的代碼示例先創建若干個目錄和文件，然后將它們刪除。

 [C#]

using System;

using System.IO.IsolatedStorage;

using System.IO;

public class DeletingFilesDirectories{

 public static void Main(){

// Get a new isolated store for this user domain and assembly.

// Put the store into an isolatedStorageFile object.

IsolatedStorageFile isoStore =IsolatedStorageFile.GetStore(IsolatedStorageScope.User | IsolatedStorageScope.Domain | IsolatedStorageScope.Assembly, null, null);

Console.WriteLine("Creating Directories:");

// This code creates several different directories.

isoStore.CreateDirectory("TopLevelDirectory");

Console.WriteLine("TopLevelDirectory");

isoStore.CreateDirectory("TopLevelDirectory/SecondLevel");

Console.WriteLine("TopLevelDirectory/SecondLevel");

// This code creates two new directories, one inside the other.

isoStore.CreateDirectory("AnotherTopLevelDirectory/InsideDirectory");

Console.WriteLine("AnotherTopLevelDirectory/InsideDirectory");

Console.WriteLine();

// This code creates a few files and places them in the directories.

Console.WriteLine("Creating Files:");

// This file is placed in the root.

IsolatedStorageFileStream isoStream1 = new IsolatedStorageFileStream("InTheRoot.txt", FileMode.Create, isoStore);

Console.WriteLine("InTheRoot.txt");

isoStream1.Close();

// This file is placed in the InsideDirectory.

IsolatedStorageFileStream isoStream2 = new IsolatedStorageFileStream("AnotherTopLevelDirectory/InsideDirectory/HereIAm.txt", FileMode.Create, isoStore);

Console.WriteLine("AnotherTopLevelDirectory/InsideDirectory/HereIAm.txt");

Console.WriteLine();

isoStream2.Close();

Console.WriteLine("Deleting File:");

// This code deletes the HereIAm.txt file.

isoStore.DeleteFile("AnotherTopLevelDirectory/InsideDirectory/HereIAm.txt");

Console.WriteLine("AnotherTopLevelDirectory/InsideDirectory/HereIAm.txt");

Console.WriteLine();

Console.WriteLine("Deleting Directory:");

// This code deletes the InsideDirectory.

isoStore.DeleteDirectory("AnotherTopLevelDirectory/InsideDirectory/");

Console.WriteLine("AnotherTopLevelDirectory/InsideDirectory/");

Console.WriteLine();

 }// End of main.

總結

上面是VS.NET中.NET中IO的基本概念、示例代碼以及訪問文件系統的基礎方法和流程，大家可以多多實踐。有任何建議請MAIL我 paulni@citiz.net(paulni@citiz.net)。

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