Como: Ler e gravar arquivos no armazenamento isolado
Há várias maneiras de abrir um arquivo em um armazenamento usando a classe IsolatedStorageFileStream. Depois que um IsolatedStorageFileStream foi obtido, ele pode ser usado para obter um StreamReader ou StreamWriter. Com o StreamReader e o StreamWriter , você pode ler e gravar em um arquivo em um armazenamento como faria com qualquer outro arquivo. Para uma discussão mais ampla sobre leitura e gravação em um arquivo, consulte E/S de arquivo e de fluxo.
Exemplo de ReadingAndWritingToFiles
O exemplo de código a seguir obtém um armazenamento isolado, cria um arquivo chamado TestStore.txt, e grava "Hello isolado Storage" no arquivo. Em seguida, o código lê o arquivo e imprime os resultados para o console.
Imports System
Imports System.IO
Imports System.IO.IsolatedStorage
Public Class ReadingAndWritingToFiles
Public Shared Function Main() As Integer
' Get an isolated store for this assembly and put it into an
' IsolatedStoreFile object.
Dim isoStore As IsolatedStorageFile = IsolatedStorageFile.GetStore(IsolatedStorageScope.User Or
IsolatedStorageScope.Assembly, Nothing, Nothing)
' This code checks to see if the file already exists.
Dim fileNames() As String = isoStore.GetFileNames("TestStore.txt")
For Each file As String In fileNames
If file = "TestStore.txt" Then
Console.WriteLine("The file already exists!")
Console.Write("Type ""StoreAdm /REMOVE"" at the command line to delete all ")
Console.WriteLine("Isolated Storage for this user.")
' Exit the program.
Return 0
End If
Next
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 Function ' End of main.
' This method writes "Hello Isolated Storage" to the file.
Private Shared Sub writeToFile(isoStore As IsolatedStorageFile)
' Declare a new StreamWriter.
Dim writer As StreamWriter = Nothing
' 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 Sub ' End of writeToFile.
' This method reads the first line in the "TestStore.txt" file.
Private Shared Function readFromFile(isoStore As IsolatedStorageFile) As String
' This code opens the TestStore.txt file and reads the string.
Dim reader As New StreamReader(New IsolatedStorageFileStream(
"TestStore.txt", FileMode.Open, isoStore))
' Read a line from the file and add it to sb.
Dim sb As String = reader.ReadLine()
' Close the reader.
reader.Close()
' Return the string.
Return sb.ToString()
End Function ' End of readFromFile.
End Class
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.Write("Type \"StoreAdm /REMOVE\" at the command line to delete all ");
Console.WriteLine("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.
private 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.
}
using namespace System;
using namespace System::IO;
using namespace System::IO::IsolatedStorage;
public ref 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, (Type ^)nullptr, (Type ^)nullptr);
// This code checks to see if the file already exists.
array<String^>^ fileNames = isoStore->GetFileNames("TestStore.txt");
for each (String^ file in fileNames)
{
if (file == "TestStore.txt")
{
Console::WriteLine("The file already exists!");
Console::Write("Type \"StoreAdm /REMOVE\" at the command line to delete all ");
Console::WriteLine("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.
private:
// This method writes "Hello Isolated Storage" to the file.
static void writeToFile(IsolatedStorageFile^ isoStore)
{
// Declare a new StreamWriter.
StreamWriter^ writer = nullptr;
// Assign the writer to the store and the file TestStore.
writer = gcnew StreamWriter(gcnew 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.
static String^ readFromFile(IsolatedStorageFile^ isoStore)
{
// This code opens the TestStore.txt file and reads the string.
StreamReader^ reader = gcnew StreamReader(gcnew 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.
};
int main()
{
return ReadingAndWritingToFiles::Main();
}