FileInfo(String) FileInfo(String) FileInfo(String) FileInfo(String) Constructor

定義

ファイル パスのラッパーとして機能する、FileInfo クラスの新しいインスタンスを初期化します。Initializes a new instance of the FileInfo class, which acts as a wrapper for a file path.

public:
 FileInfo(System::String ^ fileName);
public FileInfo (string fileName);
new System.IO.FileInfo : string -> System.IO.FileInfo
Public Sub New (fileName As String)

パラメーター

fileName
String String String String

新しいファイルの完全修飾名または相対ファイル名。The fully qualified name of the new file, or the relative file name. パスの末尾がディレクトリの区切り記号にならないようにしてください。Do not end the path with the directory separator character.

例外

呼び出し元に、必要なアクセス許可がありません。The caller does not have the required permission.

ファイル名は空で、空白のみで構成されているか、正しくない文字を含んでいます。The file name is empty, contains only white spaces, or contains invalid characters.

fileName へのアクセスが拒否されましたAccess to fileName is denied.

指定したパス、ファイル名、またはその両方がシステム定義の最大長を超えています。The specified path, file name, or both exceed the system-defined maximum length.

fileName の文字列の途中にコロン (:) が含まれています。fileName contains a colon (:) in the middle of the string.

次の例では、このコンス トラクターを使用して、からの読み取りに書き込まれた、コピー、および削除する 2 つのファイルを作成します。The following example uses this constructor to create two files, which are then written to, read from, copied, and deleted.

using namespace System;
using namespace System::IO;

int main()
{
   String^ path = "c:\\MyTest.txt";
   FileInfo^ fi1 = gcnew FileInfo( path );
   if (  !fi1->Exists )
   {
      //Create a file to write to.
      StreamWriter^ sw = fi1->CreateText();
      try
      {
         sw->WriteLine( "Hello" );
         sw->WriteLine( "And" );
         sw->WriteLine( "Welcome" );
      }
      finally
      {
         if ( sw )
            delete (IDisposable^)sw;
      }
   }

   //Open the file to read from.
   StreamReader^ sr = fi1->OpenText();
   try
   {
      String^ s = "";
      while ( s = sr->ReadLine() )
      {
         Console::WriteLine( s );
      }
   }
   finally
   {
      if ( sr )
         delete (IDisposable^)sr;
   }

   try
   {
      String^ path2 = String::Concat( path, "temp" );
      FileInfo^ fi2 = gcnew FileInfo( path2 );
      
      //Ensure that the target does not exist.
      fi2->Delete();
      
      //Copy the file.
      fi1->CopyTo( path2 );
      Console::WriteLine( "{0} was copied to {1}.", path, path2 );
      
      //Delete the newly created file.
      fi2->Delete();
      Console::WriteLine( "{0} was successfully deleted.", path2 );
   }
   catch ( Exception^ e ) 
   {
      Console::WriteLine( "The process failed: {0}", e );
   }
}

//This code produces output similar to the following; 
//results may vary based on the computer/file structure/etc.:
//
//Hello
//And
//Welcome
//c:\MyTest.txt was copied to c:\MyTest.txttemp.
//c:\MyTest.txttemp was successfully deleted.
using System;
using System.IO;

class Test 
{
	
    public static void Main() 
    {
        string path = @"c:\temp\MyTest.txt";
        FileInfo fi1 = new FileInfo(path);

        if (!fi1.Exists) 
        {
            //Create a file to write to.
            using (StreamWriter sw = fi1.CreateText()) 
            {
                sw.WriteLine("Hello");
                sw.WriteLine("And");
                sw.WriteLine("Welcome");
            }	
        }

        //Open the file to read from.
        using (StreamReader sr = fi1.OpenText()) 
        {
            string s = "";
            while ((s = sr.ReadLine()) != null) 
            {
                Console.WriteLine(s);
            }
        }

        try 
        {
            string path2 = path + "temp";
            FileInfo fi2 = new FileInfo(path2);

            //Ensure that the target does not exist.
            fi2.Delete();

            //Copy the file.
            fi1.CopyTo(path2);
            Console.WriteLine("{0} was copied to {1}.", path, path2);

            //Delete the newly created file.
            fi2.Delete();
            Console.WriteLine("{0} was successfully deleted.", path2);

        } 
        catch (Exception e) 
        {
            Console.WriteLine("The process failed: {0}", e.ToString());
        }
    }
}
//This code produces output similar to the following; 
//results may vary based on the computer/file structure/etc.:
//
//Hello
//And
//Welcome
//c:\MyTest.txt was copied to c:\MyTest.txttemp.
//c:\MyTest.txttemp was successfully deleted.
Imports System
Imports System.IO

Class Test

    Public Shared Sub Main()
        Dim path As String = "c:\temp\MyTest.txt"
        Dim fi1 As FileInfo = New FileInfo(path)

        If fi1.Exists = False Then
            'Create a file to write to.
            Dim sw As StreamWriter = fi1.CreateText()
            sw.WriteLine("Hello")
            sw.WriteLine("And")
            sw.WriteLine("Welcome")
            sw.Flush()
            sw.Close()
        End If

        'Open the file to read from.
        Dim sr As StreamReader = fi1.OpenText()

        Do While sr.Peek() >= 0
            Console.WriteLine(sr.ReadLine())
        Loop

        Try
            Dim path2 As String = path + "temp"
            Dim fi2 As FileInfo = New FileInfo(path2)

            'Ensure that the target does not exist.
            fi2.Delete()

            'Copy the file.
            fi1.CopyTo(path2)
            Console.WriteLine("{0} was copied to {1}.", path, path2)

            'Delete the newly created file.
            fi2.Delete()
            Console.WriteLine("{0} was successfully deleted.", path2)

        Catch e As Exception
            Console.WriteLine("The process failed: {0}", e.ToString())
        End Try
    End Sub
End Class
'This code produces output similar to the following; 
'results may vary based on the computer/file structure/etc.:
'
'Hello
'And
'Welcome
'c:\MyTest.txt was copied to c:\MyTest.txttemp.
'c:\MyTest.txttemp was successfully deleted.

次の例は、既存のファイルを開きますまたはファイルを作成します化し、ファイルにテキストを追加します。 結果が表示されます。The following example opens an existing file or creates a file, appends text to the file, and displays the results.

using namespace System;
using namespace System::IO;
int main()
{
   
   // Open an existing file, or create a new one.
   FileInfo^ fi = gcnew FileInfo( "temp.txt" );
   
   // Create a writer, ready to add entries to the file.
   StreamWriter^ sw = fi->AppendText();
   sw->WriteLine( "This is a new entry to add to the file" );
   sw->WriteLine( "This is yet another line to add..." );
   sw->Flush();
   sw->Close();
   
   // Get the information out of the file and display it.
   StreamReader^ sr = gcnew StreamReader( fi->OpenRead() );
   while ( sr->Peek() != -1 )
      Console::WriteLine( sr->ReadLine() );
}
//This code produces output similar to the following; 
//results may vary based on the computer/file structure/etc.:
//
//This is a new entry to add to the file
//This is yet another line to add...
using System;
using System.IO;

public class FileInfoMainTest 
{
    public static void Main() 
    {
        // Open an existing file, or create a new one.
        FileInfo fi = new FileInfo("temp.txt");
        // Create a writer, ready to add entries to the file.
        StreamWriter sw = fi.AppendText();
        sw.WriteLine("This is a new entry to add to the file");
        sw.WriteLine("This is yet another line to add...");
        sw.Flush();
        sw.Close();
        // Get the information out of the file and display it.
        StreamReader sr = new StreamReader( fi.OpenRead() );
        while (sr.Peek() != -1)
            Console.WriteLine( sr.ReadLine() );
    }
}
//This code produces output similar to the following; 
//results may vary based on the computer/file structure/etc.:
//
//Add as many lines as you like...
//Add another line to the output...
//This is a new entry to add to the file
//This is yet another line to add...
Imports System
Imports System.IO

Public Class FileInfoMainTest

    Public Shared Sub Main()
        ' Open an existing file, or create a new one.
        Dim fi As New FileInfo("temp.txt")
        ' Create a writer, ready to add entries to the file.
        Dim sw As StreamWriter = fi.AppendText()
        sw.WriteLine("This is a new entry to add to the file")
        sw.WriteLine("This is yet another line to add...")
        sw.Flush()
        sw.Close()
        Dim sr As New StreamReader(fi.OpenRead())
        ' Get the information out of the file and display it.
        While sr.Peek() <> -1
            Console.WriteLine(sr.ReadLine())
        End While
    End Sub 'Main
End Class 'FileInfoMainTest
'This code produces output similar to the following; 
'results may vary based on the computer/file structure/etc.:
'
'This is a new entry to add to the file
'This is yet another line to add...

注釈

完全修飾名または相対ファイル名のいずれかを指定できますが、セキュリティ チェックが完全修飾名を取得します。You can specify either the fully qualified or the relative file name, but the security check gets the fully qualified name.

セキュリティ

FileIOPermission
ファイルの読み取り用for reading files. 関連付けられた列挙体。 ReadAssociated enumeration: Read

適用対象

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