FileInfo.CopyTo 方法

定义

将现有文件复制到新文件。Copies an existing file to a new file.

重载

CopyTo(String)

将现有文件复制到新文件,不允许覆盖现有文件。Copies an existing file to a new file, disallowing the overwriting of an existing file.

CopyTo(String, Boolean)

将现有文件复制到新文件,允许覆盖现有文件。Copies an existing file to a new file, allowing the overwriting of an existing file.

CopyTo(String)

将现有文件复制到新文件,不允许覆盖现有文件。Copies an existing file to a new file, disallowing the overwriting of an existing file.

public:
 System::IO::FileInfo ^ CopyTo(System::String ^ destFileName);
public System.IO.FileInfo CopyTo (string destFileName);
member this.CopyTo : string -> System.IO.FileInfo
Public Function CopyTo (destFileName As String) As FileInfo

参数

destFileName
String

要复制到的新文件的名称。The name of the new file to copy to.

返回

带有完全限定路径的新文件。A new file with a fully qualified path.

异常

destFileName 为空,仅包含空格,或包含无效字符。destFileName is empty, contains only white spaces, or contains invalid characters.

出现错误,或目标文件已存在。An error occurs, or the destination file already exists.

调用方没有所要求的权限。The caller does not have the required permission.

destFileNamenulldestFileName is null.

传入一个目录路径或此文件将被移至其他驱动器。A directory path is passed in, or the file is being moved to a different drive.

destFileName 中指定的此目录不存在。The directory specified in destFileName does not exist.

指定的路径和/或文件名超过了系统定义的最大长度。The specified path, file name, or both exceed the system-defined maximum length.

destFileName 在其字符串中包含冒号 (:) ,但并未指定卷。destFileName contains a colon (:) within the string but does not specify the volume.

示例

下面的示例演示CopyTo方法的两个重载。The following example demonstrates both overloads of the CopyTo method.

using namespace System;
using namespace System::IO;

int main()
{
   String^ path = "c:\\MyTest.txt";
   String^ path2 = "c:\\MyTest.txttemp";
   FileInfo^ fi1 = gcnew FileInfo( path );
   FileInfo^ fi2 = gcnew FileInfo( path2 );
   try
   {
      // Create the file and clean up handles.
      FileStream^ fs = fi1->Create();
      if ( fs )
         delete (IDisposable^)fs;
      
      //Ensure that the target does not exist.
      fi2->Delete();
      
      //Copy the file.
      fi1->CopyTo( path2 );
      Console::WriteLine( "{0} was copied to {1}.", path, path2 );
      
      //Try to copy it again, which should succeed.
      fi1->CopyTo( path2, true );
      Console::WriteLine( "The second Copy operation succeeded, which is expected." );
   }
   catch ( Exception^ ) 
   {
      Console::WriteLine( "Double copying was not allowed, which is not expected." );
   }
}
//This code produces output similar to the following; 
//results may vary based on the computer/file structure/etc.:
//
//The second Copy operation succeeded, which is expected.
using System;
using System.IO;

class Test
{

    public static void Main()
    {
        string path = @"c:\SoureFile.txt";
        string path2 = @"c:\NewFile.txt";
        FileInfo fi1 = new FileInfo(path);
        FileInfo fi2 = new FileInfo(path2);

        try
        {
            // Create the source file.
            using (FileStream fs = fi1.Create()) { }

            //Ensure that the target file does not exist.
            if (File.Exists(path2))
            {
                fi2.Delete();
            }

            //Copy the file.f
            fi1.CopyTo(path2);
            Console.WriteLine("{0} was copied to {1}.", path, path2);
        }
        catch (IOException ioex)
        {
            Console.WriteLine(ioex.Message);
        }
    }
}
Imports System.IO

Public Class Test

    Public Shared Sub Main()
        'Specify the directories you want to manipulate.
        Dim path As String = "c:\SourceFile.txt"
        Dim path2 As String = "c:\NewFile.txt"
        Dim fi As FileInfo = New FileInfo(path)
        Dim fi2 As FileInfo = New FileInfo(path2)

        Try
            Using fs As FileStream = fi.Create()
            End Using

            'Ensure that the target does not exist.
            If File.Exists(path2) Then
                fi2.Delete()
            End If
            
            'Copy the file.
            fi.CopyTo(path2)
            Console.WriteLine("{0} was copied to {1}.", path, path2)

        Catch ioex As IOException
            Console.WriteLine(ioex.Message)
        End Try
    End Sub
End Class

下面的示例演示如何将一个文件复制到另一个文件, 如果目标文件已存在, 则会引发异常。The following example demonstrates copying one file to another file, throwing an exception if the destination file already exists.

using namespace System;
using namespace System::IO;
int main()
{
   try
   {
      
      // Create a reference to a file, which might or might not exist.
      // If it does not exist, it is not yet created.
      FileInfo^ fi = gcnew FileInfo( "temp.txt" );
      
      // Create a writer, ready to add entries to the file.
      StreamWriter^ sw = fi->AppendText();
      sw->WriteLine( "Add as many lines as you like..." );
      sw->WriteLine( "Add another line to the output..." );
      sw->Flush();
      sw->Close();
      
      // Get the information out of the file and display it.
      StreamReader^ sr = gcnew StreamReader( fi->OpenRead() );
      Console::WriteLine( "This is the information in the first file:" );
      while ( sr->Peek() != -1 )
            Console::WriteLine( sr->ReadLine() );
      
      // Copy this file to another file. The file will not be overwritten if it already exists.
      FileInfo^ newfi = fi->CopyTo( "newTemp.txt" );
      
      // Get the information out of the new file and display it.* sr = new StreamReader(newfi->OpenRead());
      Console::WriteLine( "{0}This is the information in the second file:", Environment::NewLine );
      while ( sr->Peek() != -1 )
            Console::WriteLine( sr->ReadLine() );
   }
   catch ( Exception^ e ) 
   {
      Console::WriteLine( e->Message );
   }

}
//This code produces output similar to the following; 
//results may vary based on the computer/file structure/etc.:
//
//This is the information in the first file:
//Add as many lines as you like...
//Add another line to the output...
//
//This is the information in the second file:

using System;
using System.IO;

public class CopyToTest 
{
    public static void Main() 
    {
        try
        {
            // Create a reference to a file, which might or might not exist.
            // If it does not exist, it is not yet created.
            FileInfo fi = new FileInfo("temp.txt");
            // Create a writer, ready to add entries to the file.
            StreamWriter sw = fi.AppendText();
            sw.WriteLine("Add as many lines as you like...");
            sw.WriteLine("Add another line to the output...");
            sw.Flush();
            sw.Close();
            // Get the information out of the file and display it.
            StreamReader sr = new StreamReader(fi.OpenRead());
            Console.WriteLine("This is the information in the first file:");
            while (sr.Peek() != -1)
                Console.WriteLine(sr.ReadLine());
            // Copy this file to another file. The file will not be overwritten if it already exists.
            FileInfo newfi = fi.CopyTo("newTemp.txt");
            // Get the information out of the new file and display it.
            sr = new StreamReader(newfi.OpenRead());
            Console.WriteLine("{0}This is the information in the second file:", Environment.NewLine);
            while (sr.Peek() != -1)
                Console.WriteLine(sr.ReadLine());
        }
        catch(Exception e)
        {
            Console.WriteLine(e.Message);
        }
    }
}
//This code produces output similar to the following; 
//results may vary based on the computer/file structure/etc.:
//
//This is the information in the first file:
//Add as many lines as you like...
//Add another line to the output...

//This is the information in the second file:
//Add as many lines as you like...
//Add another line to the output...
Imports System.IO

Public Class CopyToTest
    Public Shared Sub Main()
        Try
            ' Create a reference to a file, which might or might not exist.
            ' If it does not exist, it is not yet created.
            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("Add as many lines as you like...")
            sw.WriteLine("Add another line to the output...")
            sw.Flush()
            sw.Close()
            ' Get the information out of the file and display it.
            Dim sr As New StreamReader(fi.OpenRead())
            Console.WriteLine("This is the information in the first file:")
            While sr.Peek() <> -1
                Console.WriteLine(sr.ReadLine())
            End While
            ' Copy this file to another file.
            Dim newfi As FileInfo = fi.CopyTo("newTemp.txt")
            ' Get the information out of the new file and display it.
            sr = New StreamReader(newfi.OpenRead())
            Console.WriteLine("{0}This is the information in the second file:", Environment.NewLine)
            While sr.Peek() <> -1
                Console.WriteLine(sr.ReadLine())
            End While
        Catch e As Exception
            Console.WriteLine(e.Message)
        End Try
    End Sub
End Class
'This code produces output similar to the following; 
'results may vary based on the computer/file structure/etc.:
'
'This is the information in the first file:
'Add as many lines as you like...
'Add another line to the output...
'
'This is the information in the second file:
'Add as many lines as you like...
'Add another line to the output...

注解

CopyTo(String, Boolean)使用方法可允许覆盖现有文件。Use the CopyTo(String, Boolean) method to allow overwriting of an existing file.

注意

请尽可能避免使用带有此方法的短文件名 (例如 XXXXXX ~ 1)。Whenever possible, avoid using short file names (such as XXXXXX~1.XXX) with this method. 如果两个文件具有等效的短文件名, 则此方法可能会失败并引发异常, 并/或导致意外行为If two files have equivalent short file names then this method may fail and raise an exception and/or result in undesirable behavior

安全性

FileIOPermission
用于读取和写入文件。for reading and writing files. 关联的枚举Read:WriteAssociated enumerations: Read, Write

另请参阅

CopyTo(String, Boolean)

将现有文件复制到新文件,允许覆盖现有文件。Copies an existing file to a new file, allowing the overwriting of an existing file.

public:
 System::IO::FileInfo ^ CopyTo(System::String ^ destFileName, bool overwrite);
public System.IO.FileInfo CopyTo (string destFileName, bool overwrite);
member this.CopyTo : string * bool -> System.IO.FileInfo
Public Function CopyTo (destFileName As String, overwrite As Boolean) As FileInfo

参数

destFileName
String

要复制到的新文件的名称。The name of the new file to copy to.

overwrite
Boolean

如果允许覆盖现有文件,则为 true;否则为 falsetrue to allow an existing file to be overwritten; otherwise, false.

返回

为新文件;如果 overwritetrue,则为现有文件的覆盖。A new file, or an overwrite of an existing file if overwrite is true. 如果文件存在且 overwritefalse,则引发 IOExceptionIf the file exists and overwrite is false, an IOException is thrown.

异常

destFileName 为空,仅包含空格,或包含无效字符。destFileName is empty, contains only white spaces, or contains invalid characters.

出现错误,或目标文件已存在,且 overwritefalseAn error occurs, or the destination file already exists and overwrite is false.

调用方没有所要求的权限。The caller does not have the required permission.

destFileNamenulldestFileName is null.

destFileName 中指定的此目录不存在。The directory specified in destFileName does not exist.

传入一个目录路径或此文件将被移至其他驱动器。A directory path is passed in, or the file is being moved to a different drive.

指定的路径和/或文件名超过了系统定义的最大长度。The specified path, file name, or both exceed the system-defined maximum length.

destFileName 在字符串中间包含一个冒号 (:)。destFileName contains a colon (:) in the middle of the string.

示例

下面的示例演示CopyTo方法的两个重载。The following example demonstrates both overloads of the CopyTo method.

using namespace System;
using namespace System::IO;

int main()
{
   String^ path = "c:\\MyTest.txt";
   String^ path2 = "c:\\MyTest.txttemp";
   FileInfo^ fi1 = gcnew FileInfo( path );
   FileInfo^ fi2 = gcnew FileInfo( path2 );
   try
   {
      // Create the file and clean up handles.
      FileStream^ fs = fi1->Create();
      if ( fs )
         delete (IDisposable^)fs;
      
      //Ensure that the target does not exist.
      fi2->Delete();
      
      //Copy the file.
      fi1->CopyTo( path2 );
      Console::WriteLine( "{0} was copied to {1}.", path, path2 );
      
      //Try to copy it again, which should succeed.
      fi1->CopyTo( path2, true );
      Console::WriteLine( "The second Copy operation succeeded, which is expected." );
   }
   catch ( Exception^ ) 
   {
      Console::WriteLine( "Double copying was not allowed, which is not expected." );
   }
}
//This code produces output similar to the following; 
//results may vary based on the computer/file structure/etc.:
//
//The second Copy operation succeeded, which is expected.
using System;
using System.IO;

class Test
{

    public static void Main()
    {
        string path = @"c:\SoureFile.txt";
        string path2 = @"c:\NewFile.txt";
        FileInfo fi1 = new FileInfo(path);
        FileInfo fi2 = new FileInfo(path2);

        try
        {
            // Create the source file.
            using (FileStream fs = fi1.Create()) { }

            //Ensure that the target file does not exist.
            if (File.Exists(path2))
            {
                fi2.Delete();
            }

            //Copy the file.f
            fi1.CopyTo(path2);
            Console.WriteLine("{0} was copied to {1}.", path, path2);
        }
        catch (IOException ioex)
        {
            Console.WriteLine(ioex.Message);
        }
    }
}
Imports System.IO

Public Class Test

    Public Shared Sub Main()
        'Specify the directories you want to manipulate.
        Dim path As String = "c:\SourceFile.txt"
        Dim path2 As String = "c:\NewFile.txt"
        Dim fi As FileInfo = New FileInfo(path)
        Dim fi2 As FileInfo = New FileInfo(path2)

        Try
            Using fs As FileStream = fi.Create()
            End Using

            'Ensure that the target does not exist.
            If File.Exists(path2) Then
                fi2.Delete()
            End If
            
            'Copy the file.
            fi.CopyTo(path2)
            Console.WriteLine("{0} was copied to {1}.", path, path2)

        Catch ioex As IOException
            Console.WriteLine(ioex.Message)
        End Try
    End Sub
End Class

下面的示例演示如何将一个文件复制到另一个文件, 并指定是否覆盖已存在的文件。The following example demonstrates copying one file to another file, specifying whether to overwrite a file that already exists.

using namespace System;
using namespace System::IO;
int main()
{
   
   // Create a reference to a file, which might or might not exist.
   // If it does not exist, it is not yet created.
   FileInfo^ fi = gcnew FileInfo( "temp.txt" );
   
   // Create a writer, ready to add entries to the file.
   StreamWriter^ sw = fi->AppendText();
   sw->WriteLine( "Add as many lines as you like..." );
   sw->WriteLine( "Add another line to the output..." );
   sw->Flush();
   sw->Close();
   
   // Get the information out of the file and display it.
   StreamReader^ sr = gcnew StreamReader( fi->OpenRead() );
   Console::WriteLine( "This is the information in the first file:" );
   while ( sr->Peek() != -1 )
      Console::WriteLine( sr->ReadLine() );

   
   // Copy this file to another file. The true parameter specifies
   // that the file will be overwritten if it already exists.
   FileInfo^ newfi = fi->CopyTo( "newTemp.txt", true );
   
   // Get the information out of the new file and display it.* sr = new StreamReader( newfi->OpenRead() );
   Console::WriteLine( "{0}This is the information in the second file:", Environment::NewLine );
   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 the information in the first file:
//Add as many lines as you like...
//Add another line to the output...
//This is the information in the second file:
//
using System;
using System.IO;

public class CopyToTest 
{
    public static void Main() 
    {
        // Create a reference to a file, which might or might not exist.
        // If it does not exist, it is not yet created.
        FileInfo fi = new FileInfo("temp.txt");
        // Create a writer, ready to add entries to the file.
        StreamWriter sw = fi.AppendText();
        sw.WriteLine("Add as many lines as you like...");
        sw.WriteLine("Add another line to the output...");
        sw.Flush();
        sw.Close();
        // Get the information out of the file and display it.
        StreamReader sr = new StreamReader( fi.OpenRead() );
        Console.WriteLine("This is the information in the first file:");
        while (sr.Peek() != -1)
            Console.WriteLine( sr.ReadLine() );
        // Copy this file to another file. The true parameter specifies
        // that the file will be overwritten if it already exists.
        FileInfo newfi = fi.CopyTo("newTemp.txt", true);
        // Get the information out of the new file and display it.
        sr = new StreamReader( newfi.OpenRead() );
        Console.WriteLine("{0}This is the information in the second file:", Environment.NewLine);
        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 the information in the first file:
//Add as many lines as you like...
//Add another line to the output...
//Add as many lines as you like...
//Add another line to the output...

//This is the information in the second file:
//Add as many lines as you like...
//Add another line to the output...
//Add as many lines as you like...
//Add another line to the output...

Imports System.IO

Public Class CopyToTest
    Public Shared Sub Main()
        ' Create a reference to a file, which might or might not exist.
        ' If it does not exist, it is not yet created.
        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("Add as many lines as you like...")
        sw.WriteLine("Add another line to the output...")
        sw.Flush()
        sw.Close()
        ' Get the information out of the file and display it.
        Dim sr As New StreamReader(fi.OpenRead())
        Console.WriteLine("This is the information in the first file:")
        While sr.Peek() <> -1
            Console.WriteLine(sr.ReadLine())
        End While
        ' Copy this file to another file. The true parameter specifies 
        ' that the file will be overwritten if it already exists.
        Dim newfi As FileInfo = fi.CopyTo("newTemp.txt", True)
        ' Get the information out of the new file and display it.
        sr = New StreamReader(newfi.OpenRead())
        Console.WriteLine("{0}This is the information in the second file:", Environment.NewLine)
        While sr.Peek() <> -1
            Console.WriteLine(sr.ReadLine())
        End While
    End Sub
End Class
'This code produces output similar to the following; 
'results may vary based on the computer/file structure/etc.:
'
'This is the information in the first file:
'Add as many lines as you like...
'Add another line to the output...
'
'This is the information in the second file:
'Add as many lines as you like...
'Add another line to the output...
'

注解

使用此方法可允许或禁止覆盖现有文件。Use this method to allow or prevent overwriting of an existing file. 默认情况CopyTo(String)下, 使用方法来防止覆盖现有文件。Use the CopyTo(String) method to prevent overwriting of an existing file by default.

注意

请尽可能避免使用带有此方法的短文件名 (例如 XXXXXX ~ 1)。Whenever possible, avoid using short file names (such as XXXXXX~1.XXX) with this method. 如果两个文件具有等效的短文件名, 则此方法可能会失败并引发异常, 并/或导致意外行为If two files have equivalent short file names then this method may fail and raise an exception and/or result in undesirable behavior

安全性

FileIOPermission
用于读取和写入文件。for reading and writing files. 关联的枚举Read:WriteAssociated enumerations: Read, Write

另请参阅

适用于