File.Copy 方法

定義

命名空間:: System.IO

組件:: mscorlib.dll, System.IO.FileSystem.dll

組件:: netstandard.dll, System.Runtime.dll

組件:: netstandard.dll, System.IO.FileSystem.dll

組件:: netstandard.dll, System.IO.FileSystem.dll, System.Runtime.dll

組件:: System.IO.FileSystem.dll

組件:: mscorlib.dll

組件:: netstandard.dll

重要

部分資訊涉及發行前產品，在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊，不做任何明確或隱含的瑕疵擔保。

將現有的檔案複製到新的檔案。

多載

名稱	Description
Copy(String, String)	將現有的檔案複製到新的檔案。不允許覆寫同名檔案。
Copy(String, String, Boolean)	將現有的檔案複製到新的檔案。允許覆寫同名檔案。

Copy(String, String)

來源:: File.cs

來源:: File.cs

來源:: File.cs

來源:: File.cs

來源:: File.cs

將現有的檔案複製到新的檔案。不允許覆寫同名檔案。

public:
 static void Copy(System::String ^ sourceFileName, System::String ^ destFileName);

public static void Copy(string sourceFileName, string destFileName);

static member Copy : string * string -> unit

Public Shared Sub Copy (sourceFileName As String, destFileName As String)

參數

sourceFileName: String

要複製的檔案。

destFileName: String

目的地檔案的名稱。這不能是目錄或現有檔案。

例外狀況

UnauthorizedAccessException

來電者沒有所需的權限。

ArgumentException

sourceFileName 或 destFileName 為零長度字串、僅有空白，或包含一個或多個無效字元。你可以用這個 GetInvalidPathChars() 方法查詢無效字元。

-或-

sourceFileName 或 destFileName 指定目錄。

ArgumentNullException

sourceFileName 或 destFileName 為 null。

PathTooLongException

指定的路徑、檔名或兩者都超過系統定義的最大長度。

DirectoryNotFoundException

或 sourceFileName 中指定的destFileName路徑無效（例如，該路徑位於未映射的磁碟機上）。

FileNotFoundException

sourceFileName 未被找到。

IOException

destFileName 存在。

-或-

發生了 I/O 錯誤。

NotSupportedException

sourceFileName 或 destFileName 格式無效。

範例

以下範例將檔案複製到 C：\archives\2008 備份資料夾。它使用該方法的 Copy 兩個過載方式如下：

它首先利用 File.Copy(String, String) 方法過載來複製文字（.txt）檔案。程式碼顯示這種過載不允許覆蓋已複製的檔案。
接著它會利用 File.Copy(String, String, Boolean) 方法超載來複製圖片（.jpg 檔案）。程式碼顯示這種過載確實允許覆蓋已複製的檔案。

string sourceDir = @"c:\current";
string backupDir = @"c:\archives\2008";

try
{
    string[] picList = Directory.GetFiles(sourceDir, "*.jpg");
    string[] txtList = Directory.GetFiles(sourceDir, "*.txt");

    // Copy picture files.
    foreach (string f in picList)
    {
        // Remove path from the file name.
        string fName = f.Substring(sourceDir.Length + 1);

        // Use the Path.Combine method to safely append the file name to the path.
        // Will overwrite if the destination file already exists.
        File.Copy(Path.Combine(sourceDir, fName), Path.Combine(backupDir, fName), true);
    }

    // Copy text files.
    foreach (string f in txtList)
    {

        // Remove path from the file name.
        string fName = f.Substring(sourceDir.Length + 1);

        try
        {
            // Will not overwrite if the destination file already exists.
            File.Copy(Path.Combine(sourceDir, fName), Path.Combine(backupDir, fName));
        }

        // Catch exception if the file was already copied.
        catch (IOException copyError)
        {
            Console.WriteLine(copyError.Message);
        }
    }

    // Delete source files that were copied.
    foreach (string f in txtList)
    {
        File.Delete(f);
    }
    foreach (string f in picList)
    {
        File.Delete(f);
    }
}

catch (DirectoryNotFoundException dirNotFound)
{
    Console.WriteLine(dirNotFound.Message);
}

let sourceDir = @"c:\current"
let backupDir = @"c:\archives\2008"

try
    let picList = Directory.GetFiles(sourceDir, "*.jpg")
    let txtList = Directory.GetFiles(sourceDir, "*.txt")

    // Copy picture files.
    for f in picList do
        // Remove path from the file name.
        let fName = f.Substring(sourceDir.Length + 1)

        // Use the Path.Combine method to safely append the file name to the path.
        // Will overwrite if the destination file already exists.
        File.Copy(Path.Combine(sourceDir, fName), Path.Combine(backupDir, fName), true)

    // Copy text files.
    for f in txtList do
        // Remove path from the file name.
        let fName = f.Substring(sourceDir.Length + 1)

        try
            // Will not overwrite if the destination file already exists.
            File.Copy(Path.Combine(sourceDir, fName), Path.Combine(backupDir, fName))

        // Catch exception if the file was already copied.
        with
        | :? IOException as copyError -> printfn $"{copyError.Message}"

    // Delete source files that were copied.
    for f in txtList do
        File.Delete f

    for f in picList do
        File.Delete f

// Catch exception if the file was already copied.
with
| :? DirectoryNotFoundException as dirNotFound -> printfn $"{dirNotFound.Message}"

Dim sourceDir As String = "c:\current"
Dim backupDir As String = "c:\archives\2008"

Try
    Dim picList As String() = Directory.GetFiles(sourceDir, "*.jpg")
    Dim txtList As String() = Directory.GetFiles(sourceDir, "*.txt")

    ' Copy picture files.
    For Each f As String In picList
        'Remove path from the file name.
        Dim fName As String = f.Substring(sourceDir.Length + 1)

        ' Use the Path.Combine method to safely append the file name to the path.
        ' Will overwrite if the destination file already exists.
        File.Copy(Path.Combine(sourceDir, fName), Path.Combine(backupDir, fName), True)
    Next

    ' Copy text files.
    For Each f As String In txtList

        'Remove path from the file name.
        Dim fName As String = f.Substring(sourceDir.Length + 1)

        Try
            ' Will not overwrite if the destination file already exists.
            File.Copy(Path.Combine(sourceDir, fName), Path.Combine(backupDir, fName))

            ' Catch exception if the file was already copied.
        Catch copyError As IOException
            Console.WriteLine(copyError.Message)
        End Try
    Next

    For Each f As String In txtList
        File.Delete(f)
    Next

    For Each f As String In picList
        File.Delete(f)
    Next

Catch dirNotFound As DirectoryNotFoundException
    Console.WriteLine(dirNotFound.Message)
End Try

備註

此方法等同 Copy(String, String, Boolean) 於參數 overwrite 設為 false的方法過載。

和sourceFileName參數destFileName可指定相對或絕對路徑資訊。相對路徑資訊會被解讀為相對於目前工作目錄的相對於。要取得目前的工作目錄，請參閱該方法。Directory.GetCurrentDirectory 此方法不支援參數中的萬用字元。

原始檔案的屬性會保留在複製的檔案中。

另請參閱

適用於

Copy(String, String, Boolean)

來源:: File.cs

來源:: File.cs

來源:: File.cs

來源:: File.cs

來源:: File.cs

將現有的檔案複製到新的檔案。允許覆寫同名檔案。

public:
 static void Copy(System::String ^ sourceFileName, System::String ^ destFileName, bool overwrite);

public static void Copy(string sourceFileName, string destFileName, bool overwrite);

static member Copy : string * string * bool -> unit

Public Shared Sub Copy (sourceFileName As String, destFileName As String, overwrite As Boolean)

參數

sourceFileName: String

要複製的檔案。

destFileName: String

目的地檔案的名稱。這不可能是目錄。

overwrite: Boolean

true如果目標檔案已經存在，是否應該被替換;否則，。 false