如何：從剪貼簿擷取資料

發行項
10/18/2024

Clipboard 類別提供可用來與 Windows 作業系統剪貼簿功能互動的方法。許多應用程式會使用剪貼簿作為資料的暫時存放庫。例如，文字處理器會在剪下和貼上作業期間使用剪貼簿。剪貼簿也可用來將資訊從一個應用程式傳輸至另一個應用程式。

有些應用程式可用多種格式將資料儲存在剪貼簿上，以增加其他可使用該資料的應用程式數目。剪貼簿格式是識別格式的字串。使用已識別格式的應用程式可以擷取剪貼簿上相關聯的資料。 DataFormats 類別會提供預先定義的格式名稱以供使用。您也可以使用自己的格式名稱，或使用物件的類型作為其格式。如需將資料新增至剪貼簿的相關資訊，請參閱操作說明：將資料新增至剪貼簿。

若要確認剪貼簿中是否包含特定格式的資料，請使用其中一個 ContainsFormat 方法或 GetData 方法。若要從剪貼簿中擷取資料，請使用其中一個 GetFormat 方法或 GetData 方法。這些都是 .NET Framework 2.0 中的新方法。

若要使用早於 .NET Framework 2.0 的版本從剪貼簿中存取資料，請使用 Clipboard.GetDataObject 方法，並呼叫傳回的 IDataObject 的方法。例如，若要確認特定格式在傳回的物件中是否適用，請呼叫 GetDataPresent 方法。

注意

所有以 Windows 為基礎的應用程式都會共用系統剪貼簿。因此，當您切換到另一個應用程式時，內容可能會改變。

Clipboard 類別只能在設定為單一執行緒 Apartment (STA) 模式的執行緒中使用。若要使用此類別，請確定您的 Main 方法已標示為 STAThreadAttribute 屬性。

以單一通用格式從剪貼簿中擷取資料

使用 GetAudioStream、GetFileDropList、GetImage 或 GetText 方法。或者，請先使用對應的 ContainsFormat 方法，確認資料是否適用特定格式。這些方法僅適用於 .NET Framework 2.0。

// Demonstrates SetAudio, ContainsAudio, and GetAudioStream.
public System.IO.Stream SwapClipboardAudio(
    System.IO.Stream replacementAudioStream)
{
    System.IO.Stream returnAudioStream = null;
    if (Clipboard.ContainsAudio())
    {
        returnAudioStream = Clipboard.GetAudioStream();
        Clipboard.SetAudio(replacementAudioStream);
    }
    return returnAudioStream;
}

// Demonstrates SetFileDropList, ContainsFileDroList, and GetFileDropList
public System.Collections.Specialized.StringCollection
    SwapClipboardFileDropList(
    System.Collections.Specialized.StringCollection replacementList)
{
    System.Collections.Specialized.StringCollection returnList = null;
    if (Clipboard.ContainsFileDropList())
    {
        returnList = Clipboard.GetFileDropList();
        Clipboard.SetFileDropList(replacementList);
    }
    return returnList;
}

// Demonstrates SetImage, ContainsImage, and GetImage.
public System.Drawing.Image SwapClipboardImage(
    System.Drawing.Image replacementImage)
{
    System.Drawing.Image returnImage = null;
    if (Clipboard.ContainsImage())
    {
        returnImage = Clipboard.GetImage();
        Clipboard.SetImage(replacementImage);
    }
    return returnImage;
}

// Demonstrates SetText, ContainsText, and GetText.
public String SwapClipboardHtmlText(String replacementHtmlText)
{
    String returnHtmlText = null;
    if (Clipboard.ContainsText(TextDataFormat.Html))
    {
        returnHtmlText = Clipboard.GetText(TextDataFormat.Html);
        Clipboard.SetText(replacementHtmlText, TextDataFormat.Html);
    }
    return returnHtmlText;
}

' Demonstrates SetAudio, ContainsAudio, and GetAudioStream.
Public Function SwapClipboardAudio( _
    ByVal replacementAudioStream As System.IO.Stream) _
    As System.IO.Stream

    Dim returnAudioStream As System.IO.Stream = Nothing

    If (Clipboard.ContainsAudio()) Then
        returnAudioStream = Clipboard.GetAudioStream()
        Clipboard.SetAudio(replacementAudioStream)
    End If

    Return returnAudioStream

End Function

' Demonstrates SetFileDropList, ContainsFileDroList, and GetFileDropList
Public Function SwapClipboardFileDropList(ByVal replacementList _
    As System.Collections.Specialized.StringCollection) _
    As System.Collections.Specialized.StringCollection

    Dim returnList As System.Collections.Specialized.StringCollection _
        = Nothing

    If Clipboard.ContainsFileDropList() Then

        returnList = Clipboard.GetFileDropList()
        Clipboard.SetFileDropList(replacementList)
    End If

    Return returnList

End Function

' Demonstrates SetImage, ContainsImage, and GetImage.
Public Function SwapClipboardImage( _
    ByVal replacementImage As System.Drawing.Image) _
    As System.Drawing.Image

    Dim returnImage As System.Drawing.Image = Nothing

    If Clipboard.ContainsImage() Then
        returnImage = Clipboard.GetImage()
        Clipboard.SetImage(replacementImage)
    End If

    Return returnImage
End Function

' Demonstrates SetText, ContainsText, and GetText.
Public Function SwapClipboardHtmlText( _
    ByVal replacementHtmlText As String) As String

    Dim returnHtmlText As String = Nothing

    If (Clipboard.ContainsText(TextDataFormat.Html)) Then
        returnHtmlText = Clipboard.GetText(TextDataFormat.Html)
        Clipboard.SetText(replacementHtmlText, TextDataFormat.Html)
    End If

    Return returnHtmlText

End Function

以自訂格式從剪貼簿中擷取資料

使用具有自訂格式名稱的 GetData 方法。此方法僅適用於 .NET Framework 2.0。

您也可以使用預先定義的格式名稱搭配 SetData 方法。如需詳細資訊，請參閱DataFormats。

// Demonstrates SetData, ContainsData, and GetData
// using a custom format name and a business object.
public Customer TestCustomFormat
{
    get
    {
        Clipboard.SetData("CustomerFormat", new Customer("Customer Name"));
        if (Clipboard.ContainsData("CustomerFormat"))
        {
            return Clipboard.GetData("CustomerFormat") as Customer;
        }
        return null;
    }
}

' Demonstrates SetData, ContainsData, and GetData
' using a custom format name and a business object.
Public ReadOnly Property TestCustomFormat() As Customer
    Get
        Clipboard.SetData("CustomerFormat", New Customer("Customer Name"))

        If Clipboard.ContainsData("CustomerFormat") Then
            Return CType(Clipboard.GetData("CustomerFormat"), Customer)
        End If

        Return Nothing
    End Get
End Property

[Serializable]
public class Customer
{
    private string nameValue = string.Empty;
    public Customer(String name)
    {
        nameValue = name;
    }
    public string Name
    {
        get { return nameValue; }
        set { nameValue = value; }
    }
}

<Serializable()> Public Class Customer

    Private nameValue As String = String.Empty

    Public Sub New(ByVal name As String)
        nameValue = name
    End Sub

    Public Property Name() As String
        Get
            Return nameValue
        End Get
        Set(ByVal value As String)
            nameValue = value
        End Set
    End Property

End Class

以多種格式從剪貼簿中擷取資料

使用 GetDataObject 方法。若要使用早於 .NET Framework 2.0 的版本從剪貼簿中擷取資料，必須使用此方法。

// Demonstrates how to use a DataObject to add
// data to the Clipboard in multiple formats.
public void TestClipboardMultipleFormats()
{
    DataObject data = new DataObject();

    // Add a Customer object using the type as the format.
    data.SetData(new Customer("Customer as Customer object"));

    // Add a ListViewItem object using a custom format name.
    data.SetData("CustomFormat",
        new ListViewItem("Customer as ListViewItem"));

    Clipboard.SetDataObject(data);
    DataObject retrievedData = (DataObject)Clipboard.GetDataObject();

    if (retrievedData.GetDataPresent("CustomFormat"))
    {
        ListViewItem item =
            retrievedData.GetData("CustomFormat") as ListViewItem;
        if (item != null)
        {
            MessageBox.Show(item.Text);
        }
    }

    if (retrievedData.GetDataPresent(typeof(Customer)))
    {
        Customer customer =
            retrievedData.GetData(typeof(Customer)) as Customer;
        if (customer != null)
        {
            MessageBox.Show(customer.Name);
        }
    }
}

' Demonstrates how to use a DataObject to add
' data to the Clipboard in multiple formats.
Public Sub TestClipboardMultipleFormats()

    Dim data As New DataObject()

    ' Add a Customer object using the type as the format.
    data.SetData(New Customer("Customer as Customer object"))

    ' Add a ListViewItem object using a custom format name.
    data.SetData("CustomFormat", _
        New ListViewItem("Customer as ListViewItem"))

    Clipboard.SetDataObject(data)
    Dim retrievedData As DataObject = _
        CType(Clipboard.GetDataObject(), DataObject)

    If (retrievedData.GetDataPresent("CustomFormat")) Then

        Dim item As ListViewItem = _
            TryCast(retrievedData.GetData("CustomFormat"), ListViewItem)

        If item IsNot Nothing Then
            MessageBox.Show(item.Text)
        End If

    End If

    If retrievedData.GetDataPresent(GetType(Customer)) Then

        Dim customer As Customer = _
            CType(retrievedData.GetData(GetType(Customer)), Customer)

        If customer IsNot Nothing Then

            MessageBox.Show(customer.Name)
        End If

    End If

End Sub

[Serializable]
public class Customer
{
    private string nameValue = string.Empty;
    public Customer(String name)
    {
        nameValue = name;
    }
    public string Name
    {
        get { return nameValue; }
        set { nameValue = value; }
    }
}

<Serializable()> Public Class Customer

    Private nameValue As String = String.Empty

    Public Sub New(ByVal name As String)
        nameValue = name
    End Sub

    Public Property Name() As String
        Get
            Return nameValue
        End Get
        Set(ByVal value As String)
            nameValue = value
        End Set
    End Property

End Class

共用方式為

如何：從剪貼簿擷取資料

以單一通用格式從剪貼簿中擷取資料

以自訂格式從剪貼簿中擷取資料

以多種格式從剪貼簿中擷取資料

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