TextRange.Load(Stream, String) 方法

定義

命名空間:

System.Windows.Documents

組件:

PresentationFramework.dll

從指定的資料流載入指定之資料格式的目前選取範圍。

public:
 void Load(System::IO::Stream ^ stream, System::String ^ dataFormat);

public void Load (System.IO.Stream stream, string dataFormat);

member this.Load : System.IO.Stream * string -> unit

Public Sub Load (stream As Stream, dataFormat As String)

參數

stream

Stream

包含要載入目前選取範圍之資料的可讀取資料流。

dataFormat

String

載入資料時要採用的資料格式。 目前支援的資料格式有 Rtf、Text、Xaml 和 XamlPackage。

例外狀況

ArgumentNullException

當 stream 或 dataFormat 是 null 時發生。

ArgumentException

當指定的資料格式不受支援時發生。 如果從 stream 載入的內容與指定的資料格式不符也會發生。

範例

下列範例示範 Load 方法的用法。

// This method accepts an input stream and a corresponding data format.  The method
// will attempt to load the input stream into a TextRange selection, apply Bold formatting
// to the selection, save the reformatted selection to an alternat stream, and return 
// the reformatted stream.  
Stream BoldFormatStream(Stream inputStream, string dataFormat)
{
    // A text container to read the stream into.
    FlowDocument workDoc = new FlowDocument();
    TextRange selection = new TextRange(workDoc.ContentStart, workDoc.ContentEnd);
    Stream outputStream = new MemoryStream();

    try
    {
        // Check for a valid data format, and then attempt to load the input stream
        // into the current selection.  Note that CanLoad ONLY checks whether dataFormat
        // is a currently supported data format for loading a TextRange.  It does not 
        // verify that the stream actually contains the specified format.  An exception 
        // may be raised when there is a mismatch between the specified data format and 
        // the data in the stream. 
        if (selection.CanLoad(dataFormat))
            selection.Load(inputStream, dataFormat);
    }
    catch (Exception e) { return outputStream; /* Load failure; return a null stream. */ }

    // Apply Bold formatting to the selection, if it is not empty.
    if (!selection.IsEmpty)
        selection.ApplyPropertyValue(TextElement.FontWeightProperty, FontWeights.Bold);

    // Save the formatted selection to a stream, and return the stream.
    if (selection.CanSave(dataFormat))
        selection.Save(outputStream, dataFormat);

    return outputStream;
}

' This method accepts an input stream and a corresponding data format.  The method
' will attempt to load the input stream into a TextRange selection, apply Bold formatting
' to the selection, save the reformatted selection to an alternat stream, and return 
' the reformatted stream.  
Private Function BoldFormatStream(ByVal inputStream As Stream, ByVal dataFormat As String) As Stream
    ' A text container to read the stream into.
    Dim workDoc As New FlowDocument()
    Dim selection As New TextRange(workDoc.ContentStart, workDoc.ContentEnd)
    Dim outputStream As Stream = New MemoryStream()

    Try
        ' Check for a valid data format, and then attempt to load the input stream
        ' into the current selection.  Note that CanLoad ONLY checks whether dataFormat
        ' is a currently supported data format for loading a TextRange.  It does not 
        ' verify that the stream actually contains the specified format.  An exception 
        ' may be raised when there is a mismatch between the specified data format and 
        ' the data in the stream. 
        If selection.CanLoad(dataFormat) Then
            selection.Load(inputStream, dataFormat)
        End If
    Catch e As Exception ' Load failure return a null stream. 
        Return outputStream
    End Try

    ' Apply Bold formatting to the selection, if it is not empty.
    If Not selection.IsEmpty Then
        selection.ApplyPropertyValue(TextElement.FontWeightProperty, FontWeights.Bold)
    End If

    ' Save the formatted selection to a stream, and return the stream.
    If selection.CanSave(dataFormat) Then
        selection.Save(outputStream, dataFormat)
    End If

    Return outputStream
End Function

備註

如果 CanSeek 為 truestream ，則會將內容從資料流程的開頭載入至資料流程結尾。 否則，內容將會從目前的 Position 讀取到資料流程結尾。 當這個方法傳回時， stream 會保持開啟狀態，而且內的 stream 目前位置未定義。

載入作業會將目前的選取範圍取代為新載入的內容。

另請參閱

• CanLoad(String)
• Save(Stream, String)
• CanSave(String)