TextRange.CanSave(String) 方法

定义

命名空间:

System.Windows.Documents

程序集:

PresentationFramework.dll

检查是否可将当前所选内容保存为指定数据格式。

public:
 bool CanSave(System::String ^ dataFormat);

public bool CanSave (string dataFormat);

member this.CanSave : string -> bool

Public Function CanSave (dataFormat As String) As Boolean

参数

dataFormat

String

要检查是否与当前所选内容的保存兼容的数据格式。 请参见 DataFormats 以获得预定义数据格式的列表。

返回

Boolean

如果可将当前所选内容保存为指定数据格式，则为 true；否则为 false。

示例

下面的示例演示 CanSave 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

注解

使用相应的 Save 方法以指定的数据格式实际保存当前所选内容。

另请参阅

• CanLoad(String)
• Load(Stream, String)