TextSelection.IsEmpty 属性

获取指示定位点是否等于活动点的值。

命名空间：  EnvDTE
程序集：  EnvDTE（在 EnvDTE.dll 中）

语法

声明
ReadOnly Property IsEmpty As Boolean

bool IsEmpty { get; }

property bool IsEmpty {
    bool get ();
}

abstract IsEmpty : bool

function get IsEmpty () : boolean

属性值

类型：System.Boolean
一个布尔值，如果定位点等于活动点，则该值为 True，否则为 False。

备注

IsEmpty 返回指示选定文本的定位点和活动端是否在文本文档中的同一位置的值。

示例

Sub IsEmptyExample()
    ' Before running this example, open a text document.
    Dim objSel As TextSelection = DTE.ActiveDocument.Selection
    If objSel.IsEmpty Then
        ' If there is no text selected, swap the words before and after 
        ' the insertion point. We begin by selecting the word before 
        ' the insertion point.
        objSel.WordLeft(True)
        If Not objSel.IsEmpty Then
            ' We can continue only if the selection was not already at 
            ' the beginning of the document.
            Dim strBefore As String = objSel.Text

            ' The text is saved in strBefore; now delete it and move 
            ' past the following word.
            objSel.Delete()
            objSel.WordRight(True)
            If objSel.Text.StartsWith(" ") Or objSel.Text.StartsWith(Microsoft.VisualBasic.ControlChars.Tab) Then
                ' The previous call to WordRight may have skipped some 
                ' white space instead of an actual word. In that case, 
                ' we should call it again.
                objSel.WordRight(True)
            End If

            ' Insert the new text at the end of the selection.
            objSel.Insert(strBefore, vsInsertFlags.vsInsertFlagsInsertAtEnd)
        End If
    Else
        ' If some text is selected, replace the following word with the 
        ' selected text.
        Dim strSelected As String = objSel.Text

        objSel.MoveToPoint(objSel.BottomPoint)
        objSel.WordRight(True)
        If objSel.Text.StartsWith(" ") Or objSel.Text.StartsWith(Microsoft.VisualBasic.ControlChars.Tab) Then
            ' The previous call to WordRight may have skipped some 
            ' white space instead of an actual word. In that case, we 
            ' should call it again.
            objSel.WordRight(True)
        End If

        ' Insert the text, overwriting the existing text and leaving 
        ' the selection containing the inserted text.
        objSel.Insert(strSelected, vsInsertFlags.vsInsertFlagsContainNewText)
    End If
End Sub

.NET Framework 安全性

• 对直接调用方的完全信任。此成员不能由部分信任的代码使用。有关更多信息，请参见通过部分受信任的代码使用库。

请参见

参考

TextSelection 接口

EnvDTE 命名空间