Dim indexOfSearchText As Integer = 0
Dim start As Integer = 0
Private Sub search_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles search.Click
Dim startindex As Integer
start_search:
If TextBox1.Text.Length > 0 Then
startindex = FindMyText(TextBox1.Text.Trim(), start, RichTextBox1.Text.Length)
Else
MsgBox("沒有關鍵字")
GoTo mark_end
End If
' If string was found in the RichTextBox, highlight it
If startindex >= 0 Then
' Set the highlight color
RichTextBox1.SelectionBackColor = Color.GreenYellow
' Find the end index. End Index = number of characters in textbox
Dim endindex As Integer = TextBox1.Text.Length
' Highlight the search string
RichTextBox1.Select(startindex, endindex)
' mark the start position after the position of
' last search string
start = startindex + endindex
GoTo start_search
End If
mark_end:
End Sub
Public Function FindMyText(ByVal txtToSearch As String, ByVal searchStart As Integer, ByVal searchEnd As Integer) As Integer
' Set the return value to -1 by default.
Dim retVal As Integer = -1
' A valid starting index should be specified.
' if indexOfSearchText = -1, the end of search
If searchStart >= 0 AndAlso indexOfSearchText >= 0 Then
' A valid ending index
If searchEnd > searchStart OrElse searchEnd = -1 Then
' Find the position of search string in RichTextBox
indexOfSearchText = RichTextBox1.Find(txtToSearch, searchStart, searchEnd, RichTextBoxFinds.None)
' Determine whether the text was found in richTextBox1.
If indexOfSearchText <> -1 Then
' Return the index to the specified search text.
retVal = indexOfSearchText
End If
End If
End If
Return retVal
End Function
改編自以下網址，感謝原作者。
http://www.dotnetcurry.com/ShowArticle.aspx?ID=146
