VB.NET:语法突出显示

Question

我开始学习 VB.NET，并且正在尝试进行语法突出显示。当我设置所选文本的颜色时出现问题。它改变了整个富文本框的内容。

Private Sub txtText_TextChanged_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles rtbText.TextChanged
    Dim keywords As ArrayList
    Dim index As Integer
    Dim keyboardCursorPosition As Integer

    keywords = New ArrayList()

    keywords.Add(New Keyword("<?php", Color.Red))
    keywords.Add(New Keyword("echo", Color.Blue))
    keywords.Add(New Keyword("?>", Color.Red))

    keyboardCursorPosition = rtbText.SelectionStart

    For Each keyword As Keyword In keywords
        index = rtbText.Text.IndexOf(keyword.getKey())

        If index <> -1 Then
            rtbText.Select(index, keyword.getKey().Length)
            rtbText.SelectionColor = keyword.getColor()

            rtbText.DeselectAll()
            rtbText.SelectionStart = keyboardCursorPosition
        End If

    Next
End Sub

Answer 1

你们已经很接近了。不要忘记恢复 SelectionColor:

    Dim prevColor As Color = rtbText.SelectionColor
    For Each keyword As KeyWord In keywords
        '' etc...
    Next
    rtbText.SelectionColor = prevColor

顺便说一句:保持代码干净。 rtb 的消息处理程序不应命名为 txtXxxx。这些小细节迟早会把你搞砸(对我来说就是这样，寻找错误的原因)。还将关键字初始化移出方法。