Public Class Form2
    Inherits System.Windows.Forms.Form
    Dim pos As Integer
    Dim tpos As Integer = 1
    Dim num As Integer
    Dim form3 As New form3
    End Sub
  Private Sub findtext(ByVal start As Integer)  '查找
        Dim text2 As String
        text2 = TextBox1.Text
        pos = InStr(start, form3.RichTextBox1.Text, text2)

        If pos > 0 Then
            tpos = pos

            form3.RichTextBox1.SelectionStart = tpos - 1
            form3.RichTextBox1.SelectionLength = Microsoft.VisualBasic.Len(text2)
            form3.RichTextBox1.Focus()
        Else
            MsgBox("查找完毕!" & "共找到" & num & "个!")
            'TextBox1.Focus()
        End If
    End Sub
    Private Sub findtext1(ByVal start As Integer)  '替换
        Dim text2, text3 As String
        text2 = TextBox1.Text
        text3 = TextBox2.Text

        pos = InStr(start, form3.RichTextBox1.Text, text2)
        If pos > 0 Then
            tpos = pos

            form3.RichTextBox1.SelectionStart = tpos - 1
            form3.RichTextBox1.SelectionLength = Microsoft.VisualBasic.Len(text2)
            form3.RichTextBox1.Focus()
            form3.RichTextBox1.SelectedText = text3
        Else
            MsgBox("替换完毕!" & "共替换" & num & "个!")
            'TextBox1.Focus()
        End If
    End Sub
   Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click '查找按钮
        findtext(1)
        If pos > 0 Then
            num = 1
        End If
    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click '查找下一个按钮
        findtext(tpos + Len(TextBox1.Text))
        num += 1
    End Sub
   Private Sub TextBox2_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox2.TextChanged
        num = 0
    End Sub
    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        '替换按钮
        findtext(1)
        findtext1(tpos)
        num += 1
    End Sub
   Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged
        num = 0
    End Sub
如果被查询的窗口只有一个则行的通,
但如果象多文档编辑器有很多个文档该如何确定要查找的是哪个文档?