我创建了一个查找替换框。这是全部替换按钮

Private Sub BtnreplaceAll_Click(sender As Object,e As EventArgs) Handles BtnreplaceAll.Click

Try
            Dim currentPosition As Integer = frmmain.RichTextBox1.SelectionStart
            Dim currentSelect As Integer = frmmain.RichTextBox1.SelectionLength

            frmmain.RichTextBox1.Text = Replace(Trim(frmmain.RichTextBox1.Text),Trim(txtfind.Text),Trim(txtreplace.Text))

            frmmain.RichTextBox1.SelectionStart = currentPosition
            frmmain.RichTextBox1.SelectionLength = currentSelect
            frmmain.RichTextBox1.ScrollToCaret()
            frmmain.Focus()

            MsgBox("Replace completed",MsgBoxStyle.Information + MsgBoxStyle.OkOnly,"Replace")

        Catch ex As Exception
            MsgBox("Unable to replace","Replace")
        End Try
    End Sub

工作正常。唯一的问题是，如果我写了一些文本并在RichTextBox1中插入图像，然后单击Replace All按钮，它将替换文本并从RichTextBox1中删除图像。 如何防止图像被删除？