Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Me.Visible = True
        Dim ed As Editor = Application.DocumentManager.MdiActiveDocument.Editor
        Dim db As Database = Application.DocumentManager.MdiActiveDocument.Database
        Using trans As Transaction = db.TransactionManager.StartTransaction()
            Try
                Dim Values() As TypedValue = {New TypedValue(DxfCode.Start, "TEXT")}
                Dim prFilter As SelectionFilter = New SelectionFilter(Values)
                Dim res As PromptSelectionResult = ed.SelectAll(prFilter)
                If res.Status = PromptStatus.Error Then GoTo skip

                Dim SS As SelectionSet = res.Value
                Dim idarray As ObjectId() = SS.GetObjectIds()
                For i As Integer = 0 To idarray.Length - 1
                    Dim id As ObjectId = res.Value.Item(i).ObjectId
                    Dim ent1 As DBText = DirectCast(trans.GetObject(id, OpenMode.ForWrite), DBText)

                    If Trim(ent1.TextString) = Trim(TextBox1.Text) Then
                        ent1.TextString = Trim(TextBox2.Text)
                    Else
                    End If

                Next
            Finally
                trans.Commit()
            End Try
            trans.Dispose()
        End Using
skip:   Mtext()
        Me.Visible = False
    End Sub
    Sub Mtext()
        Dim ed As Editor = Application.DocumentManager.MdiActiveDocument.Editor
        Dim db As Database = Application.DocumentManager.MdiActiveDocument.Database
        Using trans As Transaction = db.TransactionManager.StartTransaction()
            Try
                Dim Values() As TypedValue = {New TypedValue(DxfCode.Start, "MTEXT")}
                Dim prFilter As SelectionFilter = New SelectionFilter(Values)
                Dim res As PromptSelectionResult = ed.SelectAll(prFilter)
                If res.Status = PromptStatus.Error Then Exit Sub

                Dim SS As SelectionSet = res.Value
                Dim idarray As ObjectId() = SS.GetObjectIds()
                For i As Integer = 0 To idarray.Length - 1
                    Dim id As ObjectId = res.Value.Item(i).ObjectId

                    Dim ent As MText = DirectCast(trans.GetObject(id, OpenMode.ForWrite), MText)
                    If Trim(ent.Contents) = Trim(TextBox1.Text) Then
                        ent.Contents = Trim(TextBox2.Text)
                    Else
                    End If

                Next
            Finally
                trans.Commit()
            End Try
            trans.Dispose()
        End Using
    End Sub