Backgroundworker and Delegate (center Text)

[UCPocoAPoco]

Hi All,

I have a BackgroundWorker and using a delegate to update an UI on a different thread. Everything is working except the "lblInfo.Left = (Me.Width / 3) - (lblInfo.Width / 4)".
I need this line since it allows me to center the text on the UI as I have several Subroutines and they all have various lengths in text. If possible, Can someone help me
pass the lblInfo.Left = (Me.Width / 3) - (lblInfo.Width / 4) from the delegate so I don't get a IllegalCrossThread. ANY help will be greatly appreciated.

Thanks in Advance.



Delegate Sub SetLabelTextInvoker(ByVal lblInfo As Label, ByVal Text As String)

Sub SetLabelText(ByVal lblInfo As Label, ByVal Text As String)
If lblInfo.InvokeRequired = True Then
lblInfo.Invoke(New SetLabelTextInvoker(AddressOf SetLabelText), lblInfo, Text)
Else
lblInfo.Text = Text
End If
End Sub


Private Sub BackgroundWorker1_DoWork(ByVal sender As System.Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker1.DoWork

lblInfo.Left = (Me.Width / 3) - (lblInfo.Width / 4) ' line that done work unless I set the Control.CheckForIllegalCrossThreadCalls = False which I don't want to.
SetLabelText(lblInfo, "File is being copied and will take a while. Please Wait...")
BackgroundWorker1.ReportProgress(20)

Copy_5GB_Image()

lblInfo.Left = (Me.Width / 3) - (lblInfo.Width / 4)
SetLabelText(lblInfo, "Image Copied Successfully.")

End Sub

[Mc_VB]

Use an additional parameter for the labels position

Delegate Sub SetLabelTextInvoker(ByVal lblInfo As Label, ByVal Text As String, ByVal lblposition As Integer)

    Sub SetLabelText(ByVal lblInfo As Label, ByVal Text As String, ByVal lblposition As Integer)
        If lblInfo.InvokeRequired = True Then
            lblInfo.Invoke(New SetLabelTextInvoker(AddressOf SetLabelText), lblInfo, Text, lblposition)
        Else
            lblInfo.Text = Text
            lblInfo.Left = lblposition
        End If
    End Sub


    Private Sub BackgroundWorker1_DoWork(ByVal sender As System.Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker1.DoWork
        Dim lblposition As Integer
        lblposition = (Me.Width / 3) - (lblinfo.Width / 4)
        SetLabelText(lblinfo, "File is being copied and will take a while. Please Wait...", lblposition)
        BackgroundWorker1.ReportProgress(20)

       Copy_5GB_Image()


        lblposition = (Me.Width / 3) - (lblinfo.Width / 4)
        SetLabelText(lblinfo, "Image Copied Successfully.", lblposition)

    End Sub

[UCPocoAPoco]

Hi Mc_VB,

It Work like a charm. Thanks a million and one. As simple as it may be to you. I Spent an entire day trying to figure it out. Thanks again and hope your day goes well.

[Mc_VB]

Hi, an alternative that would probably be better would be to calculate the position just once in the SetLabelText Sub, so using your original code remove all instances of lblInfo.Left = (Me.Width / 3) - (lblInfo.Width / 4) and just use it once in your sub routine

 Sub SetLabelText(ByVal lblInfo As Label, ByVal Text As String)

        Dim lblposition As Integer

        If lblInfo.InvokeRequired = True Then
            lblInfo.Invoke(New SetLabelTextInvoker(AddressOf SetLabelText), lblInfo, Text)
        Else
            lblInfo.Text = Text
            lblposition = (Me.Width / 2) - (lblInfo.Width / 4)
            lblInfo.Left = lblposition
        End If

    End Sub

[UCPocoAPoco]

Thanks again MC_VB. I use:

lblposition = (Me.Width / 2) - (lblInfo.Width / 3)
SetLabelText(lblInfo, "File is being copied and will take a while. Please Wait...", lblposition)


As I have several "lblposition" so I can't use one in the subroutine. Thanks for helping me fine tune my code though. Appreciate it.

[DataMiser]

I generally use

Object.Left=(Me.Width-Object.Width)/2

to center an object on a form and in the case of a label I would also set the align property to center.

Not sure how well the code in the posts above works but the code I use works perfectly with any object regaurdless of the content.

[UCPocoAPoco]

Hi DataMiser,

Thanks again. Now you got me alll curious. I use

"Object.Left=(Me.Width-Object.Width)/2" but to no vail.

The below works.

"lblposition = (Me.Width / 2) - (lblInfo.Width / 3)"


How exactly would you do it based on what I have above. Thanks

[DataMiser]

Hi DataMiser,

Thanks again. Now you got me alll curious. I use

"Object.Left=(Me.Width-Object.Width)/2" but to no vail.

The below works.

"lblposition = (Me.Width / 2) - (lblInfo.Width / 3)"


How exactly would you do it based on what I have above. Thanks

What I posted was not intended to be used literally. Object refers to whatever object you are centering. It could be a label, a textbox, a picture, another form or anything else that has these properties. You would use the actual name of your object in place of the word Object.

[fengwilson]

Hello, I am new to the forum.