Controlling GUI via text file ? - C# Discussion Boards

23-Jul-07 21:28

I have an application. it has two forms. first form - mainForm is big and some images are loading into mainForm. second form - loginForm should be showed while mainForm is invisible is loading.
loginForm has a label that has "Loading...".

all is working but this label on the loginForm is not visible few seconds and I guess apllication is not response, but then all is ok. label is visible and formLogin to. after loading of maiForm is complete , loginForm should be hide..

can I fix waiting of showing of the label on the formLogin? is there somethig like "Application.ProcessMessagess" in Delphi?

thanx!

--
"Success is simple. Do what's right, the right way, at the right time."

best regards,
tradakad

Christian Graus23-Jul-07 22:18

Christian Graus

23-Jul-07 22:18

Application.DoEvents.

Getting your init to happen on another thread, is even better.

Christian Graus - Microsoft MVP - C++

"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )

tradakad23-Jul-07 23:02

23-Jul-07 23:02

Thanx!
I tryed - but it doesnt work Frown | :(

it is my loginForm

public partial class frmLoading : Form
{
private int pointCount = 0;
private int iterationsCount = 0;

public frmLoading()
{
InitializeComponent();
}

private void frmLoading_Load(object sender, EventArgs e)
{
Application.DoEvents();
}

private void frmLoading_Shown(object sender, EventArgs e)
{
Application.DoEvents();
tmrProcess.Enabled = true;
}

private void tmrProcess_Tick(object sender, EventArgs e)
{
Application.DoEvents();

if (iterationsCount <= 2)
{
if (pointCount <= 10)
{
lblLoadingText.Text += ".";
pointCount++;
tmrProcess.Enabled = true;
}
else
{
lblLoadingText.Text = "Loading";
iterationsCount++;
pointCount = 0;

}
}

}
}

--
"Success is simple. Do what's right, the right way, at the right time."

best regards,
tradakad

Martin#23-Jul-07 23:20

23-Jul-07 23:20

Hello,

tradakad wrote:
private void tmrProcess_Tick(object sender, EventArgs e)
{
Application.DoEvents();

if (iterationsCount <= 2)
{
if (pointCount <= 10)
{
lblLoadingText.Text += ".";
pointCount++;
tmrProcess.Enabled = true;
}
else
{
lblLoadingText.Text = "Loading";
iterationsCount++;
pointCount = 0;

}
}

}

You should call the DoEvents at the end of the code!

tradakad wrote:
private void frmLoading_Shown(object sender, EventArgs e)
{
Application.DoEvents();

tradakad wrote:
private void frmLoading_Load(object sender, EventArgs e)
{
Application.DoEvents();
}

I don't think that this is neccessary!

Apart from that, you are using the Forms.Timer which is running in the GUI Thread.
So the Timer is influenced from the action in you thread and might be throwing the Tick event not as expected (delayed)!

You could use a System.Threading or System.Timers Timer, which are running in an own thread.
Therefore you would have to invoke the Form if you want to change the Text, from the elapsed event for example!

All the best,

Martin

tradakad24-Jul-07 0:41

24-Jul-07 0:41

I tryed this.

private int pointCount = 0;
private int iterationsCount = 0;
public System.Timers.Timer tmrLoading = new System.Timers.Timer();

public frmLoading()
{
InitializeComponent();
}

private void frmLoading_Load(object sender, EventArgs e)
{
tmrLoading.Interval = 100;
}

private void frmLoading_Shown(object sender, EventArgs e)
{
tmrLoading.Start();
tmrLoading.Elapsed +=new System.Timers.ElapsedEventHandler(tmrLoading_Elapsed);
}

void tmrLoading_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
{
Application.DoEvents();

if (iterationsCount <= 2)
{
if (pointCount <= 10)
{
this.lblLoadingText.Text += ".";
pointCount++;
tmrLoading.Start();
}
else
{
this.lblLoadingText.Text = "Loading";
iterationsCount++;
pointCount = 0;

}
}

//throw new Exception("The method or operation is not implemented.");
}

but i had an error in this row
- this.lblLoadingText.Text += ".";

"Cross-thread operation not valid: Control 'lblLoadingText' accessed from a thread other than the thread it was created on"

what i do incorrect?

--
"Success is simple. Do what's right, the right way, at the right time."

best regards,
tradakad

Martin#24-Jul-07 0:56

24-Jul-07 0:56

Like I said, you have to invoke the method.
Invoke() is a member of control.
this.Invoke ... when this is your Form

All the best,

Martin

Martin#24-Jul-07 1:13

24-Jul-07 1:13

Hello,

I would add a method which sets the Text, and check there if Invoke is required.

private delegate void SetLoadingTextDelegate(string actText, bool append);
 
privat void SetLoadingText(string actText, bool append)
{
    //Is Invoke neccessary?
    if(InvokeRequired)
    {
        //Do the Invokation and end the method. It will be called again in the GUI thread over the delegate!
        Invoke(new SetLoadingTextDelegate(EnableTimer), new object[] {actText, append});
        return;
    }
    if(append)
    {
        this.lblLoadingText.Text += actText;
    }
    else
    {
        this.lblLoadingText.Text = actText;
    }
}
 
void  tmrLoading_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
{
    if (iterationsCount <= 2)
    {
        if (pointCount <= 10)
        {
            SetLoadingText(".", true);
            pointCount++;
            tmrLoading.Start();
        }
        else
        {
            SetLoadingText("Loading", false);
            iterationsCount++;
            pointCount = 0;
        }
    }
    Application.DoEvents();
}

Hope it helps!

All the best,

Martin

tradakad24-Jul-07 1:38

24-Jul-07 1:38

aha.. i tryed to use property but not method...

ok. i'll it to. thanx!

but why thys code dont work?

public partial class frmLoading : Form
{
private int pointCount = 0;
// private int iterationsCount = 0;
private System.Timers.Timer tmrLoad = new System.Timers.Timer();

public frmLoading()
{
InitializeComponent();
}

private void frmLoading_Shown(object sender, EventArgs e)
{
tmrLoad.Interval = 1000;
ChangeLabelText();
}

private void ChangeLabelText()
{

for (; ; )
{
if (pointCount <= 10)
{
lblLoadingText.Text += ".";
tmrLoad.Start();
pointCount++;
Application.DoEvents();
}
else
{
lblLoadingText.Text = "Loading";
iterationsCount++;
pointCount = 0;

}
}

}
}

main form --------------------

private void frmMain_Load(object sender, EventArgs e)
{
this.Visible = false;
}

private void frmMain_Shown(object sender, EventArgs e)
{
frm.Visible = true;
LoadSettings();
LoadImages();
LoadControlsPositions();
frm.Dispose();
this.Visible = true;

}

--
"Success is simple. Do what's right, the right way, at the right time."

best regards,
tradakad

Martin#24-Jul-07 1:52

24-Jul-07 1:52

Sorry, I have no idea what you try to do here!
What is the timer doing here? You haven't added a eventhandler forthe timer.

All the best,

Martin

tradakad24-Jul-07 2:08

24-Jul-07 2:08

ok. timer can go to hell Smile | :)

I want that main form is invisible while images are loading. so I do this:

private void frmMain_Load(object sender, EventArgs e)
{
this.Visible = false;
}

right?

and after images are loading - form must be showed. so

private void frmMain_Shown(object sender, EventArgs e)
{
LoadSettings();
LoadImages();
LoadControlsPositions();
this.Visible = true;

}

right?

--
"Success is simple. Do what's right, the right way, at the right time."

best regards,
tradakad

Martin#24-Jul-07 2:18

24-Jul-07 2:18

Like Christian said at the beginning, you should use "Application.DoEvents();".

private void frmMain_Load(object sender, EventArgs e)
{
     this.Visible = false;
     Application.DoEvents();
}

tradakad wrote:
private void frmMain_Shown(object sender, EventArgs e)
{
LoadSettings();
LoadImages();
LoadControlsPositions();
this.Visible = true;

}

Again, DoEvents. But which event are you connected too?

All the best,

Martin

tradakad24-Jul-07 2:26

24-Jul-07 2:26

Martin# wrote:
Again, DoEvents. But which event are you connected too?

while main from is hiding - i show loadingForm

private void frmMain_Shown(object sender, EventArgs e)
 {
     frm.Visible = true;
     Application.DoEvents();
     LoadSettings();
     LoadImages();
     LoadControlsPositions();
     frm.Dispose();
     this.Visible = true;


 }

and if dont write Application.DoEvents(); label ot the loading form is not visible Frown | :(

when LoadControlsPositions(); is complete - i kill frm and show the main form again..

--
"Success is simple. Do what's right, the right way, at the right time."

best regards,
tradakad

tradakad23-Jul-07 23:58