WPF Discussion Boards

12-Aug-09 0:25

Dear all,

I've looked around to find an elegant solution to my problem, but not with a log of success... Sigh | :sigh:

I would like to prevent a control (custom label, custom button,...) from being rendered (drawn, painted.. ?) based on a condition (actually, a database linked security check)
but not by using the visibility or opacity properties as I would like to keep these properties freely usable by the users of the control in design mode.

I tried to override OnRender, passing a null drawingContext etc. but it doesn't work.

Does anyone have an idea how to do this ?

Thanks all!

Pete O'Hanlon12-Aug-09 0:37

12-Aug-09 0:37

You could always create an empty style for the control if necessary.

Apply a DataTrigger to apply this style based on your condition.

"WPF has many lovers. It's a veritable porn star!" - Josh Smith

As Braveheart once said, "You can take our freedom but you'll never take our Hobnobs!" - Martin Hughes.

jopiron12-Aug-09 0:43

12-Aug-09 0:43

Yes I investigated this, but how can I reset the style to the default one after ?

The process is quite like this:

public MyLabel()
{
SecurityHandler.Instance.SecurityChanged += new SecurityChangedEventHandler(Instance_SecurityChanged);
}

void Instance_SecurityChanged(object sender, string newUsername, int newSecurityLevel)
{
this.securityVisibilityCheck(); // Should change the style here so
}

Thanks for your quick reply!

Pete O'Hanlon12-Aug-09 0:56

12-Aug-09 0:56

When the condition triggering your data trigger is removed, the default style is automatically reapplied. That't the beauty of triggers - you don't have to write a lot of code to reset things when the condition is no longer true.

"WPF has many lovers. It's a veritable porn star!" - Josh Smith

As Braveheart once said, "You can take our freedom but you'll never take our Hobnobs!" - Martin Hughes.

jopiron12-Aug-09 1:32

12-Aug-09 1:32

Indeed

But unfortunately I do not have a simple trigger to decide, and if I have to handle converters, I prefer to make everything in code.

jopiron12-Aug-09 1:52

What do i need to install silverlight and make it run in visual studio2008

12-Aug-09 1:52

So simple...

Just set object.Style = null;

Thanks all! Laugh | :laugh:

Andile.M11-Aug-09 22:44

Andile.M

11-Aug-09 22:44

I'am trying to develop an asp.net website using silverlight but i've tried to install silverlight but it says i need pre requisites please point me to the correct direction

Re: What do i need to install silverlight and make it run in visual studio2008

Pete O'Hanlon12-Aug-09 0:02

12-Aug-09 0:02

All that you need to download is linked to from this page[^].

"WPF has many lovers. It's a veritable porn star!" - Josh Smith

As Braveheart once said, "You can take our freedom but you'll never take our Hobnobs!" - Martin Hughes.

Re: What do i need to install silverlight and make it run in visual studio2008

Michael Sync12-Aug-09 3:18

Michael Sync

12-Aug-09 3:18

You need to have .NET 3.5 service pack 1 and Visual Studio 2008 service pack 1 before installing Silverlight Tool for Visual Studio.

Thanks and Regards,
Michael Sync ( Blog: http://michaelsync.net)

Microsoft MVP (Silverlight), WPF/Silverlight Insiders

How to use same usercontrol multiple time in the silverlight

Nekkantidivya11-Aug-09 20:40

Nekkantidivya

11-Aug-09 20:40

Hi,

I am working on a silverlight application. In this I need to place usercontrols on a canvas in the Page.xaml page dynamically at run time. Later I need to set the data values for the datagrid on these user controls from the Page.xaml itself. I want to set different data for different user controls.

How can i differentiate these user controls from one another and set differnt data to their datagrid from Page.xaml itself.

please reply me if u have any idea to solve this.

Thanks in advance

Re: How to use same usercontrol multiple time in the silverlight

Pete O'Hanlon11-Aug-09 21:45

11-Aug-09 21:45

There are a couple of ways to do this; it just depends on whether or not you are using pure databinding and MVVM. If you are using MVVM and pure databinding, then there's very little that you need to do because the View/ViewModel integration will take care of the hard work for you. If you aren't, then you can assign a name to each control when you assign it using the x:Name property, e.g. x:Name="myUserControl1" (this is if you add it into the XAML). If you add it using code behind, you just assign the name to the Name property.

"WPF has many lovers. It's a veritable porn star!" - Josh Smith

As Braveheart once said, "You can take our freedom but you'll never take our Hobnobs!" - Martin Hughes.

Re: How to use same usercontrol multiple time in the silverlight

Jeremy Likness13-Aug-09 5:32

Jeremy Likness

13-Aug-09 5:32

Either you are instantiating the objects yourself, and can take them with x:Name and have your own reference, or you are using them in a template in the DataGrid. If you are using them in a template, you can hook into the <coded>Loaded event and do something with them. For example, you might do this:

XML

<DataGrid>...<u:MyControl Loaded="MyControl_Loaded".../>...</DataGrid>

In the MyControl_Loaded you can then take the event arguments and do something with the control, either processing, passing it into a controller, etc.

Jeremy Likness
Latest Article: Whats in Your Collection? Part 1 of 3: Interfaces
Blog: C#er : IMage

Positioning controls on a WPF form

Etienne_12311-Aug-09 10:27

Etienne_123

11-Aug-09 10:27

I have a pretty basic question to which I want a solution.
I have a bunch of controls on a WPF form. Some controls are within a Grid. I want these controls to stay centered within the grid when maximizing and resizing the window, but as soon as I maximize my window the controls get thrown out of position. I know this probably has someting to do with the Margin property of the controls. Can someone just please tell me how to set the margin or any other property so that the controls stay where I want them too

Thanks in advance

Mark Salsbery11-Aug-09 10:59

11-Aug-09 10:59

Etienne_123 wrote:
Some controls are within a Grid. I want these controls to stay centered within the grid when maximizing and resizing the window

What is the parent of the grid with the controls? The parent may
be affecting the layout.

Here's an example of a grid with controls that stays centered in a window:

<Grid HorizontalAlignment="Center" VerticalAlignment="Center" >
    <Grid.RowDefinitions>
        <RowDefinition Height="*" />
        <RowDefinition Height="*" />
    </Grid.RowDefinitions>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="*" />
        <ColumnDefinition Width="*" />
    </Grid.ColumnDefinitions>
    <Button Content="button1" Grid.Column="0" Grid.Row="0" />
    <Button Content="button2" Grid.Column="1" Grid.Row="1" />
</Grid>

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Etienne_12311-Aug-09 21:30

Etienne_123

11-Aug-09 21:30

The parent control is a Groupbox

Mark Salsbery12-Aug-09 6:41

12-Aug-09 6:41

Etienne_123 wrote:
The parent control is a Groupbox

Ok....and how is this groupbox supposed to behave when the window
is resized?

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Pierre Leclercq15-Aug-09 0:53

Pierre Leclercq

15-Aug-09 0:53

Etienne_123 wrote:
The parent control is a Groupbox

Then you should give more details, as a groupbox can have only one child.

You can't turn lead into gold, unless you've built yourself a nuclear plant.

#realJSOP12-Aug-09 2:14

#realJSOP

12-Aug-09 2:14

If you don't want your controls to change size or position, you have to anchor them to *just* the left and top sides of the parent control.

Be aware that if you change the control's position in the designer (as opposed to changing it in the XAML), the designer will make assumptions based on some weird-ass algorithm and will CHANGE the anchors for you. You then have to go back and change them back to what you actually wanted. I've heard that they fixed this behavior in VS2010, but I'm not sure because they claimed they fixed other stuff in 2010, and it *that other stuff) sure as hell ain't fixed.

"Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
-----
"...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001

Re: Positioning controls on a WPF form [modified]

Pierre Leclercq15-Aug-09 0:44

Pierre Leclercq

15-Aug-09 0:44

"Real" WPF coders use notepad to type XAML! Wink | ;)

You can't turn lead into gold, unless you've built yourself a nuclear plant.

Mark Salsbery15-Aug-09 5:58

15-Aug-09 5:58

Notepad is for wimps.

Only little girls need a GUI.

I use ~~"edit"~~ "edlin" from a command prompt.

Poke tongue | ;-P

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

modified on Saturday, August 15, 2009 12:45 PM

How to add runtime events for dynamic textbox controls in wpf [modified]

Pierre Leclercq15-Aug-09 6:26

Pierre Leclercq

15-Aug-09 6:26

ROTFL!

You can't turn lead into gold, unless you've built yourself a nuclear plant.

Veerendranadh11-Aug-09 0:15

Veerendranadh

11-Aug-09 0:15

Hi,
I have a canvas and i am adding dynamic textbox controls to the canvas when the page is loaded. When i was trying to add event handlers (say mousedown event on textbox), the event is not firing when i mousedown on textbox after the page loaded.
I am providing sample code:

I have declared one global textbox name 'tb'.

This is my canvas control:
<Canvas x:Name="CustomizeTools" Grid.Row="1" Height="400" Width="800" Grid.Column="0" Background="Aqua">
</Canvas>

In code behind my logic is like this:
tb = new Textbox();
tb.MouseLeftButtonDown += new System.Windows.Input.MouseButtonEventHandler(tb_MouseLeftButtonDown);
CustomizeTools.Children.Add(tb);

void tb_MouseLeftButtonDown(object sender, System.Windows.Input.MouseButtonEventArgs e)
{
}

But here the mouse events are not firing.

pleae help me. Its urgent.
Thanks in advance

modified on Tuesday, August 11, 2009 6:22 AM

Re: How to add runtime events for dynamic textbox controls in wpf

Pete O'Hanlon11-Aug-09 3:00

11-Aug-09 3:00

The textbox has default behaviours in place for handling the mouse events - what you need to do is handle the PreviewMouseLeftButtonDown event instead. This gets to your handler before the textbox consumes the MouseLeftButtonDown event. It's a simple fix:

tb.PreviewMouseLeftButtonDown += new System.Windows.Input.MouseButtonEventHandler(tb_MouseLeftButtonDown);

Alternitively, you can add your own handler using

tb.AddHandler(UIElement.MouseLeftButtonDownEvent, new RoutedEventHandler(tb_MouseLeftButtonDown),true);

"WPF has many lovers. It's a veritable porn star!" - Josh Smith

As Braveheart once said, "You can take our freedom but you'll never take our Hobnobs!" - Martin Hughes.

Hosting Silverlight Application on IIS

sunil.n.cs10-Aug-09 20:42

sunil.n.cs

10-Aug-09 20:42

Hi,
Can any 1 guide me through how to host an silverlight appl on local IIS ver 5.1. I tried hosting it, the problem is that the web services dosnt work, i dont know if i have hosted the appl properly or not, i have followed same steps as per a ASP.Net appl hosting.

Thanks in advance

Re: Hosting Silverlight Application on IIS

Mark Salsbery11-Aug-09 5:46