Re: Add Controls Dynamically Using MVVM - WPF Discussion Boards

dasblinkenlight3-Feb-11 8:50

dasblinkenlight

3-Feb-11 8:50

In the code where you read your rows, add something like this:

    // ...
    foreach (var row in myRows) {
        var btn = new Button {Content=row.ButtonCaption};
        btn.Click += NotifyButtonCallback;
        pnlControls.Children.Add(btn);
        var txt = new TextBox {Text=row.TextBoxText};
        pnlControls.Children.Add(txt);
    }
    // ...

private void NotifyButtonCallback(object sender, RoutedEventArgs e) {
    //...
}

You will need some additional "bookkeeping" to establish a connection between a UI element that you create dynamically and the row from which you created it, so that you could act upon user's actions, such as editing the text or clicking a button.

Kevin Marois3-Feb-11 9:04

Kevin Marois

3-Feb-11 9:04

But the problem is that pnlControls is not accessable from within the ViewModel.

Everything makes sense in someone's mind

RobCroll3-Feb-11 13:37

RobCroll

3-Feb-11 13:37

You should really handle this in the View not the ModelView. The ModelView should be independent of the View. MVVM light has a nice messenger pattern which you can use. Basically when the ModelView determines a new control needs to be added, it transmits a message which the View subscribes to. The View receives the message and then adds the control.

I'm not a huge fan of MVVM so others may argue the point but that's how I do it.

"You get that on the big jobs."

_Maxxx_3-Feb-11 15:31

_Maxxx_

3-Feb-11 15:31

You need to bind to a collection in your viewmodel and use a DataTemplate to describe how the buttons are to be displayed.

If it wasn't for the fact that I'm in the middle of debugging MS Access programs, I'd probably be able to find an example!!

___________________________________________
.\\axxx
(That's an 'M')

Help editing Xml file from code - C#

_Maxxx_3-Feb-11 15:54

_Maxxx_

3-Feb-11 15:54

Got bored with the MS Access - here's a real simple example...

The temnplate tells it how to display. THe vm has an Options property containing a collection of Option - each of which has an OptionName property

<base:BaseView.Resources>
    <DataTemplate x:Key="ButtonTemplate">
        <Grid>
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="100" />
            </Grid.ColumnDefinitions>
            <Button  Content="{Binding OptionName}" Height="32"/>
        </Grid>
    </DataTemplate>

</base:BaseView.Resources>

<StackPanel Background="#FFFF00" Height="150">
	<ItemsControl  ItemsSource="{Binding Options}"
			ItemTemplate="{StaticResource ButtonTemplate}">
			<ItemsControl.ItemsPanel>
				<ItemsPanelTemplate>
					<StackPanel Orientation="Vertical" HorizontalAlignment="Center" />
				</ItemsPanelTemplate>
			</ItemsControl.ItemsPanel>
	</ItemsControl>
</StackPanel>

Hope that's enough to get you started - you need to work out how you're going to handle clicks, of course... each button may bind to the same command with a varying parameter, or each to its own command - I haven't done this bit (back to the MS Access now!)

___________________________________________
.\\axxx
(That's an 'M')

jadughar3-Feb-11 5:46

jadughar

3-Feb-11 5:46

Hi
I'm trying to modify an Xml file. This is the content of the Xml. The problem is that after changes, it will creates a copy of the content of the Xml file without changing the old content.

Before changes :

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <connectionStrings>
    <add name="Application.Properties.Settings.DBConnectionString"
      connectionString="Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\DB.mdb"
      providerName="System.Data.OleDb" />
  </connectionStrings>
</configuration>

After changes :

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <connectionStrings>
    <add name="Application.Properties.Settings.DBConnectionString"
      connectionString="Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\DB.mdb"
      providerName="System.Data.OleDb" />
  </connectionStrings>
</configuration>
<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <connectionStrings>
    <add name="Application.Properties.Settings.DBConnectionString"
      connectionString="Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\DataBase\DB.mdb"
      providerName="System.Data.OleDb" />
  </connectionStrings>
</configuration>

The code is :

//xml document object
System.Xml.XmlDocument xdoc = new System.Xml.XmlDocument();

FileStream reader = new FileStream(this._XmlFilePath, FileMode.Open, FileAccess.ReadWrite);

xdoc.XmlResolver = null;

//load the xml file
xdoc.Load(reader);

System.Xml.XmlElement Node = (System.Xml.XmlElement)xdoc.DocumentElement.SelectSingleNode("//configuration/connectionStrings/add[@name=\"Application.Properties.Settings.DBConnectionString\"]");
if (Node != null)
{
    //key found, set the value
    Node.Attributes.GetNamedItem("Source").Value = "C:\DataDabe\DB.mdb";

    //finally, save the new version of the config file
    xdoc.Save(reader);
    reader.Close();
}

"For as long as men massacre animals, they will kill each other. Indeed, he who sows the seed of murder and pain cannot reap joy and love." Pythagoras

Pete O'Hanlon3-Feb-11 8:03

Pete O'Hanlon

3-Feb-11 8:03

Nope. I don't see what this has to do with WPF or Silverlight. Wrong forum I'm afraid.

I'm not a stalker, I just know things. Oh by the way, you're out of milk.

Forgive your enemies - it messes with their heads

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RobCroll3-Feb-11 13:54

RobCroll

3-Feb-11 13:54

Check out the ConfigurationManager class. It looks like you are trying to edit the app.config file and this would be a better approach.

"You get that on the big jobs."

Abhinav S3-Feb-11 20:30

Abhinav S

3-Feb-11 20:30

You've got the wrong forum unfortunately.
This is the XAML forum and not the XML forum.
Wink | ;)

The funniest thing about this particular signature is that by the time you realise it doesn't say anything it's too late to stop reading it.

My latest tip/trick

jadughar3-Feb-11 21:26

jadughar

3-Feb-11 21:26

Oh sorry..this was an Window form application...wrong forum

sorry again
bye

"For as long as men massacre animals, they will kill each other. Indeed, he who sows the seed of murder and pain cannot reap joy and love." Pythagoras

wpf

arkiboys2-Feb-11 11:54

2-Feb-11 11:54

I have populated a combo box as follows:

<ComboBox Height="23" HorizontalAlignment="Left" Margin="120,6,0,0"
Name="cboHealth" SelectedIndex="{Binding Path=HealthLevelID}"
VerticalAlignment="Top" Width="256" />

private void PopulateHealthLevels()
{
List<clsDetails> healthlevels = new List<clsDetails>();
healthlevels = clsAccess.GetHealthLevels();
foreach (clsDetails details in healthlevels)
{
cboHealth.Items.Add(details.HealthLevelName);
}
}

The datatable returns the HealthLevelID field as well as otherr fields.
HealthLevelID has values of 1 and 2 for Normal and unNormal respectively.
The combo box does get populated but it does not show the correct item for the selected row.
What am I doing wrong please?
Thanks

Re: wpf

Pete O'Hanlon3-Feb-11 0:04

Pete O'Hanlon

3-Feb-11 0:04

A couple of things here.

1. Your title needs some work. Simply stating wpf is not enough.
2. The code should be enclosed in pre tags.

Now, your problem lies in the fact that SelectedIndex is actually zero based, so your values will not match. SelectedIndex should only be used to indicate the relative position of the object in your collection.

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Forgive your enemies - it messes with their heads

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Re: wpf

arkiboys3-Feb-11 0:17

wpf, populate combobox accordingly

3-Feb-11 0:17

Hi,
At present the HealthLevelID has only values 1 or 2 in it's tblHealthlevels table.
Do you mean that since I am using selectedindex in xamml, I can change the integer values in the sql server table to be 0 and 1 instead of 1 and 2 and then it will work? If so, what if I add more values in the table such as 1, 2, 3, 4, ...
Will my existing xaml work ok?
Thanks

arkiboys3-Feb-11 10:48

Re: wpf, populate combobox accordingly

3-Feb-11 10:48

I did do what you mentioned but still unable to solve this issue.
Any thoughts please?

Pete O'Hanlon3-Feb-11 11:47

Pete O'Hanlon

3-Feb-11 11:47

Rather than relying on the selected index, I prefer to use a selected item.

I'm not a stalker, I just know things. Oh by the way, you're out of milk.

Forgive your enemies - it messes with their heads

My blog | My articles | MoXAML PowerToys | Onyx

Re: wpf, populate combobox accordingly

arkiboys3-Feb-11 11:52