I have problem with binding 3 things i xaml.
I want to made something like this:
I choose product from combobox.
Default price from this products is setting in textbox.
Now I want for example change this price and bind it to my object 'newSale'
<TextBox Name="txtSalePrice" InputScope="Digits" Text="{Binding ElementName=cmbProducts, Path=SelectedItem.Price}" \>
<ComboBox x:Name="cmbProducts" ItemsSource="{Binding ListProducts}" DisplayMemberPath="FullName" \>
I want to bind value of textbox to property of object 'NewSale' with property 'price', but without change price in selectedProduct.
I have problem with achieve this.
The easiest way I see is to use another property (Price for example) bound to your TextBox. In you viewmodel, whenever the SelectedItem of your ComboBox changes, set it into Price. And whenever you want to display something else, set manually the value into Price.
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I have on combobox with products, one textbox. In text property of textbox I want to bind selected product's price from combobox. To that moment it can be made for example like this:
<TextBox Name="txtSalePrice" InputScope="Digits" Text="{Binding ElementName=cmbProducts, Path=SelectedItem.Price}" />
<ComboBox x:Name="cmbProducts" ItemsSource="{Binding ListProducts}" DisplayMemberPath="FullName">
Now I want to bind value of textbox to property of some object let's say it's
new sale object 'NewSale' with property 'price', but without change price in selectedProduct.
I have problem with achieve this.
I've got a simple WPF ComboBox, displaying Orders/Positions on the Financial Markets.
<ComboBox Name="TradeDropDown"
HorizontalAlignment="Stretch"
VerticalAlignment="Top"
ItemsSource="{Binding Path=ActiveOrders}"
DisplayMemberPath="OrderLabel"
SelectedItem="{Binding Path=SelectedOrder, Mode=TwoWay}" IsSynchronizedWithCurrentItem="True" />
I need to see at a glance how many items are in the list. I've added a TextBlock above with summary information.
I don't like it, and would prefer to have the items in the dropdown listed like:
(1/2) Working Short 425K
(2/2) Filled Long 979K
etc - and have the 1/2 numbers correctly update as items are added and removed from the list.
The Items are stored in a BindingList.
Is there an easy way to do this?
Is there an easy way to do this?
Add another property to the class where the OrderLabel property is defined that returns a string like "(1/2) Working Short 425K" and set the DisplayMemberPath property of the ComboBox to the name of this property.
Make sure that the class implements the INotifyPropertyChanged interface.
You then set the new property to a new value and raise the PropertyChanged event whenever you want to update the label in the ComboBox.
Imagine your working on a UI for an Wedding Planner app. You'll have a list of guests and you want to display their name on the screen next to a combobox containing values of 'Will Attend' / 'Maybe' / 'No'.
I've tried to something just that....I have a collection of items inside a view model (the guests). For each of those items I want to display a Label and a ComboBox. Each ComboBox has the same values in the drop down (the possible responses).
I've created an ItemTemplate that contains a label and a combobox. I bind it to my collection of guests and it works as expected. I'm using ancestor binding so that the ComboBox's ItemsSource is bound to the list of possible responses. That works great.
What I'm struggling with is how to bind the SelectedItem to get the values the user selects? I want to have a collection of selected values on the ViewModel somehow, but I'm having a lot of trouble finding the correct words to describe this / search for it.
Can anyone help me? Am I going about this the wrong way?
You may create an enum for the attendance state and add an Attendance property to your Guest class:
public enum Attendance
{
Yes,
No,
Maybe
}
public class Guest
{
...
public Attendance Attendance { get; set; } // raise PropertyChanged event if necessary
}
Now you could set the Tag property of the ComboBox items to the appropriate enum value and bind the SelectedValue property:
<ItemsControl.ItemTemplate>
<DataTemplate>
<ComboBox SelectedValue="{Binding Attendance}" SelectedValuePath="Tag">
<TextBlock Tag="Yes">Will Attend</TextBlock>
<TextBlock Tag="No">Won't Attend</TextBlock>
<TextBlock Tag="Maybe">May Attend</TextBlock>
</ComboBox>
</DataTemplate>
</ItemsControl.ItemTemplate>
I have a basic project in WPF.
All it does it retrieve / update products.
As shown in the image below, the user enters an ID, the data is then displayed according to it, and the user is able to change the data and click 'Save Product' to save it to the database.
The GetProduct(int id) function retrieves a product by the ID provided.
The SaveProduct() function saves the changed fields.
Also, there are two DataTemplates:
1) For the ProductModel - includes 3 textboxes: ProductId, ProductName, UnitPrice.
2) For the ProductViewModel - includes the save/get buttons + a textbox for the user to enter the id of the desired product.
What I'm trying to do is get the changed data when a user clicks the 'Save Product' button.
The most ideal way in my opinion, is to use Binding.
Each textbox is already binded, but I have no idea how to get the binded data.
Here is an example of a binded textbox in the FIRST DataType (ProductModel):
<TextBox Grid.Row="0" Grid.Column="1" Text="{Binding ProductId}" Margin="5" Width="150" />
There is one for each of the following properties: ProductId, ProductName and UnitPrice.
IMPORTANT!: The Get/SaveProduct() functions are in the ProductViewModel class, while the actual product class is - you guessed it - ProductModel. The ProductViewModel class holds a variable that contains the current product displayed.
This is the button that's used to save the info - it is written in the SECOND DataType (ProductViewModel):
<Button Content="Save Product" DockPanel.Dock="Right" Margin="10,2" VerticalAlignment="Center" Command="{Binding Path=SaveProductCommand}" Width="100" />
The SaveProductCommand command simply fires the SaveProduct() function.
I have a few questions regarding this whole subject:
What does it mean when a binding is used like this : {Binding ProductId} ?
The default binding mode for textboxes is TwoWay as far as I remember. But in this case, ProductId/Name + UnitPrice are not dependency properties, therefore is it right that the binded values do not update/sent back when the text in the textboxes is changed? (Since there isn't an event attached to it...)
A data context was never configured in my project, but all of the "binding tags" in my XAML pages don't seem to have a defined source. Could it be that the source is actually the DataType in the DataTemplate that includes the binded objects?
The SECOND DataTemplate (the ProductViewModel one) has this ContentControl tag: <ContentControl Margin="10" Content="{Binding Path=CurrentProduct}" />.
What is it's purpose?
If a TwoWay binding were/does occur, how do I get the values from within the SaveProduct() function? Do I just refer to, say CurrentProduct.ProductName to get the changed name?
Much thanks to everyone who takes their time to answer - I appreciate it so much!
What does it mean when a binding is used like this : {Binding
ProductId} ?
The specific control property you have this binding set on is going to look for the ProductId property on the object set as the DataContext and set the propertys value in the control accordingly.
The default binding mode for textboxes is TwoWay as far as I remember.
But in this case, ProductId/Name + UnitPrice are not dependency
properties, therefore is it right that the binded values do not
update/sent back when the text in the textboxes is changed? (Since
there isn't an event attached to it...)
You do not need to make the properties within your object a DependencyProperty for TwoWay binding to occur.
A data context was never configured in my project, but all of the
"binding tags" in my XAML pages don't seem to have a defined source.
Could it be that the source is actually the DataType in the
DataTemplate that includes the binded objects?
The bindings being set within your XAML will use the object stored within the DataContext, thus if you do not explicitly set the DataContext of the view, it will be null. You should note however that the DataContext is inherited from its parent. If you are in fact setting the content by using say, CurrentProduct, then all the properties will be available to bind to per your Product type.
The SECOND DataTemplate (the ProductViewModel one) has this
ContentControl tag:
<ContentControl Margin="10" Content="{Binding Path=CurrentProduct}" />
What is it's purpose?
It is acting as the container of your CurrentProduct, which can contain one and only one item.
If a TwoWay binding were/does occur, how do I get the values from
within the SaveProduct() function? Do I just refer to, say
CurrentProduct.ProductName to get the changed name?
Without seeing the entire application, my guess is that the ContentControl is being set to the CurrentProduct and your TextBox, etc.. are all bound to the respective properties, such as CurrentProduct.ProductId, etc... The product which you want to save is in fact the CurrentProduct. When you call save within your ViewModel, you simply access the CurrentProduct and persist it as needed, where CurrentProduct.PropertyName will contain the changes which were propagated from the UI.
I have a combo box which is populated on selection's from two other combo'.
No problem I have this working.
Problem is I only want to activate the Selected Item binding after this has happened.
Here is my combo
<cuc:ComboBox Name="GopLenTypeCombo" Width="240" Height="24"
IsSynchronizedWithCurrentItem="True"
SelectedValue="{Binding Mode=TwoWay, Source={StaticResource ProfileDataProvider}, XPath=GopLenType}"
IsEnabled="False"/>
How do I stop the SelectedValue binding working untill I have populated the combo ?
I don't know whether this is possible in pure XAML, but if you have an underlying ViewModel, this wouldn't be too hard:
What you would need to do is to bind your third ComboBox to a property on the ViewModel (let's call this property Combo3Items).
You would also need to bind the two first ComboBoxes to properties on the same ViewModel (let's call these Combo1Items and Combo2Items, respectively). In addition to that, you could bind both of these ComboBoxes' SelectedValue to properties on the ViewModel, so that the ViewModel knows which items are selected.
Initially, Combo3Items would be empty, but as soon as the two bound SelectedValues are properly assigned, you can fill Combo3Items and raise an INotifyPropertyChanged event.
The MVVM architecture is very powerful. If you don't already know it, you can read more about it here.