I am a WPF novice.
I have created a form containing a combo box with which to choose a multi-field key value(populated from an XML data file).
I have also created a second WPF form which is available to display all field values from the record associated with the multi-field key value chosen from the first form.
I need to be able to click a button which will cause the second form to be displayed, with all fields filled in which are associated with the chosen key field values.
How do I go about writing such an event trigger using C#?
couple of steps (this is not really MVVM, BTW) ...
first, add a click handler to your button
second, in the click handler code, instantiate your new form
third, set the data context, etc for the new form
forth, show the new form by calling .Show()
in your xaml add a click handler to the button in question....
<Button Click="myClickHandler"/>
in visual studio, you can right click the text in the click="" and choose to navigate to the handler and visual studio will generate the code for it for you.
in your click handler, in code behind, do something like this....
public void myClickHandler(object sender,EventArgs)
{
MySecondForm form = new MySecondForm();
form.DataContext = theDataContextIWantToSet;
form.Show();
}
Related
For a simple borrowed item database, I am trying to link two forms together via a button 'Return'
However, the button does not apply a filter to the correct Item.
In the main menu their is a subform that shows the list of borrowed item via a Query. The list of borrowed Items is a continuous form with the button 'return'
The following event is used when the button is clicked:
OpenForm
form nameReturn
View Form
Data mode Edit
window mode Normal
searchforrecord
object type form
object name return
record First
Where condition = ="[Item_ID]="&[Item_ID]
In that situation access does not apply a filter, after some tutorials I discovered another methode and tested it.
OpenForm
form nameReturn
View Form
Where condition = ="[Item_ID]="&[Item_ID]
Data mode Edit
window mode Normal
in that situation a filter is applied but it does not find any records. Could anyone help in what i did wrong to find link the two forms that use the same table?
I'm new to Visual Basic, I have scoured the net to look for the event handler for the combo box click event but I cannot locate it. I am trying to make an event happens if a certain index is selected with the combo box1 then another combo box2 will populate the selected the index.
i have looked at links like these but it does not explain how or what the person did to access the _ click event VB6 Combo box events
In the code window for the form, select the desired control from the left drop down, then the event you want from the list of all events in the right drop down:
It will create the procedure for you and make it the active one. This is the same as VB.NET assuming you have the selectors on.
I haven't been using VB6 for ages, but i think what you need is covered here: http://www.vb6.us/tutorials/visual-basic-combo-box-tutorial
I cannot recall having to do anything special when using click events in VB6 at all.
In the first combobox click event, you should be able to have an if statement checking if a certain item is selected using .ListIndex and if so, populate the other.
I have just started using visual studio c++ (2010) with windows forms, but have cannot for the life of me find out how to create new UI items in response to events. What I would want to happen is click a button, and have a new row, with a couple of text boxes and buttons appear, with onebutton to delete the row if I keep clicking, more rows will appear, named row0, row1 etcv. I looked at this page, (http://msdn.microsoft.com/en-us/library/aa984255(v=vs.71).aspx), about adding controls programmatically, but when I add a new text box inside a click event, the text box is only created inside the scope of the event (as expected!), but I want to be able to create it insde the newRow click event, but access it and . I thought of making a 'row' class, with row.text and row.deleteButton properties, and at each creation of a row, respective events will be created for button clicks and text edits.
Is there anyway to do this, ie a function that can be created that creates new objects by passing the required name?
The trick for this to work is that you need to have declarations outside of the event handler to keep track of the newly added UI components. In the link you've given the added TextBox is locally scoped within the event function, and this will be removed from the heap (i.e. memory) when the event is finished.
So one solution would be to add a list of UI components to your form, and then have the events add to or remove from this list of components. To get this solution working you possibly need to read up on lists of objects (or possibly dictionaries) and how to handle these.
Sorry for a rather general answer, but the question is also very broad... :)
How can I reset my viewmodel when the user clicks new button on the view that has the viewmodel as it's datacontext?
For example:
If I have a view NewCustomer and upon save, the data is saved to the DB and the newly created account number is displayed. But when the user clicks the New button in the screen, I want the view (viewmodel) to be reinitialized. Or if the user clicked cancel in the screen to clear all changes.
How can I achieve this? I am using Prism 5.0 and Unity as my container.
If I used IRegionMemberLifetime, I can clear the viewmodel data when I navigate away and navigate again to the view (by setting the KeepAlive as false on clicking New button before navigating away). But I want the form to be cleared without navigating. Can this be done?
You could have a screen/workspaceViewModel, and another ViewModel wrapping your data.
So two classes: CarScreenViewModel and CarViewModel.
The CarScreenViewModel would have a property, say CurrentCar, which reflects what is currently selected in the screen. Then, when clicking the Create button, you simply set:
CurrentCar = new CarViewModel();
Resetting partially loaded data will only lead to behaviour that is hard to reproduce. It is better to start with a fresh instance.
Your standard approach will be something like below
ViewModels
CustomersContainerViewModel which contains
a collection of CustomerViewModel s
and ICommands like
CreateNewCustomer
DeleteExistingCustomer
UpdateExistingCustomer
Your View will contain
the CustomersContainerView which will contain
a collection of Customer Objects in your required UI element
a button to Create new customer (which will launch a new screen which contains the newCustomer fields it can also contain cancel, which will just close the form)
a button to delete (can also be a ContextMenu)
a button to update (can also be a ContextMenu) which will launch a customer form filled with details from DB.
Hopefully this makes some sense... Let me know if you have problem with any of the above
Update - Forgot to add. NewCustomer Command will add a new Customer object to your CustomerCollection and that should open a NewCustomer form (or whatever you chose) for user to input the customer details. Cancel/Delete will just remove that record from the collection. Delete will update the DB as well in addition
In my case
yourViewName.variableName.postValue("")
I've got standard CreateNewEntity screen. Entity can contain list of entities of some other type. By default there is an add button that opens modal window when user wants to add another entity into collection. However, default modal window was lacking some of the needed functionality so I've done a bit of research. Turns out that default modal screens cannot be modified. So, I found a nice custom modal window helper class. The problem is that I can't seem to be able to access modal window fields in order to enforce needed logic. There are two dropdown lists that are associated. Change in one will result in limiting the other dropdown list options. I'm stuck at this particular part:
var proxy = this.FindControl("DodavanjeParcele");
proxy.ControlAvailable += (s, e) =>
{
var ctrl = e.Control as System.Windows.Controls.Control;
//how to obtain access to ctrl fields?
};
"DodavanjeParcele" is custom modal window. Before this, modal window is instantiated and initialized. It pops up after button click and functions as expected. The only thing missing are above-mentioned rules. I need to set change event handlers for modal window fields in order to define rules. As seen above I tried to cast IProxy as a standard Windows control. This is where I got stuck. I can't seem to find a way to access control fields and set event handlers. Any thoughts?
If I understand you correctly, I'm not sure why you need to search through controls or cast anything.
Control1 is an entity which creates an AutoComplete Box (dropdown list). That selection is copied into a local property in the Control1_Changed method. That property is used as a parameter in a filter query to create Control2.
C#:
private void Control1_Changed()
{
this.MyLocalProperty = this.Control1.SelectedItem;
}
VB.NET:
Private Sub Control1_Changed()
Me.MyLocalProperty = Me.Control1.SelectedItem
End Sub
Just make sure you have Auto Execute Query checked in Control2's Properties and the second control should update and filter when Control1 changes the query parameter.
The code in my screen shots all takes place inside of Yann's Modal Helper so there is nothing special you need to do.