I have a list of news, when a news is clicked it sends the user to a new page with the specific newsitem.
On the news item page I want to manipulate the object sent so I can change values within this object.
My ItemTappedEvent looks like this
public void goToEvent(object sender, ItemTappedEventArgs e)
{
if (e.Item == null)
{
return;
}
var selectedItem = e.Item; // model
Navigation.PushAsync(new eventItem(selectedItem)); // pass the selected whole item from list to DetaiPage 'selectedItem' using constructor
((ListView)sender).SelectedItem = null;
}
My NewsItem page handles this as a c# object like this
public eventItem(object selectedItem)
{
this.BindingContext = selectedItem;
InitializeComponent();
}
Within my "selectedItem" is a value named "product_wheelchair"
If this has the value "true"
Do I wan't to change it to "Ja". How can i convert my object "selectedItem" so this is possible.
Thanks in advance!
You need to cast the object to your class like:
var mySelectedItem = selectedItem as myClass
After that you can access the properties/fields available in myClass. Obviously if those are private you need to make them public to be accessible.
Related
If I have for example one master view on the left and one in the middle, each showing oder Java Beans/POJOs, can I use a shared detail view that somehow listens to the active beans of each view and then displays the currently selected one in more detail? A one to one relation is quite easy to manage by using your Context library.
#ViewDocking(areaId ="left", position=1, displayName="Profiles", menuEntry = #WindowMenuEntry(path = "", position=0), accelerator="Shortcut+1")
public class ProfileListView extends BorderPane implements LocalContextProvider {
private final SimpleContextContent content = new SimpleContextContent();
private final SimpleContext context = new SimpleContext(content);
#FXML
private ListView<Profile> listview;
public ProfileListView() {
load();
// add some profiles
listview.getItems().add(new Profile("Profile1"));
listview.getItems().add(new Profile("Profile2"));
listview.getItems().add(new Profile("Profile3"));
// setup selection listener
listview.getSelectionModel().selectedItemProperty().addListener((value, oldProfile, newProfile) -> {
// set active profile and remove old one
content.remove(oldProfile);
content.add(newProfile);
});
// setup double click listener
configureClickListener();
}
private Profile getSelectedProfile() {
return listview.getSelectionModel().getSelectedItem();
}
private void configureClickListener() {
listview.setOnMouseClicked(event -> {
// check if it was a double click
if(event.getClickCount() == 2) {
System.out.println(getSelectedProfile());
// inject into editor pane
// calls the procedure to create a tab in the center area...
}
});
}
private void load() {
FXMLLoaders.loadRoot(this);
}
#Override
public Context getLocalContext() {
return context;
}
}
This is one master view holding a list view of items.
The other one would be the same, docking to the right as another tab and holding POJOs of type 'Action'.
The detail view is here:
#ViewDocking(areaId = "right", displayName = "Properties", accelerator = "Shortcut+2", menuEntry = #WindowMenuEntry(path = "", position = 0), position = 1)
public class ProfilePropertiesView extends BorderPane implements LocalContextProvider, ActiveContextSensitive {
private Context activeContext;
private SimpleContextContent content = new SimpleContextContent();
private SimpleContext context = new SimpleContext(content);
private Profile profile;
private IWindowService service = new NullWindowService();
#FXML
private PropertySheet propertysheet;
public ProfilePropertiesView() {
load();
// retrieve framework service, TODO: use tracker
BundleContext ctx = FrameworkUtil.getBundle(getClass()).getBundleContext();
service = ctx.getService(ctx.getServiceReference(IWindowService.class));
// initialize callback
service.addCallback(title -> {
System.out.println("callback called " + title);
// update the property sheet ui by re-creating the items list
// updateUI();
// we can safely return null
return null;
});
// configure editor factory so the user is able to use a combobox
propertysheet.setPropertyEditorFactory(new CustomPropertyEditorFactory(service));
}
private void load() {
FXMLLoaders.loadRoot(this);
}
#Override
public Context getLocalContext() {
return context;
}
private void contextChanged() {
// find profile information
Profile found = activeContext.find(Profile.class);
// if the found profile is null, ignore it
if (found != null) {
// reset if profile is valid
if (profile != null) {
reset();
}
// create reference and register
profile = found;
register();
}
}
private void register() {
// retrieve observablelist of bean properties if some profile is selected
if(profile != null) {
ObservableList<Item> items = createDetailedList(profile);
propertysheet.getItems().setAll(items);
}
}
private void updateUI() {
// clear property elements and re-create them
reset();
// re-create items
ObservableList<Item> items = createDetailedList(profile);
propertysheet.getItems().addAll(items);
}
private ObservableList<Item> createDetailedList(Object bean) {
ObservableList<Item> list = FXCollections.observableArrayList();
try {
BeanInfo beanInfo = Introspector.getBeanInfo(bean.getClass(), Object.class);
Arrays.stream(beanInfo.getPropertyDescriptors()).map(pd -> new DetailedBeanProperty(bean, pd)).forEach(list::add);
} catch (IntrospectionException e) {
e.printStackTrace();
}
return list;
}
private void reset() {
propertysheet.getItems().clear();
}
#Override
public void setActiveContext(Context activeContext) {
this.activeContext = activeContext;
this.activeContext.addContextListener(Profile.class, event -> contextChanged());
// trigger change
contextChanged();
}
}
The current ProfilePropertiesView is just configured to display the properties of the selected profile. I want it to be able to display the current information of the last selected POJO in the UI. That means that if the user selected a Profile from the ListView, that profile should be displayed in the properties view. If he selected an Action from the Table (which is displayed in the center), the properties of the Action should be displayed.
Do I just need to register a new ContextListener for the Action.class
POJO and then call a method to populate the PropertiesView? I was
unsure if this is the right solution...
Yes, just add another ContextListener to the activeContext for every POJO type you want to observe.
Also note that in the constructor of views it's better to use a ServiceTracker instead of looking for the service via BundleContext as the service might not be available yet, depending on the order the bundles are loaded.
You can find a sample which uses a ServiceTracker here: https://stackoverflow.com/a/35974498/506855
I'm making a Windows Store App that asks for user input then produces a bunch of pushpins based on that input. When a pushpin is tapped the app navigates to a page with more detail.
Now the problem i'm having is this:
My pages all inherit from the automatically generated LayoutAwarePage so I could potentially make use of SaveState and LoadState to save the pushpins so they don't get wiped on navigation. The thing is that i can't get the pins to save into the Dictionary object supplied by SaveState.
The error I get is "Value cannot be null" and it's referring to the _pageKey variable in LayoutAwarePage.OnNavigatedFrom() and i don't know why it's happening.
I've tried serialising them into a JSON string so i can deserialise it in LoadState, but i get the same result using a string or a List of UIelement.
I think this is all due to my lack of understanding of how SaveState, LayoutAwarePAge and SuspensionManager work. I thought what i was doing would work as the Dictionary is only asking for a string and an object.
I'm not using any other methods from LayoutAwarePage so if there is a better way than using SaveState and LoadState, I'm all ears.
These are the two versions of SaveState i've tried:
Using JSON
protected override void SaveState(Dictionary<String, Object> pageState)
{
List<string> pindata = new List<string>();
List<string> serialisedpins = new List<string>();
foreach (Pushpin ele in map.Children)
{
pindata = ele.Tag as List<string>;
serialisedpins.Add(JsonConvert.SerializeObject(pindata));
}
string jasoned = JsonConvert.SerializeObject(serialisedpins);
pageState["pins"] = jasoned;
}
using a List of UIElement
protected override void SaveState(Dictionary<String, Object> pageState)
{
List<UIElement> pins = new List<UIElement>(map.Children);
pageState["pins"] = pins;
}
The error you're getting (_pagekey value cannot be null) is not really related to what you're saving into the Dictionary. The exception is most likely being thrown in OnNavigateFrom() method of LayoutAwarePage:
protected override void OnNavigatedFrom(NavigationEventArgs e)
{
var frameState = SuspensionManager.SessionStateForFrame(this.Frame);
var pageState = new Dictionary<String, Object>();
this.SaveState(pageState);
frameState[_pageKey] = pageState; // <-- throws exception because _pageKey is null
}
If you take a look at the rest of the code of LayoutAwarePage you'll find out the value of _pageKey is being set in OnNavigatedTo method of LayoutAwarePage:
protected override void OnNavigatedTo(NavigationEventArgs e)
{
// Returning to a cached page through navigation shouldn't trigger state loading
if (this._pageKey != null) return;
var frameState = SuspensionManager.SessionStateForFrame(this.Frame);
this._pageKey = "Page-" + this.Frame.BackStackDepth; <-- this line sets the _pageKey value
if (e.NavigationMode == NavigationMode.New)
{
// Clear existing state for forward navigation when adding a new page to the
// navigation stack
var nextPageKey = this._pageKey;
int nextPageIndex = this.Frame.BackStackDepth;
while (frameState.Remove(nextPageKey))
{
nextPageIndex++;
nextPageKey = "Page-" + nextPageIndex;
}
// Pass the navigation parameter to the new page
this.LoadState(e.Parameter, null);
}
else
{
// Pass the navigation parameter and preserved page state to the page, using
// the same strategy for loading suspended state and recreating pages discarded
// from cache
this.LoadState(e.Parameter, (Dictionary<String, Object>)frameState[this._pageKey]);
}
}
Usually the reason for that is that you're overriding OnNavigatedTo in your own page without calling base.OnNavigatedTo(e) inside it. The basic pattern of overriding it should always be:
protected override void OnNavigatedTo(NavigationEventArgs e)
{
base.OnNavigatedTo(e);
// the rest of your own code
}
This will make sure the base implementation will execute and set the _pageKey value as well as call LoadState() to load the previously saved state if there's any.
In XAML and WinRT, Is there a way to set up a textbox so that it is disabled for text input until it is tapped.
I tried setting up the Tapped event and then setting the IsEnabled=true, but that only seems to work if the IsEnabled=true in the first place.
I found this on MSDN:
http://social.msdn.microsoft.com/Forums/en-US/winappswithcsharp/thread/708c0949-8b06-40ec-85fd-201139ca8b2d
Talks about adding the TappedEvent manually to the event handled for each TextBox, which is cumbersome, but also doesn't seem to work unless IsEnabled was already set to true.
Basically, I want a form where all textboxes display data but are disabled unless the user taps to enable the box and then type.
You can use IsReadOnly instead of IsEnabled to achieve what you are looking for. In addition, you can set up the tapped event handlers in code easily. I'm not sure if setting up handlers in code is a requirement for this to work, as you noted above; however, it does simplify things.
Here are the details.
In the constructor of your page class (here it is MainPage), call the setup function:
public MainPage()
{
this.InitializeComponent();
// call the setup for the textboxes
SetupTextBoxes();
}
Here is where we do the magic - make all textboxes on this page readonly and set up tap handler:
private void SetupTextBoxes()
{
var tbs = GetVisualChildren<TextBox>(this, true);
foreach (var tb in tbs)
{
tb.IsReadOnly = true;
tb.AddHandler(TappedEvent, new TappedEventHandler(tb_Tapped), true);
}
}
Utility function to get a list of all children of the given type (T) of the passed in parent.
private List<T> GetVisualChildren<T>(DependencyObject parent, bool recurse = true)
where T : DependencyObject
{
var children = new List<T>();
int numVisuals = VisualTreeHelper.GetChildrenCount(parent);
for (int i = 0; i < numVisuals; i++)
{
DependencyObject v = (DependencyObject)VisualTreeHelper.GetChild(parent, i);
var child = v as T;
if (child == null && recurse)
{
var myChildren = GetVisualChildren<T>(v, recurse);
children.AddRange(myChildren);
}
if (child != null)
children.Add(child);
}
return children;
}
Finally, the event handler. This enables each textbox when tapped.
private void tb_Tapped(object sender, TappedRoutedEventArgs e)
{
((TextBox)(sender)).IsReadOnly = false;
}
I have two view and their corresponding ViewModels and i want to send text from one view to another using MVVM Light as follows
in first viewmodel i am calling the following method
public void NavigatePage()
{
string temp = "temp value";
Messenger.Default.Send("temp");
Frame frame = Window.Current.Content as Frame;
if (frame != null) frame.Navigate(typeof(MyPage), temp);
}
while in page 2 view model i am having the following code
public MyViewModel()
{
Messenger.Default.Register<string>(this, MessageReceived);
}
private string test;
public string Test
{
get { return test; }
set { test = value; RaisePropertyChanged("Test");}
}
private void MessageReceived(string message)
{
Test = message;
}
when i debug my code the ctor of this viewmodel is getting called but the MessageReceived is not getting called hence property Test is never getting set, I am missing something, please help
Is the SecondViewModel actually created before you send the message? You can specify this in the ViewModelLocator class.
In the locator you have to register your viewmodel and CREATE it when the applications starts.
Like this:
SimpleIoc.Default.Register<SecondViewModel>(true);
With the true parameter the SecondViewModel will be created when the application is started! :)
I've been working towards a solution for some time and could use a little help. I know I've seen an example of this before, but tonight I cannot find anything close to what I need.
I have a service that provides me all my DropDownLists, either from Cache or from the DomainService. They are presented as IEnumerable, and are requested from the a repository with GetLookup(LookupId).
I have created a custom attribute that I have decorated my MetaDataClass that looks something like this:
[Lookup(Lookup.Products)]
public Guid ProductId
I have created a custom Data Form that is set to AutoGenerateFields and I am intercepting the autogenerate fields.
I am checking for my CustomAttribute and that works.
Given this code in my CustomDataForm (standard comments removed for brevity), what is the next step to override the field generation and place a bound combobox in its place?
public class CustomDataForm : DataForm
{
private Dictionary<string, DataField> fields = new Dictionary<string, DataField>();
public Dictionary<string, DataField> Fields
{
get { return this.fields; }
}
protected override void OnAutoGeneratingField(DataFormAutoGeneratingFieldEventArgs e)
{
PropertyInfo propertyInfo = this.CurrentItem.GetType().GetProperty(e.PropertyName);
foreach (Attribute attribute in propertyInfo.GetCustomAttributes(true))
{
LookupFieldAttribute lookupFieldAttribute = attribute as LookupFieldAttribute;
if (lookupFieldAttribute != null)
{
// Create a combo box.
// Bind it to my Lookup IEnumerable
// Set the selected item to my Field's Value
// Set the binding two way
}
}
this.fields[e.PropertyName] = e.Field;
base.OnAutoGeneratingField(e);
}
}
Any cited working examples for SL4/VS2010 would be appreciated.
Thanks
Update - Here's where I am at. I get my combo now, but it's always empty even though itemsSource is not.
if (lookupFieldAttribute != null)
{
ComboBox comboBox = new ComboBox();
Binding newBinding = e.Field.Content.GetBindingExpression(TextBox.TextProperty).ParentBinding.CreateCopy();
newBinding.Mode = BindingMode.TwoWay;
newBinding.Converter = new LookupConverter(lookupRepository);
newBinding.ConverterParameter = lookupFieldAttribute.Lookup.ToString();
comboBox.SetBinding(ComboBox.SelectedItemProperty,newBinding);
comboBox.ItemsSource = lookupRepository.GetLookup(lookupFieldAttribute.Lookup);
e.Field.Content = comboBox;
}
I found a solution.
if (lookupFieldAttribute != null)
{
ComboBox comboBox = new ComboBox();
Binding newBinding = e.Field.Content.GetBindingExpression(TextBox.TextProperty).ParentBinding.CreateCopy();
var itemsSource = lookupRepository.GetLookup(lookupFieldAttribute.Lookup);
var itemsSourceBinding = new Binding { Source = itemsSource };
comboBox.SetBinding(ItemsControl.ItemsSourceProperty, itemsSourceBinding);
newBinding.Mode = BindingMode.TwoWay;
newBinding.Converter = new LookupConverter(lookupRepository);
newBinding.ConverterParameter = lookupFieldAttribute.Lookup.ToString();
comboBox.SetBinding(ComboBox.SelectedItemProperty,newBinding);
e.Field.Content = comboBox;
}