I have this problem: I can send data or a value to a function from a page or an API but razer component doesn't show the value; actually, it doesn't render new values.
Here's my example function:
public string p="";
public void myMethod(string a)
{
p=a;
}
Here's my HTML tag:
<p>#p</p>
When I click the button from an other page, myMethod will be called like this:
private void buttonClick()
{
new NavMenu().myMethod("Test text");
}
The button click is in a page and NavMenu is a component. I debug this and the value of 'p' successfully changed but the page does not show new value.
Actually I tried this code but nothing happened:
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(p));
What should I do to display new values without refreshing the page?
Related
I have an Android application with a dialog and a few buttons inside.
I want to reuse the dialog for different purposes and looking for a way to call the button from a separate class and define an action event for it.
Creating a test class, I managed to define an action event for a button inside a form, but the same code does not work for a button inside a dialog, and I can't get my head around why it is not working for the dialog.
Below is what I already have. Any suggestions would be appreciated.
public Class One {
Test test = new Test();
test.testOne(); // this is working : button prints
test.testTwo(); // this is not working : button does not print
buttonTest = test.getTestButton();
buttonTest.setText("Hello World"); // not working for a button in a dialog
buttonTest.addActionListener(l-> { // prints when the button in a Form
System.out.println("try"); // does not print when the button is in a dialog
});
}
public class Test {
Dialog dialog = new Dialog();
Form form = new Form();
Button button;
public void testOne() {
button = new Button("Test");
form.add(button);
form.show();
}
public void testTwo() {
button = new Button("Testing");
dialog.add(button);
dialog.show();
}
public Button getTestButton () {
return button;
}
}
You add the action listener after showing the form and dialog. This isn't a problem for the form since the forms show method will continue. But a dialogs show() method will block.
Two solutions:
Move the listener binding higher in the code (before the show) that would be a problem since the button doesn't exist yet so you will need some refactoring.
Change the show() call on the dialog to showModless()
In my application there are several drop-down boxes each mapped with ValueChangeListner so when any value changes from the drop-down, the ValueChangeEvent was fired and searches for all the methods in the controller layer who takes ValueChangeEvent as an argument.
This is how I initialize the drop-down for which I am getting error
private void methodForDropDown1(){
bean.setValue(null);
List<String> datas=new ArrayList<>();
datas.add("val1");
datas.add("val2");
datas.add("val3");
List<SelectItem> tableData = buildSelectionItems(datas);//takes String and returns SelectItem
datas.setComboBox(tableData);
}
This is how I am handling the ValueChangeEvent
public void comboBoxDropDown1(ValueChangeEvent event) {
if(event.getOldValue()==null){
return;
}
try {
if (event.getNewValue()!=null) {
process event
}
Problem with me that if after server start at the first time if I click on any other drop-down box then the drop-down I have mentioned here, was initialized and event.getNewValue() -> val1,
but if I click on the drop-down then it is not taking the event.getOldValue() it is showing null.
in the page by default it shows val1 when the page was loaded, so by assuming that, this is the new value if I select val2/val3 then it is taking these values as getNewValue() but as expected it is not taking va1 as getOldValue().
I'm using Windows Azure Mobile Services to store and retrieve data in my Windows Phone 8 app. This is a bit of a complicated issue so I will do my best to explain it.
Firstly I'm using raw push notifications to receive a message and when it receives the message it updates a listbox in my app. When I open my app, navigate to the page with the ListBox and receive a push notification the ListBox updates fine. If I press back, then navigate to the same page with the ListBox, the push notification is received, the code to update the ListBox executes with no errors yet the ListBox doesn't update. I have checked that the same code runs using the OnNavigatedTo handler in both scenarios, but it seems like the ListBox does not bind correctly in the second instance when I press back and then re-navigate to the same page. Here are some code snippets:
MobileServiceCollection declarations:
public class TodoItem
{
public int Id { get; set; }
[JsonProperty(PropertyName = "text")]
public string Text { get; set; }
}
private MobileServiceCollection<ToDoItem, ToDoItem> TodoItems;
private IMobileServiceTable<TodoItem> todoTable = App.MobileService.GetTable<TodoItem>();
Push Notification Received Handler:
void PushChannel_HttpNotificationReceived(object sender, HttpNotificationEventArgs e)
{
string message;
using (System.IO.StreamReader reader = new System.IO.StreamReader(e.Notification.Body))
{
message = reader.ReadToEnd();
}
Dispatcher.BeginInvoke(() =>
{
var todoItem = new TodoItem
{
Text = message,
};
ToDoItems.Add(todoItem);
}
);
}
I have tried using:
ListItems.UpdateLayout();
and
ListItems.ItemsSource = null;
ListItems.ItemsSource = ToDoItems;
before and after the code in the above procedure that adds the ToDoItem but it didn't help.
The following procedure is called in my OnNavigatedTo event handler, and refreshes the Listbox and assigns ToDoItems as the items source:
private async void RefreshTodoItems()
{
try
{
ToDoItems = await todoTable
.ToCollectionAsync();
}
catch (MobileServiceInvalidOperationException e)
{
MessageBox.Show(e.Message, "Error loading items", MessageBoxButton.OK);
}
ListItems.ItemsSource = ToDoItems;
}
The above procedure is async but I have made sure it completes before receiving any notifications. Even so, as mentioned above when I open the app, navigate to the page that shows the ListBox it updates fine. When I press back, navigate to the same page again, it doesn't work. When I back out of the app, re-open it, navigate to the page with the ListBox, it works again, and then fails if I press back and re-open the page. So it seems the ListBox is not binding to ToDoItems correctly when I press back and navigate to the same page.
Any help appreciated. Thanks.
Can you modify your approach a bit to use Data Binding and the MVVM model to bind your model to your view.
It might look like a bit of effort initially but will save you a lot of debugging hours later on.
Just follow the below steps
Create a new class that implements INotifyPropertyChanged
Add the below method implementation
public event PropertyChangedEventHandler PropertyChanged;
private void NotifyPropertyChanged(String propertyName)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (null != handler)
{
handler(this, new PropertyChangedEventArgs(propertyName));
}
}
Add public ObservableCollection<TodoItem> TodoItems{ get; private set; } and initialize it in the constructor.
Every PhoneApplicationPage has a DataContext member. Assing it to a singleton instance of the above class that you create.
In the XAML, add the property ItemsSource="{Binding TodoItems}" to the list.
In the DataTemplate of the list use ItemsSource="{Binding Text}" for the control you wish to display this value on. ( e.g. TextBlock )
Now whenever you add elements to the collection, it will be reflected in the UI, and vice-versa.
I want to invoke the keyListener and get the keyCode while the dialog is being shown. I have tried extending Dialog and overrided the keyReleased() with no success. Below is my code, what went wrong?
public class MyDialog extends Dialog{
public void keyReleased(int keyCode) {
super.keyReleased(keyCode); //To change body of generated methods, choose Tools | Templates.
System.out.println("Keycode in Dialog: "+keyCode);
}
}
And in my form, I am using the custom Dialog like below:-
MyDialog dialog = new MyDialog();
dialog.show("INFO", "TEST CONTENT", "OK", "CANCEL");
You aren't using your dialog.
show(String, String, String, String) is a static method not an instance method so a new dialog instance is created and shown.
You need to use show() which is an instance method (or some other instance method like showDialog), but then you will have to actually add the components and "construct" your dialog.
i call this method SolveUpdation (from button- onclickAction Listener) from mainAcitivity with main layout. i use other layout to get value from user and set it as button title in the main layout and that is only instruction that does not works for me
private void SolveUpdation() { //this function call is generated from the main Activity with main layout
setContentView(R.layout.updateappliance); //this is 2nd layout to get values from user and use them as buttonText in the main layout
btnSaveApp = (Button) findViewById(R.id.Bupdatenow);
btnSaveApp.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
mOutEditText = (EditText) findViewById(R.id.edit_text_1);
TextView view1 = (TextView) findViewById(R.id.edit_text_1);
final String TitleApp1 = view1.getText().toString(); //the value is read properly here
// if (App1.length() > 0) {
// byte[] send = App1.getBytes();
// }
btnSaveApp.setText(TitleApp1); //this works fine
startActivity(new Intent(HomeScreen.this, HomeScreen.class));//this the main activity for main layout
setContentView(R.layout.main); //this is the main layout and this instruction works
buttonLED1.setText(TitleApp1); //buttonLED1 (a Togglebutton or can be simple) is defined in main layout and this does not works and this is what i am stuck with
SaveAppNamesToast(TitleApp1); //this is just to toast the value and it works fine.
}});
So plz can any one guide me why this instruction buttonLED1.setText(TitleApp1); does not works ??? Any help will be appreciatable.. thanks
No offense, but the way you write your code is not a good practice.
My advise: Stop calling another setContentView in your Main Activity. You should rather implement all needed Buttons and EditTexts in one layout and set their visiblity to gone or visible depending on which button was clicked.
If you don't wanna do this you should create a second class that handles the input of the user. After pressing the save button you initialize your intent for the main activity and give it via intent.putExtra("KEY", value) the input of the user.
Your Main Activity can receive this value via getIntent().getExtras().getInt("KEY").
By the way: I think your current code doesn't work because of the new Activity you start. Through this everything gets initialized again so the buttonLED1 that you see isn't the same buttonLED1 that gets the text.