I have some processes and activity indicators. When these processes are finished, I want these activity fields to disappear but not sure how to do it. All I can do is to cancel them but that doesn't make them go away. Any ideas ?
Remove the activity indicator field from the parent manager.
public static void removeField(Field f) {
Manager m = f.getManager();
if(m != null) {
m.delete(f);
}
}
Related
I am newbie to Xamarin.Forms and stuck with a situation where I want to open up a popup box with my control details [e.g. View Employee Details] on click of parent page.
How can I open custom dialog box / popup using Xamarin.Forms?
Any example code will be appreciated?
Thanks in advance!
If you still want to have your popup's code in its own Page you can set up some custom renderers along the following logic.
1. A ModalPage & corresponding renderer
public class ModalPage : ContentPage { }
public class ModalPageRenderer : PageRenderer {
protected override void OnElementChanged(VisualElementChangedEventArgs e)
{
base.OnElementChanged(e);
this.View.BackgroundColor = UIColor.Clear;
this.ModalPresentationStyle = UIModalPresentationStyle.OverCurrentContext;
}
public override void ViewDidLayoutSubviews()
{
base.ViewDidLayoutSubviews();
SetElementSize (new Size (View.Bounds.Width, View.Bounds.Height));
}
}
2. HostPage
public class ModalHostPage : ContentPage, IModalHost
{
#region IModalHost implementation
public Task DisplayPageModal(Page page)
{
var displayEvent = DisplayPageModalRequested;
Task completion = null;
if (displayEvent != null)
{
var eventArgs = new DisplayPageModalRequestedEventArgs(page);
displayEvent(this, eventArgs);
completion = eventArgs.DisplayingPageTask;
}
// If there is no task, just create a new completed one
return completion ?? Task.FromResult<object>(null);
}
#endregion
public event EventHandler<DisplayPageModalRequestedEventArgs> DisplayPageModalRequested;
public sealed class DisplayPageModalRequestedEventArgs : EventArgs
{
public Task DisplayingPageTask { get; set;}
public Page PageToDisplay { get; }
public DisplayPageModalRequestedEventArgs(Page modalPage)
{
PageToDisplay = modalPage;
}
}
}
3. HostPage renderer
public class ModalHostPageRenderer: PageRenderer
{
protected override void OnElementChanged(VisualElementChangedEventArgs e)
{
base.OnElementChanged(e);
if(e.OldElement as ModalHostPage != null)
{
var hostPage = (ModalHostPage)e.OldElement;
hostPage.DisplayPageModalRequested -= OnDisplayPageModalRequested;
}
if (e.NewElement as ModalHostPage != null)
{
var hostPage = (ModalHostPage)e.NewElement;
hostPage.DisplayPageModalRequested += OnDisplayPageModalRequested;
}
}
void OnDisplayPageModalRequested(object sender, ModalHostPage.DisplayPageModalRequestedEventArgs e)
{
e.PageToDisplay.Parent = this.Element;
var renderer = RendererFactory.GetRenderer (e.PageToDisplay);
e.DisplayingPageTask = this.PresentViewControllerAsync(renderer.ViewController, true);
}
}
Then it is as simple as calling
await ModalHost.DisplayPageModal(new PopUpPage());
from your host page or in this particular case from the ViewModel behind.
What Pete said about PushModalAsync / PopModalAsync still remains valid for this solution too (which in my opinion is not a disadvantage), but your popup would appear with transparent background.
The main advantage of this approach, in my opinion, is that you can have your popup XAML/code definition separate from the host page and reuse it on any other page where you wish to show that popup.
The general purpose of what you are trying to achieve can be accomplished by using the PushModalAsync and PopModalAsync methods of Xamarin.Forms Navigation object.
The chances are that this is good enough for what you are needing - However - this isn't truely modal. I will explain after a small code snippet:-
StackLayout objStackLayout = new StackLayout()
{
};
//
Button cmdButton_LaunchModalPage = new Button();
cmdButton_LaunchModalPage.Text = "Launch Modal Window";
objStackLayout.Children.Add(cmdButton_LaunchModalPage);
//
cmdButton_LaunchModalPage.Clicked += (async (o2, e2) =>
{
ContentPage objModalPage = new ContentPage();
objModalPage.Content = await CreatePageContent_Page2();
//
await Navigation.PushModalAsync(objModalPage);
//
// Code will get executed immediately here before the page is dismissed above.
});
//
return objStackLayout;
private async Task<StackLayout> CreatePageContent_Page2()
{
StackLayout objStackLayout = new StackLayout()
{
};
//
Button cmdButton_CloseModalPage = new Button();
cmdButton_CloseModalPage.Text = "Close";
objStackLayout.Children.Add(cmdButton_CloseModalPage);
//
cmdButton_CloseModalPage.Clicked += ((o2, e2) =>
{
this.Navigation.PopModalAsync();
});
//
return objStackLayout;
}
The problem with the above is that the
await Navigation.PushModalAsync(objModalPage);
will immediately return after the animation.
Although you can't interact with the previous page, as we are displaying a new NavigationPage with a Close button shown - the parent Navigation Page is still executing behind the scenes in parallel.
So if you had any timers or anything executing these still would get called unless you stopped those.
You could also use the TaskCompletionSource approach as outlined in the following post also How can I await modal form dismissal using Xamarin.Forms?.
Note - that although you can now await the 2nd page displaying and then when that page is dismissed allowing code execution to continue on the next line - this is still not truely a modal form. Again timers or anything executing still will get called on the parent page.
Update 1:-
To have the content appear over the top of existing content then simply include it on the current page, however make this section of content invisible until you need it.
If you use an outer container such like a Grid that supports multiple child controls in the same cell, then you will be able to achieve what you want.
You will also want to use something like a filled Box with transparency that will cover the entire page also, to control the visible, see through section, that surrounds your inner content section.
I followed above approach and found it impossible to run on iOS 7.
I found this library BTProgressHUD which you can modify and use.
I Use its methods by Dependency service.
Actual library for popups.
https://github.com/nicwise/BTProgressHUD
Following example uses BTProgressHUD library internally.
https://github.com/xximjasonxx/ScorePredictForms
Hello all i stuck at one problem. I have implemented a ListField in one Screen. On top of the Screen i have used one HorizontalFieldManager to hold a TitleLabel and Two Butons. I have pushed some screen on all the rows of the listfield. My problem is, letSuppose when i am on 4th row and i have selected what i want then when i clicking on the button, then the button worked but the screen which i have implemented at 4th row also appear how to avoid it. I am testing it on storm 9550 simulator and using Blackberry eclipse plugin5.0 . I am running out of idea please help me .
navigation click is like this
protected boolean navigationClick(int status, int time) {
selectListAndButton();
return true;
}
//And here is the selectListAndButton Method
private selectListAndButton(){
Field field = getFieldWithFocus().getLeafFieldWithFocus();
if(field == backCustomButton){
//Popped the active Screen
}else if(field == saveCustomButton){
//Saving some Data to the Database And pushing another Screen here
// problem comes here if i am at 2nd row of the listfield and selects
something from there and clicked on the button the screen which was
implemented at 2nd row also appears
}
else if (_list.getSelectedIndex() == 0){
//Called a date picker
}
else if (_list.getSelectedIndex() == 1){
//Pushed some another screen
}
else if (_list.getSelectedIndex() == ){
//Pushed some another screen
}
You need to override onTouch for Screen and call specific functionality depend on event coordinates and Field boundaries:
protected boolean touchEvent(TouchEvent message) {
if (isTouchInside(message, saveCustomButton)) {
save();
} else {
showNextScreen();
}
}
private boolean isTouchInside(TouchEvent messages, Field field) {
int eventCode = message.getEvent();
int touchX = message.getX(1);
int touchY = message.getY(1);
XYRect rect = field.getContentRect();
return rect.contains(touchX, touchY);
}
I had solved it. but posting the answer late. I just dropped the idea of using ListField because i dont have so much rows to add. So i have just used the little trick rather using ListField i have used HorizontalFieldManager and its look like a List so everything working fine.
Thanks cheers :)
I have 3 buttons A, B and C. When I click A, the page reloads and the focus will be on A and when I click B, the page reloads and focus will be on B and so on. How do I implement this?
if(constants.focuz.equals("next")){
next.setFocus();
}else if (constants.focuz.equals("prev")){
prev.setFocus();
} else{
abtme.setFocus();
}
Your code is Ok. You probably call it on a non-UI thread? If yes, then use UiApplication.invokeLater(Runnable action) to reset the focus. So it should be something like this:
UiApplication.getUiApplication.invokeLater(new Runnable() {
public void run() {
if (constants.focuz.equals("next")) {
next.setFocus();
} else if (constants.focuz.equals("prev")) {
prev.setFocus();
} else {
abtme.setFocus();
}
}
});
To set focus for the button field you have to use
setFocus() method.
Example code:
ButtonField lf=new ButtonField("Button");
lf.setFocus();
Hope this will help you
My app has has an option to show screen-B instead of screen-A (default main) at app start up.
First I tried pushScreen(screen-B) in screen-A's constructor which resulted in display stack has screen-A on top and then screen-B..
What I want to do is:
At start up if the option is on, show screen-B (stack has screen-B then screen-A so that Escape key would lead to screen-A)
What would be the right way to acheive this?
You might consider pushing B a little bit later in the process, in the onUiEngineAttached method:
class ScreenA extends Screen {
...
protected void onUiEngineAttached(boolean attached) {
if (attached) {
// check condition and push B as appropriate
}
}
}
When the application starts, in the UiApplication class make the following:
class UiApp extends UiApplication {
UiApp() {
if (yourCondition)
//start A
else
//start B
}
public static void main (String[] args) {
UiApp app = new UiApp();
app.enterEventDispatcher();
}
}
In my BlackBerry application, I have a home screen. The user can then navigate to a settings screen. When the user goes back to the home screen, is there no method that is called on the home screen indicating that the screen has come to the foreground?
I have tried onFocus() with no avail.
Thanks!
Unfortunately, hooking on the onExposed is not enough. I found that in Blackberry dialogs are also screens and even context menus are screens too. They are pushed on top of your screen so you receive onExposed callback when they are dismissed.
Though it's OK in many cases, in other cases it poses a problem - e.g. if I must refresh the screen's content only when the user returns to it, but not after menus/dialogs, then how do I do that? My case is, unfortunately, one of those.
I found no documented way of detecting "covered"/"uncovered" events. Here is my approach. onCovered/onUncovered callbacks are called when the current screen is covered/uncovered by another screen of the app, but not by dialogs/menus/virtual keyboard:
public class MyAppScreen extends MainScreen {
private boolean isCovered;
protected void onExposed() {
Log.d("onExposed");
super.onExposed();
if (isCovered) {
onUncovered();
isCovered = false;
}
}
protected void onObscured() {
Log.d("onObscured");
super.onObscured();
final Screen above = getScreenAbove();
if (above != null) {
if (isMyAppScreen(above)) {
isCovered = true;
onCovered();
}
}
}
private boolean isMyAppScreen(final Screen above) {
return (above instanceof MyAppScreen);
}
protected void onUncovered() {
Log.d("onUncovered");
}
protected void onCovered() {
Log.d("onCovered");
}
protected void onUiEngineAttached(final boolean attached) {
if (attached) {
Log.d("UI Engine ATTACHED");
} else {
Log.d("UI Engine DETACHED");
}
super.onUiEngineAttached(attached);
}
protected void onFocusNotify(final boolean focus) {
if(focus){
Log.d("focus GAINED");
} else {
Log.d("focus LOST");
}
super.onFocusNotify(focus);
}
}
And a test. Try various combinations and see what events you receive in the log.
public class TestLifecycle extends MyAppScreen implements FieldChangeListener {
private final ABNTextEdit txt1;
private final ButtonField btn1;
private final ButtonField btn2;
public TestLifecycle() {
final Manager manager = getMainManager();
txt1 = new ABNTextEdit();
manager.add(txt1);
btn1 = new ButtonField("Dialog", ButtonField.CONSUME_CLICK);
btn1.setChangeListener(this);
manager.add(btn1);
btn2 = new ButtonField("Screen", ButtonField.CONSUME_CLICK);
btn2.setChangeListener(this);
manager.add(btn2);
}
public void fieldChanged(final Field field, final int context) {
if (field == btn1) {
Dialog.alert("Example alert");
} else if (field == btn2) {
UiApplication.getUiApplication().pushScreen(new TestLifecycle());
}
}
}
Update:
This method has a limitation: if a new screen is pushed when a dialog or the soft keyboard has focus your current screen will not receive onCovered/onUncovered notification.
Example A: if you have an input field of fixed size and you push a new screen when the user completes it, your current screen will not receive the notification if the user types very quickly. This happens because in the moment between you call push(newScreen) and it is actually pushed the user clicks on a letter on soft KB and it grabs the focus. So only onObscured is called, but not onCovered.
Solution: explicitly hide the soft keyboard before the push(newScreen).
Example B: if you have a customized dialog which pushes new screen and then dismisses itself, your current screen will not receive the notification. This happens because your customized dialog is not recognized as a screen, so only onObscured is called, but not onCovered.
Solution: dismiss the dialog in the first place returning a result value, and let your screen push the new screen based on that value. -OR- override isMyAppScreen() to return true also for your customized dialog.
You should be able to use protected void onExposed() to detect when it is displayed again.