I'm experiencing a strange behaviour of ActivityIndicator in my XamarinForms project. The indicator loads up perfectly in WinPhone81 but not in the middle of the layout for the first time, but it works perfectly from the second time to infinity. Below is the code I used:
In XAML:
<StackLayout x:Name="blueBar" Padding ="0,0,0,0" Orientation ="Vertical"
HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand" >
</StackLayout>
In CS:
ActivityIndicator loading = new ActivityIndicator();
blueBar.Children.Add(loading);
loading.IsRunning = true;
//some functions
blueBar.Children.Remove(loading);
Does any knows why its behaving like this ?!
Any suggestions/guide/help will be appreciated..!!
Thanks in advance.
Note: The ActivityIndicator works well and fine in Droid & iOS projects.
Output: as I'm experiencing
1.First time execution of the page:
2.Second time execution of the same page:
Output: as per -Chandresh Khambhayata
Thanks for helping me out guys...
I Finally figured out an answer for my question...
Here is the working code of mine (on all the three platforms).
XAML :
<StackLayout x:Name="blueBar" Padding="0,0,0,0" Orientation="Vertical" VerticalOptions="FillAndExpand" >
<ActivityIndicator x:Name="loading" IsRunning="true"></ActivityIndicator>
</StackLayout>
CS :
somebtn.Clicked += async(sender,e) => {
loading.IsVisible = true;
//some await functions like api call or something
loading.IsVisible = false;
}
The actual problem is., the Indicator is not allocated by InitializeComponent() before., so when I click any of the button for the first time., Indicator displays to the left of the layout.
But., now the Indicator is initialized by InitializeComponent()., and so the indicator is displaying in the middle for the first click itself...
Note : This problem only occured on windowsphone only not on ios and android projects.
Now the updated code works well and good on all the three platforms.
if you want to display ActivityIndicator in center of the screen then you most have to apply HorizontalOptions="Center" and VerticalOptions="Center"
I am using the below XML code and it's working perfect for me.
<StackLayout VerticalOptions="CenterAndExpand" HorizontalOptions="CenterAndExpand">
<ActivityIndicator Color="White" HorizontalOptions="Center" VerticalOptions="Center" />
<Label Grid.Row="1" x:Name="LabelLoading" HorizontalOptions="Center" TextColor="White" Text="Loading..." FontFamily="Droid Sans Mono" HorizontalTextAlignment="Center" VerticalTextAlignment="Center" />
</StackLayout>
Here is programmatically setting activity indicator.
ActivityIndicator activityIndecator = new ActivityIndicator();
activityIndecator.Color = Color.White;
activityIndecator.HorizontalOptions = LayoutOptions.Center;
activityIndecator.VerticalOptions = LayoutOptions.Center;
blueBar.Children.Remove(activityIndecator);
Thank You.
it seems like you need to put your StackLayout inside a AbsoluteLayout first in order for you to adjust the ActivityIndicator to the middle.
This should link help you.
Haven't tried this yet, but it looks like you need to do a lot of stuff to achieve it.
Hope it helps!
Related
Fill the TableView with so many ViewCells, so you must scroll the page to see the last ViewCell.
If you then update the last ViewCell (change the text of the label) over the Tapped-Event, the label.Text would not be updated..
PS: The ForceUpdateSize is no way the fix the solution, because on iOS the app freeze at the sixth time.
<TableView Intent="Settings" HasUnevenRows="True">
<TableRoot>
<TableSection>
<ViewCell x:Name="DefaultViewCell" Tapped="ItemTapped">
<StackLayout>
<Label x:Name="DefaultLabel" />
</StackLayout>
</ViewCell>
<!--.....-->
</TableSection>
</TableRoot>
</TableView>
I have tested your sample code , it actually happened the phenomenon your describe. Although it not happens in Android ,however it occurs in IOS .Maybe there are something difference about Label between IOS anf Android.
Finally , I found a solution in IOS. You can set a default Text Value to Label ,then Tapped method can work .
As Follow:
<TableView Intent="Settings" HasUnevenRows="True" BackgroundColor="Accent" >
<TableRoot>
<TableSection>
<ViewCell x:Name="DefaultViewCell" Tapped="DefaultViewCell_Tapped">
<StackLayout>
<Label x:Name="DefaultLabel" Text="Default Text "/>
</StackLayout>
</ViewCell>
...
</TableSection>
</TableRoot>
</TableView>
Is there any way to add background Image on navigationbar page by page on xamarin forms?
The would need to write a custom render to change the background of the navigation bar. This is simply because the navigation bar does not have an option to change the background image.
https://books.google.co.uk/books/about/Xamarin_Forms_Solutions.html?id=wvt9DwAAQBAJ&printsec=frontcover&source=kp_read_button&redir_esc=y#v=onepage&q&f=false
There's a good very brief section about how to write custom renders is this ^ book (you can even find it in the preview without purchasing it).
An alternative solution would be to create a custom banner at the top of the page
https://forums.xamarin.com/discussion/126227/customizing-navigation-bar-or-action-bar-in-xamarin-forms[As mentioned in this answer2
<ContentPage NavigationPage.HasNavigationBar="false">
<StackLayout VerticalOptions="Start"
HorizontalOptions="FillAndExpand"
Orientation="Horizontal"
Padding="10,5,10,5>
<Image HorizontalOptions="StartAndExpand" source="yourimage.png"/>
<Label HorizontalOptions="CenterAndExpand" Text="ALL"/>
<Image HorizontalOptions="EndAndExpand" source="yourimage.png"/>
</StackLayout>
<StackLayout>
<!-- Place your code for page body-->
</StackLayout>
</ContentPage>
I've copied the code into here for simplicity and reference. This solution removes the navigation bar and allows you to create a custom banner on each page in XAML. In here you can change the layout as you please.
I have a weird situation on my Xamarin.Forms app. I´m trying to show an ActivityIndicator, but it is not showing in any condition. I´ve set all conditions on XAML and then I tried on code behind. But I could not get it to work. This is the code:
<StackLayout HorizontalOptions="Center"
VerticalOptions="Center">
<ActivityIndicator x:Name="actIndicator"
Color="Blue"
IsVisible="True"
IsRunning="True"/>
<Label x:Name="lblCargando"
Text="Cargando..." />
<Label x:Name="lblStatus"/>
<Button x:Name="btnCerrar"
Text="Cerrar"
IsVisible="False"
Clicked="Cerrar_Clicked"/>
</StackLayout>
Is there something missing?.
Thanks.
Finally, it seems that there was an issue with the emulator that was executing an old version of code.
I deleted the emulator and re create it and get rid of the problem.
I am using ViewCell to create rows in my table settings page. I have a setting to select a Light or Dark theme.
<ViewCell Height="50">
<StackLayout x:Name="darkTheme" VerticalOptions="FillAndExpand" Padding="20,0,20,0">
<StackLayout Orientation="Horizontal" VerticalOptions="CenterAndExpand">
<Label Text="Dark" XAlign="Center" FontSize="15"/>
<Label x:Name="darkThemeCheckmark" Text="{x:Static local:FontAwesome.FACheck}" FontFamily="FontAwesome" XAlign="Center" IsVisible="false" FontSize="12" HorizontalOptions="EndAndExpand"/
</StackLayout>
</StackLayout>
</ViewCell>
<ViewCell Height="50">
<StackLayout x:Name="lightTheme" VerticalOptions="FillAndExpand" Padding="20,0,20,0">
<StackLayout Orientation="Horizontal" VerticalOptions="CenterAndExpand">
<Label Text="Light" XAlign="Center" FontSize="15"/>
<Label x:Name="lightThemeCheckmark" Text="{x:Static local:FontAwesome.FACheck}" FontFamily="FontAwesome" XAlign="Center" IsVisible="false" FontSize="12"/>
</StackLayout>
</StackLayout>
</ViewCell>
Whenever I switch from dark to light theme, there is faint light line on the left side between my rows that I can't seem to get rid of. Please refer to the images below:
In my renderer I have set the following:
tableView.LayoutMargins = new UIEdgeInsets() { Left = 20 };
cell.SeparatorInset = new UIEdgeInsets() { Left = 20 };
cell.LayoutMargins = new UIEdgeInsets() { Left = 20 };
Anyone knows how to get rid of this line?
Edit:
I wanted it to look like below:
I am novice to xamarin but, According to this post you need to do this on the UITableView and on your UITableViewCell subclasses.
I hope this will help you. :)
Apologies in advance incase you have already considered this but I believe what you're looking for is 'TableView.SeparatorInset' this would apply to your renderer rather than the xaml your using in your PCL. You can find the documentation around styling the tableviews at this link.
E.G.
TableView.SeparatorInset.InsetRect(new CGRect(4, 4, 150, 2));
Moving the inset of the seperator will get around the problem I saw you mention in the comments of the other answer about the whole table shifting. Please let me know if you've tried this already, it's the simplest solution but there are other options available to you. (They just aren't as nice).
Edit: Example of a way of achieving your goals by creating your own seperators, not my favourite but would also resolve the issue you've highlighted as you'd have complete control over the styling of a seperator. Refer to this Link
I am trying to display data using carousel view in my forms application. I am not sure what am I missing but data is not getting populated, I have followed almost all available samples but still I have not found any success. Please help me get out of this problem:
I am using the following code in my xaml file:
<forms:CarouselView x:Name="listview" ItemsSource="postIdList" HeightRequest="200" Margin="5">
<forms:CarouselView.ItemTemplate>
<DataTemplate>
<ContentPage >
<StackLayout >
<Label Text="{Binding .}" FontSize="20" TextColor="Black" HorizontalOptions="Center" />
</StackLayout>
</ContentPage>
</DataTemplate>
</forms:CarouselView.ItemTemplate>
</forms:CarouselView>
And I am trying to populate the data in the following manner in .cs file:
List<string> postIdList = new List<string>
{
"Carousel", "Carousel", "carousel"
};
listview.ItemsSource = postIdList;
If I give a background colour for carousal view I am able to see that colour, but text is not getting displayed.
Please let me know my mistake.
In case of a ListView, you need an ObservableCollection instead of a List. Switch it around and see if it works?
On your XAML you are defining a <ContentPage> inside the <Datatemplate>. Replace the <ContentPage> with a <ViewCell> or a <Grid>
Here is a great example on how to use it, you need to keep in mind that CarouselView work like a ListView, it need to have a Datatemplate.