xamarin.forms

问题 I'm trying to load "png's" into a ListView in a XamarinForms app using Android and UWP projects. Here is my xaml of the ListView. <ListView x:Name="TemplateListView" ItemsSource="{Binding TemplateData}"> <ListView.ItemTemplate> <DataTemplate> <StackLayout Orientation="Vertical"> <Image Margin="20,0,0,0" Source="{Binding ImageData}" Aspect="AspectFit" HeightRequest="120"></Image> <Label Text="{Binding Title}" FontSize="16" /> </StackLayout> </DataTemplate> </ListView.ItemTemplate> </ListView>

问题 I'm trying to initialize a CLLocationCoordinate2D class in a iOS custom render that i have, and in the constructor i can pass a Latitude and Longitude (double, double) as parameters to initialize it, but whatever the values i give, the class always comes with the default double value for the Latitude and Longitude. (0,0) , here is how i tried to initialize it at first: CLLocationCoordinate2D iosCoords = new CLLocationCoordinate2D(38.00000000000000, -9.00000000000000); //This inits has (0,0) /

问题 I'm trying to initialize a CLLocationCoordinate2D class in a iOS custom render that i have, and in the constructor i can pass a Latitude and Longitude (double, double) as parameters to initialize it, but whatever the values i give, the class always comes with the default double value for the Latitude and Longitude. (0,0) , here is how i tried to initialize it at first: CLLocationCoordinate2D iosCoords = new CLLocationCoordinate2D(38.00000000000000, -9.00000000000000); //This inits has (0,0) /

问题 I am using Xamarin.forms.Maps for showing the map in my project. The map is inside the ListView and I need to bind the coordinate positions to the map. Model Class: public class History { public double Latitude { get; set; } public double Longitude { get; set; } } Data adding part: historyList.Add(new History() { Latitude= -28.854930 ,Longitude= 151.166023 }); historyList.Add(new History() { Latitude = -28.853671, Longitude = 151.165712 }); historyList.Add(new History() { Latitude = -28

问题 If I add an item to a listview, the items is added but the image is not showed. I have to restart application to view it. The Item is correctly added but the image is not visible. here the cs. ObservableCollection<Libreria> items = new ObservableCollection<Libreria>(new Libreria().GetLibrerie()); public Home() { InitializeComponent (); lstLibrerie.ItemsSource = items; //pickerLibrerie.ItemsSource = new Libreria().GetLibrerie(); } public void Reload(Libreria newLib) { items.Insert(0, newLib);

问题 I have a one picker and I have one Firebase Database. And I wanna add data my picker. How can I add data from my firebase database in a picker in my Xamarin form ? 来源： https://stackoverflow.com/questions/63684808/xamarin-picker-add-data-from-firebase

问题 So I create a standard xamarin form project with a default template, then I add a Master Detail page template to the project and when I compile this project on the phone I open the side menu and when I click on Page 1 I get the error "System.InvalidCastException: Specified cast is not valid. " I do not change the default template in any way, but I get an error, I believe that it is related to the transition to Page 1 and I do not understand by what principle this transition occurs. Thanks.

问题 I'm working on an application in Xamarin.Forms and I try to use nearby Wi-Fi signals for indoor tracking. But it is not possible because of Android Wi-Fi Throttling. How can I disable it, event my Huawei P20 Pro does not have this option in Developer Menu? Can be another options to scan efficiently Wi-Fi signals on Android or is not possible as long as Wi-Fi Throttling can't be controlled? 回答1: According to wifi-scan-throttling docs, Android 10 has the Wi-Fi Throttling option in Developer

问题 I am using the HttpClient but my results are taking up to 6 seconds coming back from the same machine on the same subnet and ip range of 192.168. When I call the api directly from the ip address the results are more or less instant so why is it so slow with httpclient on the same computer. I have seen other so's that suggest set to use proxy as false is the best way to go. I have also tested this on a stock phone and it takes around 8 seconds for the login to be successful on the phone.

问题 I work on a Xamarin.Forms app that will contain a page with 2 CollectionView items: an horizontal CollectionView that will display events a vertical CollectionView that will display posts I would like that the first list is progressively hidden as soon as the user starts to scroll on the second list. We can found this behaviour on a sample from Syncfusion : but they use a SfRotator as control for the horizontal list: I've tried to reproduce the same behaviour on my page, but it doesn't work