我想通过点击工具栏按钮来拉伸我的地图。 我成功就是去了另一个页面（MapFullPage）。
问题是我希望通过App.Current.Main = new MainMasterDetailPage(new MapPage())覆盖BackButtonPressed时它会让我失望，但我的缩放不是更理想的缩放（当我离开此页面并继续使用MapFullPage时） ，缩放很小（我可以看到大陆）。
如果我拨打App.Current.Main = new MapPage()，则会显示正确的缩放。
这是我的两个班级： MapPage - ＆gt;
public class MapPage : ContentPageCustom
{
//TKCustomMap mapView;
//TKCustomMapPin pinSelected;
DealerLocationResponseModel responseLocations;
DealerLocationResponseModel responseShops;
DealerLocationResponseModel responseStats;
DealerLocationResponseModel responseMoney;
public MapPage()
{
try
{
if (IsBusy)
return;
IsBusy = true;
this.CreateView();
}
catch (Exception ex)
{
DisplayAlert("Error", Constants.StandardError, "OK");
}
finally
{
IsBusy = false;
}
}
private async void CreateView()
{
try
{
Icon = "map-alt.png";
Title = "Locations";
var mapView = new TKCustomMap();
mapView.IsShowingUser = true;
mapView.SetBinding(TKCustomMap.CustomPinsProperty, "Pins");
mapView.SetBinding(TKCustomMap.MapClickedCommandProperty, "MapClickedCommand");
mapView.SetBinding(TKCustomMap.MapLongPressCommandProperty, "MapLongPressCommand");
mapView.SetBinding(TKCustomMap.MapCenterProperty, "MapCenter");
mapView.SetBinding(TKCustomMap.PinSelectedCommandProperty, "PinSelectedCommand");
mapView.SetBinding(TKCustomMap.SelectedPinProperty, "SelectedPin");
mapView.SetBinding(TKCustomMap.RoutesProperty, "Routes");
mapView.SetBinding(TKCustomMap.PinDragEndCommandProperty, "DragEndCommand");
mapView.SetBinding(TKCustomMap.CirclesProperty, "Circles");
mapView.SetBinding(TKCustomMap.CalloutClickedCommandProperty, "CalloutClickedCommand");
mapView.SetBinding(TKCustomMap.PolylinesProperty, "Lines");
mapView.SetBinding(TKCustomMap.PolygonsProperty, "Polygons");
mapView.SetBinding(TKCustomMap.MapRegionProperty, "MapRegion");
mapView.SetBinding(TKCustomMap.RouteClickedCommandProperty, "RouteClickedCommand");
mapView.SetBinding(TKCustomMap.RouteCalculationFinishedCommandProperty, "RouteCalculationFinishedCommand");
mapView.SetBinding(TKCustomMap.TilesUrlOptionsProperty, "TilesUrlOptions");
mapView.SetBinding(TKCustomMap.MapFunctionsProperty, "MapFunctions");
mapView.IsRegionChangeAnimated = true;
NavigationPage.SetHasBackButton(this, false);
BackgroundColor = Color.White;
responseLocations = ServiceProvider.GetDealerLocationServiceMethod(new DealerLocationRequestModel { MobilePhoneNumber = "063333333", UserIdentificator = "1234" });
if (!responseLocations.Succeeded)
{
await DisplayAlert("Greska", "Nije nadjena nijedna lokacija", "OK");
App.Current.MainPage = new HomeMasterDetail();
return;
}
List<TKCustomMapPin> pinLists = new List<TKCustomMapPin>();
foreach (var item in responseLocations.Dealers)
{
pinLists.Add(
new TKCustomMapPin
{
Image = "_mapPin_36x36",
IsCalloutClickable = true,
ShowCallout = true,
Position = new Position(item.Latitude, item.Longitude),
Title = item.LocationName + " " + item.Address,
Subtitle = item.LocationDescription
}
);
}
mapView.CustomPins = pinLists;
#region Stack and Buttons
mapView = new TKCustomMap(MapSpan.FromCenterAndRadius(mapView.CustomPins.ElementAt(1).Position, Distance.FromKilometers(2)));
mapView.CustomPins = new List<TKCustomMapPin>(pinLists);
mapView.IsShowingUser = true;
StackLayout btnCart = ElementsHelper.createImageButton("_cart_512x512.png", "Shops");
StackLayout btnStats = ElementsHelper.createImageButton("_stats_512x512.png", "Top up");
StackLayout btnMoney = ElementsHelper.createImageButton("_money_512x512.png", "Cash out");
StackLayout layout = new StackLayout
{
Orientation = StackOrientation.Horizontal,
HorizontalOptions = LayoutOptions.Center,
Children =
{
btnStats,
btnMoney,
btnCart
}
};
BoxView box1 = new BoxView { BackgroundColor = Color.Transparent, HeightRequest = Device.GetNamedSize(NamedSize.Large, typeof(Image)) * 2.5, WidthRequest = Device.GetNamedSize(NamedSize.Large, typeof(Image)) * 2.5 };
BoxView box2 = new BoxView { BackgroundColor = Color.Transparent, HeightRequest = Device.GetNamedSize(NamedSize.Large, typeof(Image)) * 2.5, WidthRequest = Device.GetNamedSize(NamedSize.Large, typeof(Image)) * 2.5 };
ActivityIndicator activityIndicator = new ActivityIndicator();
activityIndicator.Color = Constants.iPink;
activityIndicator.BindingContext = this;
activityIndicator.IsRunning = true;
activityIndicator.HeightRequest = 70;
activityIndicator.Margin = new Thickness(15, 0);
activityIndicator.SetBinding(ActivityIndicator.IsRunningProperty, "IsBusy");
activityIndicator.SetBinding(ActivityIndicator.IsVisibleProperty, "IsBusy");
layout.Children.Add(activityIndicator);
StackLayout layoutIndicator = new StackLayout { Orientation = StackOrientation.Horizontal };
layoutIndicator.Children.Add(box1);
layoutIndicator.Children.Add(activityIndicator);
layoutIndicator.Children.Add(box2);
layoutIndicator.IsVisible = false;
TapGestureRecognizer btnShopRecognizer = new TapGestureRecognizer();
btnShopRecognizer.Tapped += async (sender, e) =>
{
if (IsBusy)
return;
IsBusy = true;
layout.IsVisible = false;
layoutIndicator.IsVisible = true;
await Task.Delay(400);
responseShops = ServiceProvider.GetDealerLocationServiceMethod(new DealerLocationRequestModel { MobilePhoneNumber = "063333333", UserIdentificator = "1234" }, 1);
SetPins(mapView, responseShops);
mapView.MoveToRegion(MapSpan.FromCenterAndRadius(new Position(responseShops.Dealers.ElementAt(1).Latitude, responseShops.Dealers.ElementAt(1).Longitude), Distance.FromKilometers(2)));
SetActiveButtonMap(btnCart, btnStats, btnMoney);
IsBusy = false;
layoutIndicator.IsVisible = false;
layout.IsVisible = true;
};
TapGestureRecognizer btnMoneyRecognizer = new TapGestureRecognizer();
btnMoneyRecognizer.Tapped += async (sender, e) =>
{
if (IsBusy)
return;
IsBusy = true;
layout.IsVisible = false;
layoutIndicator.IsVisible = true;
await Task.Delay(400);
responseMoney = ServiceProvider.GetDealerLocationServiceMethod(new DealerLocationRequestModel { MobilePhoneNumber = "063333333", UserIdentificator = "1234" }, 2);
SetPins(mapView, responseMoney);
mapView.MoveToRegion(MapSpan.FromCenterAndRadius(new Position(responseMoney.Dealers.ElementAt(1).Latitude, responseMoney.Dealers.ElementAt(1).Longitude), Distance.FromKilometers(2)));
SetActiveButtonMap(btnMoney, btnStats, btnCart);
IsBusy = false;
layoutIndicator.IsVisible = false;
layout.IsVisible = true;
};
TapGestureRecognizer btnStatsRecognizer = new TapGestureRecognizer();
btnStatsRecognizer.Tapped += async (sender, e) =>
{
if (IsBusy)
return;
IsBusy = true;
layout.IsVisible = false;
layoutIndicator.IsVisible = true;
await Task.Delay(400);
responseStats = ServiceProvider.GetDealerLocationServiceMethod(new DealerLocationRequestModel { MobilePhoneNumber = "063333333", UserIdentificator = "1234" }, 3);
SetPins(mapView, responseStats);
mapView.MoveToRegion(MapSpan.FromCenterAndRadius(new Position(responseStats.Dealers.ElementAt(1).Latitude, responseStats.Dealers.ElementAt(1).Longitude), Distance.FromKilometers(2)));
SetActiveButtonMap(btnStats, btnMoney, btnCart);
IsBusy = false;
layoutIndicator.IsVisible = false;
layout.IsVisible = true;
};
btnCart.GestureRecognizers.Add(btnShopRecognizer);
btnMoney.GestureRecognizers.Add(btnMoneyRecognizer);
btnStats.GestureRecognizers.Add(btnStatsRecognizer);
#endregion
RelativeLayout _baseLayout = new RelativeLayout { VerticalOptions = LayoutOptions.FillAndExpand };
_baseLayout.Children.Add(
mapView,
Constraint.RelativeToParent((parent) =>
{
return (0);
}),
Constraint.RelativeToParent((parent) =>
{
return (0);
}),
heightConstraint: Constraint.RelativeToParent((r) => r.Height),
widthConstraint: Constraint.RelativeToParent((r) => r.Width));
Func<RelativeLayout, double> getLayoutWidth = (p) => layout.Measure(_baseLayout.Width, _baseLayout.Height).Request.Width;
_baseLayout.Children.Add(layout,
Constraint.RelativeToParent((parent) => parent.Width / 2 - getLayoutWidth(parent) / 2),
Constraint.RelativeToParent((parent) =>
{
return (.8 * parent.Height);
})
);
_baseLayout.Children.Add(layoutIndicator,
Constraint.RelativeToParent((parent) => parent.Width / 2 - getLayoutWidth(parent) / 2),
Constraint.RelativeToParent((parent) =>
{
return (.8 * parent.Height);
})
);
//_baseLayout.Children.Add(activityIndicator,
//Constraint.RelativeToParent((parent) => parent.Width / 2),
//Constraint.RelativeToParent((parent) =>
//{
// return (.8 * parent.Height);
//})
//);
Constraint.RelativeToParent((parent) =>
{
return (1);
});
_baseLayout.HeightRequest = App.ScreenHeight - 200;
Content = _baseLayout;
}
catch
{
await DisplayAlert("Error", Constants.StandardError, "OK");
}
//this._baseLayout.Children.Add(
// mapView,
// Constraint.RelativeToView(autoComplete, (r, v) => v.X),
// Constraint.RelativeToView(autoComplete, (r, v) => autoComplete.HeightOfSearchBar),
// heightConstraint: Constraint.RelativeToParent((r) => r.Height - autoComplete.HeightOfSearchBar),
// widthConstraint: Constraint.RelativeToView(autoComplete, (r, v) => v.Width));
//this._baseLayout.Children.Add(
// autoComplete,
// Constraint.Constant(0),
// Constraint.Constant(0));
}
private void SetPins(TKCustomMap map, DealerLocationResponseModel dealerModel = null)
{
List<TKCustomMapPin> pinLists = new List<TKCustomMapPin>();
foreach (var item in dealerModel.Dealers)
{
pinLists.Add(
new TKCustomMapPin
{
Image = "_mapPin_36x36",
IsCalloutClickable = true,
ShowCallout = true,
Position = new Position(item.Latitude, item.Longitude),
Title = item.LocationName + " " + item.Address,
Subtitle = item.LocationDescription,
}
);
}
//map.CustomPins = null;
map.CustomPins = pinLists;
}
private void SetActiveButtonMap(StackLayout activeImage, StackLayout disabledImage1, StackLayout disabledImage2)
{
var a = ((activeImage.Children[0] as Image).Source as FileImageSource).File;
if ((!((activeImage.Children[0] as Image).Source as FileImageSource).File.ToString().Contains("_active")))
//Set active image
StartClickCustom(activeImage.Children[0] as Image);
//Remove active images
if (((disabledImage1.Children[0] as Image).Source as FileImageSource).File.ToString().Contains("_active"))
{
EndClickCustom(disabledImage1.Children[0] as Image);
}
if (((disabledImage2.Children[0] as Image).Source as FileImageSource).File.ToString().Contains("_active"))
{
EndClickCustom(disabledImage2.Children[0] as Image);
}
}
}
和MapFullPage是相同的（复制/粘贴）只有onBack方法：
protected override bool OnBackButtonPressed()
{
App.fromBack = true;
App.Current.MainPage = new MainMasterDetailPage(new MapPage());
return true;
}