我正在使用Xamarin.Forms创建跨平台应用程序,我的所有ContentPages都位于PCL中.
我正在寻找一种方法来设置和锁定单个ContentPage到Landscape的方向,最好不必在每个特定于平台的项目中创建另一个活动.
由于我的ContentPage.Content设置为ScrollView,我尝试将ScrollOrientation设置为Horizontal,但是这不起作用.
我也尝试过使用RelativeLayout,但我在这上面看不到Orientation属性.
public class PlanningBoardView : ContentPage //Container Class.
{
public PlanningBoardView()
{
scroller = new ScrollView ();
Board = new PlanningBoard();
scroller.Orientation = ScrollOrientation.Horizontal;
scroller.WidthRequest = Board.BoardWidth;
scroller.Content = Board;
Content = scroller;
}
}
我尝试的最后一件事是使用Xamarin Studio的Intellisense版本和Xamarin Forms API Doc’s来查看我可用的不同布局,其中没有一个具有Orientation属性.
我担心唯一的方法是为这个ContentPage创建第二个特定于平台的Activity,并将方向设置为landscape.
虽然这种方法可行,但它使屏幕之间的导航变得更加复杂.
目前正在Android中测试.
解决方法
讨厌这样说,但这只能使用
custom renderers或特定于平台的代码来完成
在android中,您可以将MainActivity的RequestedOrientation属性设置为ScreenOrientation.Landscape.
在iOS中,当Xamarin.Forms.Application.Current.MainPage是您所在的ContentPage时,您可以覆盖AppDelegate类中的GetSupportedInterfaceOrientations以返回其中一个UIInterfaceOrientationMask值.
Android的
[assembly: Xamarin.Forms.ExportRenderer(typeof(MyCustomContentPage),typeof(CustomContentPageRenderer))]
public class CustomContentPageRenderer : Xamarin.Forms.Platform.Android.PageRenderer
{
private ScreenOrientation _prevIoUsOrientation = ScreenOrientation.Unspecified;
protected override void OnWindowVisibilityChanged(ViewStates visibility)
{
base.OnWindowVisibilityChanged(visibility);
var activity = (Activity)Context;
if (visibility == ViewStates.Gone)
{
// Revert to prevIoUs orientation
activity.RequestedOrientation = _prevIoUsOrientation == ScreenOrientation.Unspecified ? ScreenOrientation.Portrait : _prevIoUsOrientation;
}
else if (visibility == ViewStates.Visible)
{
if (_prevIoUsOrientation == ScreenOrientation.Unspecified)
{
_prevIoUsOrientation = activity.RequestedOrientation;
}
activity.RequestedOrientation = ScreenOrientation.Landscape;
}
}
}
iOS版
public partial class AppDelegate : global::Xamarin.Forms.Platform.iOS.FormsApplicationDelegate
{
public override UIInterfaceOrientationMask GetSupportedInterfaceOrientations(UIApplication application,UIWindow forWindow)
{
if (Xamarin.Forms.Application.Current == null || Xamarin.Forms.Application.Current.MainPage == null)
{
return UIInterfaceOrientationMask.Portrait;
}
var mainPage = Xamarin.Forms.Application.Current.MainPage;
if (mainPage is MyCustomContentPage ||
(mainPage is NavigationPage && ((NavigationPage)mainPage).CurrentPage is MyCustomContentPage) ||
(mainPage.Navigation != null && mainPage.Navigation.ModalStack.LastOrDefault() is MyCustomContentPage))
{
return UIInterfaceOrientationMask.Landscape;
}
return UIInterfaceOrientationMask.Portrait;
}
}
