Ambiguous reference between 'Xamarin.Forms.Label' an

我开始我的第一个Xamarin。

我的启动项目是firstApp.Droid。

在MainActivity.cs在firstApp。Droid我有这个代码:

namespace firstApp.Droid
{
    [Activity (Label = "firstApp", Icon = "@drawable/icon", MainLauncher = true, ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation)]
    public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsApplicationActivity
    {
        protected override void OnCreate (Bundle bundle)
        {
            base.OnCreate (bundle);
            global::Xamarin.Forms.Forms.Init (this, bundle);
            LoadApplication (new firstApp.App ());
        }
    }
}

在App.cs我有这个代码:

public App ()
    {
        // The root page of your application
        MainPage = new NavigationPage(new SensorPage());
    }

在SensorPage.cs我有这个自动生成的代码:

public class SensorPage : ContentPage
{
    public SensorPage ()
    {
        Content = new StackLayout {
            Children = {
                new Label { Text = "Hello SensorPage" } //line that causes the error
            }
        };
    }
}

当我尝试编译应用程序时，我得到错误:

CS0104 'Label'是在'Xamarin.Forms. '之间的一个模糊引用。标签'和'System.Reflection.Emit.Label'

我该怎么做才能解决这个问题?

Content = new StackLayout {
            Children = {
                new Xamarin.Forms.Label { Text = "Hello SensorPage" }
            }
        };