小编yan*_*ify的帖子

我正在尝试使用3个组件创建自定义选取器.我在这里关注了Xamarin网站上的教程.我让控件工作,除非我点击选择器上的完成按钮(这是默认的完成按钮).我得到以下异常:

System.InvalidCastException:无法将类型为'myproj.iOS.MyPickerModel'的对象强制转换为'Xamarin.Forms.Platform.iOS.PickerRenderer + PickerSource'.

这是我的代码:

在共享项目中:

public class MyPicker: Picker {}

在iOS项目中:

[assembly: ExportRenderer(typeof(MyPicker), typeof(MyPickerRenderer))]

public class MyPickerRenderer: PickerRenderer
{
    // Override the OnElementChanged method so we can tweak this renderer post-initial setup
    protected override void OnElementChanged(ElementChangedEventArgs<Picker> e)
    {
        base.OnElementChanged(e);

        if (Control != null)
        {   
            var picker = (UIPickerView)this.Control.InputView;
            picker.BackgroundColor = UIColor.White;
            picker.Model = new MyPickerModel();
        }

而型号:

public class MyPickerModel : UIPickerViewModel
{
    private string[] array1  = new string [] {
        "1","2","3","4"
    };
    private string[] array2  = …