Xamarin.iOS 中的选取器可用 [英] Picker in Xamarin.iOS available

问题描述

iOS Picker 在 Xamarin.iOS 中是否可用?我已经搜索过，但既没有例子也没有资料；但是，它在 Xamarin.Form 中可用.

解决方案

将 UIPickerView 添加到名为 slotMachineView 的 xib 或 Storyboard:

使用系统；使用 UIKit；命名空间插槽{公共部分类 ViewController : UIViewController{public ViewController (IntPtr handle) : base (handle){}公共覆盖 void ViewDidLoad(){base.ViewDidLoad();slotMachineView.Model = new StackOverflowModel (selectedLbl);}公共覆盖无效 DidReceiveMemoryWarning(){base.DidReceiveMemoryWarning();}}公共类 StackOverflowModel : UIPickerViewModel{静态字符串 [] 名称 = 新字符串 [] {"pscorlib.dll","pscorlib_aot.dll","Mono.PlayScript.dll","PlayScript.Dynamic.dll","PlayScript.Dynamic_aot.dll","PlayScript.Optimization.dll","playshell.exe",psc.exe"};UILabel lbl;公共 StackOverflowModel (UILabel lbl){this.lbl = lbl;}公共覆盖 nint GetComponentCount (UIPickerView v){返回3；}公共覆盖 nint GetRowsInComponent (UIPickerView pickerView, nint 组件){返回名称.长度；}公共覆盖字符串 GetTitle(UIPickerView 选择器、nint 行、nint 组件){开关(组件){案例0:返回名称 [行];情况1:返回行.ToString();案例2:返回新字符串 ((char)('A' + row), 1);默认:抛出新的NotImplementedException();}}公共覆盖无效选定(UIPickerView 选择器，nint 行，nint 组件){lbl.Text = String.Format ("{0} : {1} : {2}",名称 [picker.SelectedRowInComponent (0)],picker.SelectedRowInComponent (1),picker.SelectedRowInComponent (2));}公共覆盖 nfloat GetComponentWidth(UIPickerView 选择器，nint 组件){如果(组件== 0)返回 220f；别的返回 30f；}}}

Is iOS Picker available in the Xamarin.iOS? I have searched throughly but there is neither example nor information has been founded; however, it is available in Xamarin.Form.

解决方案

A real quickie example of a UIPickerView: (iOS SDK)

Add a UIPickerView to your xib or Storyboard called slotMachineView:

using System;
using UIKit;

namespace Slots
{
    public partial class ViewController : UIViewController
    {
        public ViewController (IntPtr handle) : base (handle)
        {
        }

        public override void ViewDidLoad ()
        {
            base.ViewDidLoad ();
                slotMachineView.Model = new StackOverflowModel (selectedLbl);
        }

        public override void DidReceiveMemoryWarning ()
        {
            base.DidReceiveMemoryWarning ();
        }
    }

    public class StackOverflowModel : UIPickerViewModel
    {
        static string[] names = new string [] {
            "pscorlib.dll",
            "pscorlib_aot.dll",
            "Mono.PlayScript.dll",
            "PlayScript.Dynamic.dll",
            "PlayScript.Dynamic_aot.dll",
            "PlayScript.Optimization.dll",
            "playshell.exe",
            "psc.exe"
        };

        UILabel lbl;

        public StackOverflowModel (UILabel lbl)
        {
            this.lbl = lbl;
        }

        public override nint GetComponentCount (UIPickerView v)
        {
            return 3;
        }

        public override nint GetRowsInComponent (UIPickerView pickerView, nint component)
        {
            return names.Length;
        }

        public override string GetTitle (UIPickerView picker, nint row, nint component)
        {
            switch (component) {
            case 0:
                return names [row];
            case 1:
                return row.ToString ();
            case 2:
                return new string ((char)('A' + row), 1);
            default:
                throw new NotImplementedException ();
            }
        }

        public override void Selected (UIPickerView picker, nint row, nint component)
        {
            lbl.Text = String.Format ("{0} : {1} : {2}",
                names [picker.SelectedRowInComponent (0)],
                picker.SelectedRowInComponent (1),
                picker.SelectedRowInComponent (2));
        }

        public override nfloat GetComponentWidth (UIPickerView picker, nint component)
        {
            if (component == 0)
                return 220f;
            else
                return 30f;
        }
    }
}

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