为啥我的 UIPickerView 在选择时崩溃

Posted 2023-02-24

【中文标题】为啥我的 UIPickerView 在选择时崩溃

【英文标题】：Why does my UIPickerView crashing when selecting为什么我的 UIPickerView 在选择时崩溃

【发布时间】：2012-05-24 19:45:52

【问题描述】：

我在github上创建了一个示例Github link

当点击一行或试图在 UIPickerView 中滚动时，它会崩溃，我想知道为什么。

// create a ActionSheet
var actionPickerSheet = new UIActionSheet("Select a Category");
actionPickerSheet.Style = UIActionSheetStyle.BlackTranslucent;
// Create UIpickerView
var catPicker = new UIPickerView()
    Model = new catPickerModel(),
    AutosizesSubviews = true,
    Hidden = false,
    ShowSelectionIndicator = true
;
// show inside view and add the catPicker as subView
actionPickerSheet.ShowInView(View);
actionPickerSheet.AddSubview(catPicker);
// resize both views so it fits smoothly
actionPickerSheet.Frame = new RectangleF(0,100,320,500);
catPicker.Frame = new RectangleF(actionPickerSheet.Frame.X,actionPickerSheet.Frame.Y-25,actionPickerSheet.Frame.Width, 216);

还有模特

private class catPickerModel : UIPickerViewModel

    public string[] protocolNames = new string[]
    
        "Web", "Phone Call", "Google Maps", "SMS", "Email"
    ;

    public override int GetComponentCount(UIPickerView uipv)
    
        return 1;
    

    public override int GetRowsInComponent( UIPickerView uipv, int comp)
    
        //each component has its own count.
        int rows = protocolNames.Length;
        return(rows);
    

    public override string GetTitle(UIPickerView uipv, int row, int comp)
      
        //each component would get its own title.
        return protocolNames[row];
    

    public override void Selected(UIPickerView uipv, int row, int comp)
    
        Console.WriteLine("selected:" + row);
    

    public override float GetComponentWidth(UIPickerView uipv, int comp)
    
        return 300f;
    

我不知道为什么它总是崩溃，是我在模型中缺少某种方法还是我试图以错误的方式做到这一点？

谢谢

【问题讨论】：

请添加一些有关崩溃本身的信息，例如堆栈跟踪。

【参考方案1】：

尝试将您的catPicker 设为类的私有变量：

namespace TextfieldUIPickerView

    public partial class TextfieldUIPickerViewViewController : UIViewController
    
        private UIPickerView catPicker;
 ...

看起来 GC 已经收集并处理了你的 catPicker。