c# - 在 WinForms 中对一组单选按钮进行数据绑定的最佳方法

Question

我目前正在对我现有的一些 Windows 窗体进行数据绑定，并且遇到了一个问题，我无法确定在组框中对一组单选按钮控件进行数据绑定的正确方法。

我的业务对象有一个整数属性，我想对 4 个单选按钮进行数据绑定（其中每个单选按钮代表值 0 - 3）。

我目前正在绑定一个演示者对象，该对象充当表单和业务对象之间的绑定器，我现在完成它的方式是拥有 4 个单独的属性，每个属性都绑定到这些值中的每一个（我确实使用 INotifyPropertyChanged ，但不包括这里）：

Private int _propValue;

Public bool PropIsValue0 
{ 
  get { return _propValue == 0; }
  set
  {
    if (value) 
      _propValue = 0;
  }
}

Public bool PropIsValue1 { // As above, but with value == 1 }
Public bool PropIsValue2 { // As above, but with value == 2 }
Public bool PropIsValue3 { // As above, but with value == 3 }

然后我将每个单选按钮绑定到它们各自的属性，如上所述。

这对我来说似乎不正确，因此非常感谢任何建议。

score 26 · Accepted Answer

以下是本着 ArielBH 建议的精神的通用 RadioGroupBox 实现（一些代码从 Jay Andrew Allen 的RadioPanel 借用）。只需将 RadioButtons 添加到其中，将它们的标签设置为不同的整数并绑定到“Selected”属性。

public class RadioGroupBox : GroupBox
{
    public event EventHandler SelectedChanged = delegate { };

    int _selected;
    public int Selected
    {
        get
        {
            return _selected;
        }
        set
        {
            int val = 0;
            var radioButton = this.Controls.OfType<RadioButton>()
                .FirstOrDefault(radio =>
                    radio.Tag != null 
                   && int.TryParse(radio.Tag.ToString(), out val) && val == value);

            if (radioButton != null)
            {
                radioButton.Checked = true;
                _selected = val;
            }
        }
    }

    protected override void OnControlAdded(ControlEventArgs e)
    {
        base.OnControlAdded(e);

        var radioButton = e.Control as RadioButton;
        if (radioButton != null)
            radioButton.CheckedChanged += radioButton_CheckedChanged;
    }

    void radioButton_CheckedChanged(object sender, EventArgs e)
    {
        var radio = (RadioButton)sender;
        int val = 0;
        if (radio.Checked && radio.Tag != null 
             && int.TryParse(radio.Tag.ToString(), out val))
        {
            _selected = val;
            SelectedChanged(this, new EventArgs());
        }
    }
}

请注意，由于 InitializeComponent 中的初始化顺序问题，您无法通过设计器绑定到“Selected”属性（绑定是在初始化单选按钮之前执行的，因此它们的标记在第一个分配中为空）。所以像这样绑定自己：

    public Form1()
    {
        InitializeComponent();
        //Assuming selected1 and selected2 are defined as integer application settings
        radioGroup1.DataBindings.Add("Selected", Properties.Settings.Default, "selected1");
        radioGroup2.DataBindings.Add("Selected", Properties.Settings.Default, "selected2");
    }

score 5 · Accepted Answer

我知道这篇文章很旧，但是在寻找同样问题的答案时，我遇到了这篇文章，但它并没有解决我的问题。就在一分钟前，我最终有一个灯泡随机熄灭，并想分享我的解决方案。

我在一个组框中有三个单选按钮。我使用自定义类对象的 List<> 作为数据源。

类对象：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace BAL
{
class ProductItem
{

    // Global Variable to store the value of which radio button should be checked
    private int glbTaxStatus;
    // Public variable to set initial value passed from 
    // database query and get value to save to database
    public int TaxStatus
    {
        get { return glbTaxStatus; }
        set { glbTaxStatus = value; }
    }

    // Get/Set for 1st Radio button
    public bool Resale
    {
        // If the Global Variable = 1 return true, else return false
        get
        {
            if (glbTaxStatus.Equals(1))
            {
                return true;
            }
            else
            {
                return false;
            }
        }

        // If the value being passed in = 1 set the Global Variable = 1, else do nothing
        set
        {
            if (value.Equals(true))
            {
                glbTaxStatus = 1;
            }
        }
    }

    // Get/Set for 2nd Radio button
    public bool NeverTax
    {
        // If the Global Variable = 2 return true, else return false
        get
        {
            if (glbTaxStatus.Equals(2))
            {
                return true;
            }
            else
            {
                return false;
            }
        }

        // If the value being passed in = 2 set the Global Variable = 2, else do nothing
        set
        {
            if (value.Equals(true))
            {
                glbTaxStatus = 2;
            }
        }
    }

    // Get/Set for 3rd Radio button
    public bool AlwaysTax
    {
        // If the Global Variable = 3 return true, else return false
        get
        {
            if (glbTaxStatus.Equals(3))
            {
                return true;
            }
            else
            {
                return false;
            }
        }

        // If the value being passed in = 3 set the Global Variable = 3, else do nothing
        set
        {
            if (value.Equals(true))
            {
                glbTaxStatus = 3;
            }
        }
    }

// More code ...

三个单独的公共变量，get/set 访问同一个全局变量。

在后面的代码中，我有一个在 Page_Load() 设置所有控件数据绑定期间调用的函数。对于每个单选按钮，我添加了自己的数据。

radResale.DataBindings.Add("Checked", glbProductList, "Resale", true, DataSourceUpdateMode.OnPropertyChanged, false);
radNeverTax.DataBindings.Add("Checked", glbProductList, "NeverTax", true, DataSourceUpdateMode.OnPropertyChanged, false);
radAlwaysTax.DataBindings.Add("Checked", glbProductList, "Always", true, DataSourceUpdateMode.OnPropertyChanged, false);

我希望这可以帮助别人！！

score 2 · Accepted Answer

我想我会使用我自己的 GroupBox。我会将 CustomGroupBox 绑定到您的模型并从绑定值设置正确的 RadioButton（使用标签或名称属性）。

score 1 · Accepted Answer

这是我将单选按钮列表绑定到枚举的方法。

在按钮的 Tag 属性中使用 Enum 作为字符串，我使用Binding.Format和Binding.Parse事件来决定应该检查哪个按钮。

public enum OptionEnum
{
   Option1 = 0,
   Option2
}

OptionEnum _rbEnum = OptionEnum.Option1;
OptionEnum PropertyRBEnum
{
    get { return _rbEnum; }
    set
    {
        _rbEnum = value;
        RaisePropertyChanged("PropertyRBEnum");
    }
}

public static void FormatSelectedEnum<T>(object sender, ConvertEventArgs args) where T : struct
{
    Binding binding = (sender as Binding);
    if (binding == null) return;

    Control button = binding.Control;

    if (button == null || args.DesiredType != typeof(Boolean)) return;

    T value = (T)args.Value;
    T controlValue;

    if (Enum.TryParse(button.Tag.ToString(), out controlValue))
    {
        args.Value = value.Equals(controlValue);
    }
    else
    {
        Exception ex = new Exception("String not found in Enum");
        ex.Data.Add("Tag", button.Tag);

        throw ex;
    }
}

public static void ParseSelectedEnum<T>(object sender, ConvertEventArgs args) where T : struct
{
    Binding binding = (sender as Binding);
    if (binding == null) return;

    Control button = binding.Control;
    bool value = (bool)args.Value;

    if (button == null || value != true) return;

    T controlValue;

    if (Enum.TryParse(button.Tag.ToString(), out controlValue))
    {
        args.Value = controlValue;
    }
    else
    {
        Exception ex = new Exception("String not found in Enum");
        ex.Data.Add("Tag", button.Tag);

        throw ex;
    }
}

然后像这样设置你的数据绑定：

radioButton1.Tag = "Option1";
radioButton2.Tag = "Option2";

foreach (RadioButtonUx rb in new RadioButtonUx[] { radioButton1, radioButton2 })
{
    Binding b = new Binding("Checked", this, "PropertyRBEnum");
    b.Format += FormatSelectedRadioButton<OptionEnum>;
    b.Parse += ParseSelectedRadioButton<OptionEnum>;

    rb.DataBindings.Add(b);
}

score 0 · Accepted Answer

我开始解决同样的问题。

我使用了 RadioButtonBinding 类，它封装了数据源中有关枚举的所有单选按钮。

下面这个类将所有单选按钮保存在一个列表中，并查找 enum ：

class RadioButtonBinding : ILookup<System.Enum, System.Windows.Forms.RadioButton>
{
    private Type enumType;
    private List<System.Windows.Forms.RadioButton> radioButtons;
    private System.Windows.Forms.BindingSource bindingSource;
    private string propertyName;

    public RadioButtonBinding(Type myEnum, System.Windows.Forms.BindingSource bs, string propertyName)
    {
        this.enumType = myEnum;
        this.radioButtons = new List<System.Windows.Forms.RadioButton>();
        foreach (string name in System.Enum.GetNames(this.enumType))
        {
            System.Windows.Forms.RadioButton rb = new System.Windows.Forms.RadioButton();
            rb.Text = name;
            this.radioButtons.Add(rb);
            rb.CheckedChanged += new EventHandler(rb_CheckedChanged);
        }
        this.bindingSource = bs;
        this.propertyName = propertyName;
        this.bindingSource.DataSourceChanged += new EventHandler(bindingSource_DataSourceChanged);
    }

    void bindingSource_DataSourceChanged(object sender, EventArgs e)
    {
        object obj = this.bindingSource.Current;
        System.Enum item = obj.GetType().GetProperty(propertyName).GetValue(obj, new object[] { }) as System.Enum;
        foreach (System.Enum value in System.Enum.GetValues(this.enumType))
        {
            if (this.Contains(value))
            {
                System.Windows.Forms.RadioButton rb = this[value].First();
                if (value.Equals(item))
                {
                    rb.Checked = true;
                }
                else
                {
                    rb.Checked = false;
                }
            }
        }
    }

    void rb_CheckedChanged(object sender, EventArgs e)
    {
        System.Windows.Forms.RadioButton rb = sender as System.Windows.Forms.RadioButton;
        System.Enum val = null;
        try
        {
            val = System.Enum.Parse(this.enumType, rb.Text) as System.Enum;
        }
        catch(Exception ex)
        {
            // cannot occurred if code is safe
            System.Windows.Forms.MessageBox.Show("No enum value for this radio button : " + ex.ToString());
        }
        object obj = this.bindingSource.Current;
        obj.GetType().GetProperty(propertyName).SetValue(obj, val, new object[] { });
        this.bindingSource.CurrencyManager.Refresh();
    }

    public int Count
    {
        get
        {
            return System.Enum.GetNames(this.enumType).Count();
        }
    }

    System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
    {
        return this.radioButtons.GetEnumerator();
    }

    public bool Contains(Enum key)
    {
        return System.Enum.GetNames(this.enumType).Contains(key.ToString());
    }

    public IEnumerable<System.Windows.Forms.RadioButton> this[Enum key]
    {
        get
        {
            return this.radioButtons.FindAll(a => { return a.Text == key.ToString(); });
        }
    }

    IEnumerator<IGrouping<Enum, System.Windows.Forms.RadioButton>> IEnumerable<IGrouping<Enum, System.Windows.Forms.RadioButton>>.GetEnumerator()
    {
        throw new NotImplementedException();
    }

    public void AddControlsIntoGroupBox(System.Windows.Forms.GroupBox gb)
    {
        System.Windows.Forms.FlowLayoutPanel panel = new System.Windows.Forms.FlowLayoutPanel();
        panel.Dock = System.Windows.Forms.DockStyle.Fill;
        panel.FlowDirection = System.Windows.Forms.FlowDirection.RightToLeft;
        foreach (System.Windows.Forms.RadioButton rb in this.radioButtons)
        {
            panel.Controls.Add(rb);
        }
        gb.Controls.Add(panel);
    }
}

您可以通过在表单的构造函数中添加该代码来将该类用于表单：

    public PageView()
    {
        InitializeComponent();
        RadioButtonBinding rbWidth = new RadioButtonBinding(typeof(Library.EnumConstraint), this.pageBindingSource, "ConstraintWidth");
        rbWidth.AddControlsIntoGroupBox(this.groupBox1);
        RadioButtonBinding rbHeight = new RadioButtonBinding(typeof(Library.EnumConstraint), this.pageBindingSource, "ConstraintHeight");
        rbHeight.AddControlsIntoGroupBox(this.groupBox3);
        this.pageBindingSource.CurrentItemChanged += new EventHandler(pageBindingSource_CurrentItemChanged);
    }

score 0 · Accepted Answer

将单选按钮的标签名称设置为代表值的名称。

创建一个字符串设置，例如 OptionDuplicateFiles，并为其指定默认单选按钮的标签名称的默认值。

要保存选中的单选按钮：

Settings.Default.OptionDuplicateFiles = gbxDuplicateFiles.Controls
   .OfType<RadioButton>()
   .Where(b => b.Checked)
   .Select(b => b.Tag)
   .First()
   .ToString();

要加载选中的单选按钮：

(gbxDuplicateFiles.Controls
   .OfType<RadioButton>()
   .Where(b => b.Tag.ToString() == Settings.Default.OptionDuplicateFiles)
   .First())
   .Checked = true;

多田！

score 0 · Accepted Answer

我喜欢 RadioButtonGroupBox 的想法，但我决定创建一个自支持的版本。没有理由为 Tag 属性添加值或引入新的值属性。任何分配的单选按钮仍然是 RadioButtonGroupBox 的成员，并且单选按钮的顺序是在开发过程中定义的。所以，我修改了代码。现在我可以通过索引位置、控件名称和文本来获取和设置选定的单选按钮。BTW Text 仅在您为每个单选按钮分配的 Text 不同时才可用。

public class RadioButtonGroupBox : GroupBox
{
    public event EventHandler SelectedChanged = delegate { };

    int _nIndexPosCheckRadioButton = -1;
    int _selected;
    public int Selected
    {
        get
        {
            return _selected;
        }
    }


    public int CheckedRadioButtonIndexPos
    {
        set
        {
            int nPosInList = -1;
            foreach (RadioButton item in this.Controls.OfType<RadioButton>())
            {
                // There are RadioButtonItems in the list...
                nPosInList++;

                // Set the RB that should be checked
                if (nPosInList == value)
                {
                    item.Checked = true;
                    // We can stop with the loop
                    break;
                }
            }
            _nIndexPosCheckRadioButton = nPosInList;
        }
        get
        {
            int nPosInList = -1;
            int nPosCheckeItemInList = -1;

            foreach (RadioButton item in this.Controls.OfType<RadioButton>())
            {
                // There are RadioButtonItems in the list...
                nPosInList++;

                // Find the RB that is checked
                if (item.Checked)
                {
                    nPosCheckeItemInList = nPosInList;
                    // We can stop with the loop
                    break;
                }
            }
            _nIndexPosCheckRadioButton = nPosCheckeItemInList;
            return _nIndexPosCheckRadioButton;
        }
    }

    public string CheckedRadioButtonByText
    {
        set
        {
            int nPosInList = -1;
            foreach (RadioButton item in this.Controls.OfType<RadioButton>())
            {
                // There are RadioButtonItems in the list...
                nPosInList++;

                // Set the RB that should be checked
                if (item.Text == value)
                {
                    item.Checked = true;
                    // We can stop with the loop
                    break;
                }
            }
            _nIndexPosCheckRadioButton = nPosInList;
        }
        get
        {
            string cByTextValue = "__UNDEFINED__";
            int nPosInList = -1;
            int nPosCheckeItemInList = -1;

            foreach (RadioButton item in this.Controls.OfType<RadioButton>())
            {
                // There are RadioButtonItems in the list...
                nPosInList++;

                // Find the RB that is checked
                if (item.Checked)
                {
                    cByTextValue = item.Text;
                    nPosCheckeItemInList = nPosInList;
                    // We can stop with the loop
                    break;
                }
            }
            _nIndexPosCheckRadioButton = nPosCheckeItemInList;
            return cByTextValue;
        }
    }

    public string CheckedRadioButtonByName
    {
        set
        {
            int nPosInList = -1;
            foreach (RadioButton item in this.Controls.OfType<RadioButton>())
            {
                // There are RadioButtonItems in the list...
                nPosInList++;

                // Set the RB that should be checked
                if (item.Name == value)
                {
                    item.Checked = true;
                    // We can stop with the loop
                    break;
                }
            }
            _nIndexPosCheckRadioButton = nPosInList;
        }
        get
        {
            String cByNameValue = "__UNDEFINED__";
            int nPosInList = -1;
            int nPosCheckeItemInList = -1;

            foreach (RadioButton item in this.Controls.OfType<RadioButton>())
            {
                // There are RadioButtonItems in the list...
                nPosInList++;

                // Find the RB that is checked
                if (item.Checked)
                {
                    cByNameValue = item.Name;
                    nPosCheckeItemInList = nPosInList;
                    // We can stop with the loop
                    break;
                }
            }
            _nIndexPosCheckRadioButton = nPosCheckeItemInList;
            return cByNameValue;
        }
    }


    protected override void OnControlAdded(ControlEventArgs e)
    {
        base.OnControlAdded(e);

        var radioButton = e.Control as RadioButton;
        if (radioButton != null)
            radioButton.CheckedChanged += radioButton_CheckedChanged;
    }


    void radioButton_CheckedChanged(object sender, EventArgs e)
    {
        _selected = CheckedRadioButtonIndexPos;
        SelectedChanged(this, new EventArgs());
    }

}

score 0 · Accepted Answer

我的方法是在将每个单选按钮绑定到布尔属性之前将它们放入自己的面板中：

    public static Binding Bind<TObject>(this RadioButton control, object dataSource, string dataMember)
    {
        // Put the radio button into its own panel
        Panel panel = new Panel();
        control.Parent.Controls.Add(panel);
        panel.Location = control.Location;
        panel.Size = control.Size;
        panel.Controls.Add(control);
        control.Location = new Point(0, 0);

        // Do the actual data binding
        return control.DataBindings.Add("Checked", dataSource, dataMember);
    }

score 0 · Accepted Answer

我想对可能对阅读这些帖子的人有所帮助的代码块进行观察。由于其结构，以下代码可能并不总是按预期工作。

try
    {
      val = System.Enum.Parse(this.enumType, rb.Text) as System.Enum;
    }
    catch(Exception ex)
    {
      // cannot occurred if code is safe
      System.Windows.Forms.MessageBox.Show("No enum value for this radio button : " + ex.ToString());
    }
    object obj = this.bindingSource.Current;
    obj.GetType().GetProperty(propertyName).SetValue(obj, val, new object[] {
    }
  );
  this.bindingSource.CurrencyManager.Refresh();

如果 try 块发生错误，就会执行 catch 块。代码将在 catch 块之后继续执行。由于没有处理绑定源，因此 catch 后面的变量可能最终处于不确定状态，并可能引发另一个可能会或可能不会被处理的异常。

更好的方法如下

 try
        {
            val = System.Enum.Parse(this.enumType, rb.Text) as System.Enum;

        object obj = this.bindingSource.Current;
        obj.GetType().GetProperty(propertyName).SetValue(obj, val, new object[] { });
        this.bindingSource.CurrencyManager.Refresh();
        }
        catch(EntityException ex)
        {
            // handle error
        }
        catch(Exception ex)
        {
            // cannot occurred if code is safe
            System.Windows.Forms.MessageBox.Show("No enum value for this radio button : " + ex.ToString());
        }

这允许处理枚举值错误以及可能发生的其他错误。但是，在 Exception 块之前使用 EntityException 或其变体（所有 Exception 的后代都必须先出现）。可以通过使用实体框架类而不是 Exception 基类来获取实体框架错误的特定实体状态信息。这有助于调试或为用户提供更清晰的运行时消息。

当我设置 try-catch 块时，我喜欢将其视为代码顶部的“层”。我决定异常在整个程序中的流程、它们向用户的显示，以及需要什么清理才能让程序继续正常工作，而对象不会处于不确定状态，可能会级联到其他错误。

c# - 在 WinForms 中对一组单选按钮进行数据绑定的最佳方法

9 回答 9

Related

Reference