绑定属性以在Winforms中控制

Question

将属性绑定到控件的最佳方法是什么,以便在更改属性值时,控件的绑定属性随之更改.

所以,如果我有一个属性FirstName,我想绑定到文本框的txtFirstName文本值.因此,如果我更改FirstName为值"Stack",则属性txtFirstName.Text也会更改为值"Stack".

我知道这可能听起来是一个愚蠢的问题,但我会感谢你的帮助.

Answer 1

您必须实现INotifyPropertyChanged并添加绑定到文本框.

我将提供C#代码段.希望能帮助到你

class Sample : INotifyPropertyChanged
{
    private string firstName;
    public string FirstName
    {
        get { return firstName; }
        set
        {
            firstName = value;
            InvokePropertyChanged(new PropertyChangedEventArgs("FirstName"));
        }
    }

    #region Implementation of INotifyPropertyChanged

    public event PropertyChangedEventHandler PropertyChanged;

    public void InvokePropertyChanged(PropertyChangedEventArgs e)
    {
        PropertyChangedEventHandler handler = PropertyChanged;
        if (handler != null) handler(this, e);
    }

    #endregion
}

用法:

 Sample sourceObject = new Sample();
 textbox.DataBindings.Add("Text",sourceObject,"FirstName");
 sourceObject.FirstName = "Stack"; 

Answer 2

一个简化版本接受的答案的，不需要你在每一个属性setter喜欢手动键入属性的名称OnPropertyChanged("some-property-name")。相反，您只是OnPropertyChanged()不带参数调用：

您至少需要.NET 4.5。 CallerMemberName在System.Runtime.CompilerServices名称空间中

public class Sample : INotifyPropertyChanged
{
    private string _propString;
    private int _propInt;


    //======================================
    // Actual implementation
    //======================================
    public event PropertyChangedEventHandler PropertyChanged;

    [NotifyPropertyChangedInvocator]
    protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
    {
        var handler = PropertyChanged;
        if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
    }
    //======================================
    // END: actual implementation
    //======================================


    public string PropString
    {
        get { return _propString; }
        set
        {
            // do not trigger change event if values are the same
            if (Equals(value, _propString)) return;
            _propString = value;

            //===================
            // Usage in the Source
            //===================
            OnPropertyChanged();

        }
    }

    public int PropInt
    {
        get { return _propInt; }
        set
        {
            // do not allow negative numbers, but always trigger a change event
            _propInt = value < 0 ? 0 : value;
            OnPropertyChanged();
        }
    }
}

用法保持不变：

var source = new Sample();
textbox.DataBindings.Add("Text", source, "PropString");
source.PropString = "Some new string";

希望这对某人有帮助。