c#:为对象的字段值更改时创建一个事件

// 定义委托类型
public delegate void FieldChangedEventHandler(object sender, FieldChangedEventArgs e);

// 定义事件参数类
public class FieldChangedEventArgs : EventArgs
{
    public string FieldName { get; set; }
    public object NewValue { get; set; }
}

// 定义包含事件的类
public class MyClass
{
    // 声明事件
    public event FieldChangedEventHandler FieldChanged;

    private string myField;

    public string MyField
    {
        get { return myField; }
        set
        {
            if (myField != value)
            {
                myField = value;
                OnFieldChanged("MyField", value);
            }
        }
    }

    protected virtual void OnFieldChanged(string fieldName, object newValue)
    {
        // 触发事件
        FieldChanged?.Invoke(this, new FieldChangedEventArgs { FieldName = fieldName, NewValue = newValue });
    }
}

// 使用事件的示例
public class Program
{
    static void Main(string[] args)
    {
        MyClass myObject = new MyClass();

        // 订阅事件
        myObject.FieldChanged += MyObject_FieldChanged;

        // 修改字段值
        myObject.MyField = "New Value";
    }

    static void MyObject_FieldChanged(object sender, FieldChangedEventArgs e)
    {
        Console.WriteLine($"Field '{e.FieldName}' changed to '{e.NewValue}'");
    }
}