c# – 更改按钮图像

预订操作将触发一个事件,表明设施已被预订.
Form1将注册一个事件处理程序并更改按钮的图像以反映设施的状态.

编辑(如何使用事件执行此操作)：

public class FacilityStateChangeEventArgs : EventArgs
{
    public FacilityStateChangeEventArgs(bool booked)
    {
        this.Booked = booked;
    }

    public bool Booked { get; protected set; }
    // ... other properties if you need them
}

public class Facility
{
    private bool booked = false;
    public bool Booked
    {
        get
        {
            return this.booked;
        }
        protected set
        {
            if (this.booked == value) return;


            // Changes the state and fires the event.
            this.booked = value;
            FireChange();
        }
    }

    public event EventHandler<FacilityStateChangeEventArgs> StateChange;

    // You will use this method when booked gets changed
    public void FireChange()
    {
        if (this.StateChange != null) this.StateChange(this,new FacilityStateChangeEventArgs(this.Booked));
    }
}

// The form with the image button.
public class FormWithButton
{
    Button button1 = new Button();

    public void Whatever()
    {
        // You will get the facility from your bussiness instances.
        Facility facility = new Facility();

        facility.StateChange += new EventHandler<FacilityStateChangeEventArgs>(facility_StateChange);
    }

    void facility_StateChange(object sender,FacilityStateChangeEventArgs e)
    {
        if (e.Booked) button1.Image = null; // booked image
        else button1.Image = null; // free image
    }
}