<Button>列为属性。</button> <Button>不向面板添加按钮</button>

Question

I am trying to create a custom panel where I can change the properties using Properties -> Buttons -> [(Collection) ...]:

The following is what I have tried

public class CustomPanel : Panel
{
    private List<Button> buttons = new List<Button>();

    public List<Button> Buttons
    {
        get { return buttons; }
        set 
        {
             buttons = value;
             this.Controls.Clear();
                
             foreach (var button in buttons)
             {
                button.Size = new Size(200, 30);
                this.Controls.Add(button);
             }
         }
    }
}

But when I add a new button using Properties -> Buttons -> [(Collection) ...]: it is not adding it to my panel.

Answer 1

Assuming a CustomPanel class has been added as a custom control, and its base class changed to Panel , you can try the following code.

using System.ComponentModel;
using System.ComponentModel.Design;
using System.Drawing;
using System.Drawing.Design;
using System.Linq;
using System.Windows.Forms;

namespace TEST
{
    public partial class CustomPanel : Panel
    {
        public CustomPanel()
        {
            InitializeComponent();
        }

        [Editor(typeof(ArrayEditor), typeof(UITypeEditor))]
        public Button[] Buttons
        {
            get { return this.Controls.OfType<Button>().ToArray(); }
            set
            {
                SuspendLayout();
                try
                {
                    this.Controls.Clear();

                    foreach (var button in value)
                    {
                        button.Size = new Size(200, 30);
                        this.Controls.Add(button);
                    }
                }
                finally { ResumeLayout(); }
            }
        }
    }
}

Make sure the project has a reference to System.Design.dll , for ArrayEditor to be recognized.

Keep in mind that:

• Every Button control added by the designer through the Buttons property will be serialized like it was added in the usual design way.
• Adding other (non- Button ) controls is still possibile in the usual design way, or programmatically.
• this.Controls.Clear will remove any control, even the ones added without using Buttons ; you can delete this instruction if you want to preserve them, but you will need a way to recognize the previously existing buttons and replace or keep them as needed.
• All properties of any Button object can be edited inside the ArrayEditor form.
• You need to handle positioning of the Button controls (both newly added and existing ones) in order to avoid overlapping.

I suggest to use a child FlowLayoutPanel for automatic positioning of the buttons and to prevent anyone to mess directly with the collection of buttons. With this approach, this.Controls will become flowLayoutPanel1.Controls (or similar). Otherwise, you should override OnControlAdded and OnControlRemoved to be notified when any control is added or removed.