C# 如何定義讓PropertyGrid控件顯示[...]按鈕，並且點擊後以下拉框形式顯示自定義控件編輯屬性值

首先定義一個要在下拉框顯示的控件：

using System;
using System.Windows.Forms;
namespace Simon.WinForms.Examples.PropertyGrid
{
    public class EditorControl : UserControl
    {
        public EditorControl()
        {
            this.label1 = new System.Windows.Forms.Label();
            this.label1.AutoSize = true;
            this.label1.Location = new System.Drawing.Point(21, 24);
            this.label1.Name = "label1";
            this.label1.Size = new System.Drawing.Size(41, 12);
            this.label1.TabIndex = 0;
            this.label1.Text = "名稱：";

            this.comboBox1 = new System.Windows.Forms.ComboBox();
            this.comboBox1.FormattingEnabled = true;
            this.comboBox1.Items.AddRange(new object[] {
            "名稱一",
            "名稱二",
            "名稱三",
            "名稱四"});
            this.comboBox1.Location = new System.Drawing.Point(56, 21);
            this.comboBox1.Name = "comboBox1";
            this.comboBox1.Size = new System.Drawing.Size(133, 20);
            this.comboBox1.TabIndex = 2;
            this.comboBox1.SelectedIndexChanged += new System.EventHandler(this.comboBox1_SelectedIndexChanged);

            this.SuspendLayout();
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 12F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.Controls.Add(this.comboBox1);
            this.Controls.Add(this.label1);
            this.Name = "EditorControl";
            this.Size = new System.Drawing.Size(210, 64);
            this.ResumeLayout(false);
            this.PerformLayout();
        }

        private Label label1;
        private ComboBox comboBox1;

        public string result = "";
        private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            result = comboBox1.SelectedItem.ToString();
        }
    }
}

從System.Drawing.Design.UITypeEditor繼承一個自定義屬性編輯管理器類，參考如下：

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

namespace Simon.WinForms.Examples.PropertyGrid
{
    public class Editor : UITypeEditor
    {
        public override UITypeEditorEditStyle GetEditStyle(System.ComponentModel.ITypeDescriptorContext context)
        {
            // 編輯屬性值時，在右側顯示...更多按鈕
            return UITypeEditorEditStyle.Modal;
        }

        public override object EditValue(System.ComponentModel.ITypeDescriptorContext context, System.IServiceProvider provider, object value)
        {
            var edSvc = provider.GetService(typeof(IWindowsFormsEditorService)) as IWindowsFormsEditorService;
            if (edSvc != null)
            {
                var popedControl = new EditorControl();
                // 還有ShowDialog這種方式，可以彈出一個窗體來進行編輯
                edSvc.DropDownControl(popedControl);
                value = popedControl.result;
            }
            return base.EditValue(context, provider, value);
        }
    }
}

定義一個使用PropertyGrid顯示屬性的類型。

using System.ComponentModel;

namespace Simon.WinForms.Examples.PropertyGrid
{
    public class ShowedClass
    {
        [DisplayName("名稱")]
        [Editor(typeof(Editor), typeof(System.Drawing.Design.UITypeEditor))]
        public string Name { get; set; }

        [Editor(typeof(Editor), typeof(System.Drawing.Design.UITypeEditor))]
        public string Description { get; set; }
    }
}

在窗體上放好PropertyGrid，然後把你的類實例化後讓PropertyGrid來顯示設置就可以看到效果了。

propertyGrid1.SelectedObject = new ShowedClass() { Name="我沒名字"};