Dot Net WinForm 控件开发 (七) 为属性提下拉式属性编辑器

1、先画出用于下拉编辑器UI的用户控件

代码：

 1using System;
 2using System.Collections.Generic;
 3using System.ComponentModel;
 4using System.Drawing;
 5using System.Data;
 6using System.Text;
 7using System.Windows.Forms;
 8
 9namespace CustomControlSample
10{
11    [DesignTimeVisible(false)] //不显示在ToolBox中
12    public partial class UcSimpleCustomTypeDropDownEditor : UserControl
13    {
14        private SimpleCustomType _oldSCT;
15        private SimpleCustomType _newSCT;
16        private bool canceling = false; // 按Esc 键，关闭下拉菜单，不更新值。
17
18        public SimpleCustomType SCT
19        {
20            get { return _newSCT; }
21        }
22
23        public UcSimpleCustomTypeDropDownEditor(SimpleCustomType sct)
24        {
25            _oldSCT = sct;
26            _newSCT = sct;
27            InitializeComponent();
28        }
29
30        private void UcSimpleCustomTypeDropDownEditor_Load(object sender, EventArgs e)
31        {
32            this.textBox1.Text = _oldSCT.Min.ToString();
33            this.textBox2.Text = _oldSCT.Max.ToString();
34        }
35
36        private void textBox1_Validating(object sender, CancelEventArgs e)
37        {
38            try
39            {
40                int.Parse(textBox1.Text);
41            }
42            catch (FormatException)
43            {
44                e.Cancel = true;
45                MessageBox.Show("无效的值。", "验证错误", MessageBoxButtons.OK, MessageBoxIcon.Error);
46            }
47        }
48
49        private void textBox2_Validating(object sender, CancelEventArgs e)
50        {
51            try
52            {
53                int.Parse(textBox2.Text);
54            }
55            catch (FormatException)
56            {
57                e.Cancel = true;
58                MessageBox.Show("无效的值。", "验证错误", MessageBoxButtons.OK, MessageBoxIcon.Error);
59            }
60        }
61
62        protected override bool ProcessDialogKey(Keys keyData)
63        {
64            if (keyData == Keys.Escape)
65            {
66                canceling = true;
67            }
68            return base.ProcessDialogKey(keyData);
69        }
70
71        private void UcSimpleCustomTypeDropDownEditor_Leave(object sender, EventArgs e)
72        {
73            if (!canceling)
74            {
75                SCT.Min = int.Parse(this.textBox1.Text);
76                SCT.Max = int.Parse(this.textBox2.Text);
77            }
78        }
79    }
80}
81

2、再编写属性值编辑器类

 1SimpleCustomTypeDropDownEditor#region SimpleCustomTypeDropDownEditor
 2    /**//// <summary>
 3    /// SimpleCustomType 值编辑器 for DropDown
 4    /// </summary>
 5    public class SimpleCustomTypeDropDownEditor : UITypeEditor
 6    {
 7        public override UITypeEditorEditStyle GetEditStyle(ITypeDescriptorContext context)
 8        {
 9            if (context != null && context.Instance != null)
10            {
11                return UITypeEditorEditStyle.DropDown;
12            }
13            return base.GetEditStyle(context);
14        }
15
16        public override object EditValue(ITypeDescriptorContext context, System.IServiceProvider provider, object value)
17        {
18            System.Windows.Forms.Design.IWindowsFormsEditorService editorService = null;
19            if (context != null && context.Instance != null && provider != null)
20            {
21                editorService = (System.Windows.Forms.Design.IWindowsFormsEditorService)provider.GetService(typeof(System.Windows.Forms.Design.IWindowsFormsEditorService));
22                if (editorService != null)
23                {
24                    CustomControl control = (CustomControl)context.Instance;
25                    UcSimpleCustomTypeDropDownEditor drop = new UcSimpleCustomTypeDropDownEditor(control.DropDownProperty);
26                    editorService.DropDownControl(drop);
27                    value = drop.SCT;
28                    return value;
29                }
30            }
31
32            return value;
33        }
34    }
35    #endregion

3、再添加一个属性，并用EditorAttribute 指定相应的编辑器类

 1下拉属性值编辑对话框的属性#region 下拉属性值编辑对话框的属性
 2        // 注意：这里设置了复杂属性的初始值 new SimpleCustomType(1, 2)
 3        private SimpleCustomType dropDownField = new SimpleCustomType(1, 2);
 4
 5        [Category("下拉式属性值编辑对话框")]
 6        [TypeConverter(typeof(SimpleCustomTypeConverter))]
 7        [Editor(typeof(SimpleCustomTypeDropDownEditor), typeof(UITypeEditor))]
 8        public SimpleCustomType DropDownProperty
 9        {
10            get { return dropDownField; }
11            set { dropDownField = value; }
12        }
13        #endregion

The end.