winforms - 如何在 NavBarGroup 中获得 CheckEdit

Question

我们需要在 NavBarGroup 的标题中放置一个复选框(及其标题)。有办法做到这一点吗？

Answer 1

我们创建了一个 NavBarGroupChecked 类 (NavBarGroupChecked.cs)，它继承自 NavBarGroup，可以直接放入其中替换它。它添加了一个跟踪复选框并实现自定义绘制的 RepositoryItemCheckEdit 成员。它有一个 Checked 属性，告诉您它是否被选中，以及一个在 Checked 状态更改时调用的事件。差不多就是这样。只需投入使用即可。

代码在下面还有downloadable here .

// built from http://www.devexpress.com/example=E2061

using System;
using System.ComponentModel;
using System.Drawing;
using System.Reflection;
using System.Windows.Forms;
using DevExpress.XtraEditors.Drawing;
using DevExpress.XtraEditors.Repository;
using DevExpress.XtraEditors.ViewInfo;
using DevExpress.XtraNavBar;
using DevExpress.XtraNavBar.ViewInfo;

namespace AutoTagCore.net.windward.controls
{
    /// <summary>
    /// A NavBarGroup that has a check box (with caption) in its header.
    /// </summary>
    public class NavBarGroupChecked : NavBarGroup
    {

        /// <summary>
        /// Occurs when the Checked property value has been changed. 
        /// </summary>
        public event EventHandler CheckedChanged;

        private const int CHECK_BOX_WIDTH = 15;
        private bool isLocked;
        private RepositoryItemCheckEdit _GroupEdit;
        private NavBarControl _NavBarControl;
        private Rectangle hotRectangle;

        /// <summary>
        /// Initializes a new instance of the <see cref="T:DevExpress.XtraNavBar.NavBarGroup"/> class, with the specified caption.
        /// </summary>
        /// <param name="caption">A string representing the NavBar group's caption.</param>
        public NavBarGroupChecked(string caption)
            : base(caption)
        {
            ctor();
        }

        private void ctor()
        {
            GroupEdit = new RepositoryItemCheckEdit { GlyphAlignment = DevExpress.Utils.HorzAlignment.Far };
            GroupEdit.Appearance.Options.UseTextOptions = true;
            GroupEdit.Appearance.TextOptions.HAlignment = DevExpress.Utils.HorzAlignment.Far;
            GroupEdit.GlyphAlignment = DevExpress.Utils.HorzAlignment.Far;
            ItemChanged += NavBarGroupChecked_ItemChanged;
        }

        private void NavBarGroupChecked_ItemChanged(object sender, System.EventArgs e)
        {
            if (NavBar != NavBarControl)
                NavBarControl = NavBar;
        } 


        /// <summary>
        /// Creates an instance of the <see cref="T:DevExpress.XtraNavBar.NavBarGroup"/> class.
        /// </summary>
        public NavBarGroupChecked()
        {
            ctor();
        }

        /// <summary>
        /// The NavBarControl that owns this. This must be set to work.
        /// </summary>
        private NavBarControl NavBarControl
        {
            get { return _NavBarControl; }
            set { UnsubscribeEvents(value); _NavBarControl = value; SubscribeEvents(value); }
        }

        private void SubscribeEvents(NavBarControl navBarControl)
        {
            if (navBarControl == null)
                return;
            NavBarControl.CustomDrawGroupCaption += NavBarControl_CustomDrawGroupCaption;
            NavBarControl.MouseClick += NavBarControl_MouseClick;
        }

        private void UnsubscribeEvents(NavBarControl navBarControl)
        {
            if (navBarControl != null)
                return;
            NavBarControl.CustomDrawGroupCaption -= NavBarControl_CustomDrawGroupCaption;
            NavBarControl.MouseClick -= NavBarControl_MouseClick;
        }

        /// <summary>
        /// true if the box is checked.
        /// </summary>
        public bool Checked { get; set; }

        /// <summary>
        /// The indent of the check box for the end of the header.
        /// </summary>
        public int CheckIndent { get; set; }

        ///<summary>
        /// The check box displayed in the header.
        ///</summary>
        [DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]
        public RepositoryItemCheckEdit GroupEdit
        {
            get { return _GroupEdit; }
            set { _GroupEdit = value; }
        }

        private Rectangle GetCheckBoxBounds(Rectangle fixedCaptionBounds)
        {
            return new Rectangle(fixedCaptionBounds.Right - CHECK_BOX_WIDTH - CheckIndent, fixedCaptionBounds.Top, CHECK_BOX_WIDTH, fixedCaptionBounds.Height); 
        }

        private bool IsCustomDrawNeeded(NavBarGroup group)
        {
            return GroupEdit != null && NavBarControl != null && !isLocked && group == this;
        }

        private void NavBarControl_CustomDrawGroupCaption(object sender, CustomDrawNavBarElementEventArgs e)
        {
            NavGroupInfoArgs infoArgs = (NavGroupInfoArgs) e.ObjectInfo;
            if (!IsCustomDrawNeeded(infoArgs.Group))
                return;
            try
            {
                isLocked = true;
                BaseNavGroupPainter painter = NavBarControl.View.CreateGroupPainter(NavBarControl);
                Rectangle checkBoxBounds = GetCheckBoxBounds(infoArgs.CaptionBounds);
                painter.DrawObject(infoArgs);
                DrawCheckBox(e.Graphics, checkBoxBounds);
                e.Handled = true;
            }
            finally
            {
                isLocked = false;
            }
        }

        private void DrawCheckBox(Graphics g, Rectangle r)
        {
            BaseEditPainter painter = GroupEdit.CreatePainter();
            BaseEditViewInfo info = GroupEdit.CreateViewInfo();
            info.EditValue = Checked;
            SizeF textBounds = info.Appearance.CalcTextSize(g, GroupEdit.Caption, 500);
            int totalWidth = (int)textBounds.Width + r.Width + 10;
            info.Bounds = new Rectangle(r.Right - totalWidth, r.Y, totalWidth, r.Height);
            info.CalcViewInfo(g);
            ControlGraphicsInfoArgs args = new ControlGraphicsInfoArgs(info, new DevExpress.Utils.Drawing.GraphicsCache(g), r);
            painter.Draw(args);
            args.Cache.Dispose();
        }

        private static NavBarViewInfo GetNavBarView(NavBarControl NavBar)
        {
            PropertyInfo pi = typeof(NavBarControl).GetProperty("ViewInfo", BindingFlags.Instance | BindingFlags.NonPublic);
            return pi.GetValue(NavBar, null) as NavBarViewInfo;
        }

        private bool IsCheckBox(Point p)
        {
            NavBarHitInfo hi = NavBarControl.CalcHitInfo(p);
            if (hi.Group == null || hi.Group != this)
                return false;
            NavBarViewInfo vi = GetNavBarView(NavBarControl);
            vi.Calc(NavBarControl.ClientRectangle);
            NavGroupInfoArgs groupInfo = vi.GetGroupInfo(hi.Group);
            Rectangle checkBounds = GetCheckBoxBounds(groupInfo.CaptionBounds);
            hotRectangle = checkBounds;
            return checkBounds.Contains(p);
        }

        private void NavBarControl_MouseClick(object sender, MouseEventArgs e)
        {
            if (!IsCheckBox(e.Location))
                return;
            Checked = !Checked;
            NavBarControl.Invalidate(hotRectangle);
            if (CheckedChanged != null)
                CheckedChanged(sender, e);
        }
    }
}