制作類似Listbox的容器

一.設計時效果:

二.運行時效果:

 

三.簡單談談實現思路:

由於昨天時間比較緊張,沒有把全部的功能都做完善就發布出來了,今天把鍵盤操作給加上了,並修改了一些操作上的小BUG.將一些不必要顯示在設計時的屬性全部隱藏掉了.

這個控件實現起來比較簡單,主要由3部分組成,1為一個元素類,主要實現了BOUNDS屬性,以及實際的繪制每個元素的過程.2為一個集合類,這個類來管理儲存的元素.在新增,刪除元素時觸發公共事件.3為JcsItemList控件本身.它的變量成員中含有一個集合類,並在屬性中將之公開,這樣我們可以在設計時界面來完成元素的添加.在主要的ONPAINT方法中,來實際完成繪制標題,使用遍歷集合類元素的方法繪制各個元素.在滾動條的滾動事件中設置第一個繪制的元素的Bounds,並調整滾動條的最大值.

該控件當前實現的功能有:

1.繪制邊框

2.繪制標題

3.單元素選中.

4.雙擊元素觸發DoubleClickItem事件.

5.滾動條的點擊操作.

6.鼠標滑輪的滾動條移動操作.

7.提供鍵盤上下鍵的操作(滾動條將隨著移動).提供了在元素上的ENTER鍵的處理事件.

四.部分源代碼:

 

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Text;
using System.Windows.Forms;
using System.Drawing.Drawing2D;

namespace JcsCalendar
...{
    public partial class JcsItemList : UserControl
    ...{
        private const int  c_headerheight = 4 ;//抬頭高
        private const int c_seheight = 2;//間隔高
        private const int c_normalheight = 21;
        private int firstitemindex = 0 ;
        private int lastitemindex;
        private VIEwItemCollection itemcollection;
        private VScrollBar vscrollbar;
        private string m_caption = "JcsItemList";
        private JcsVIEwItem selecteditem;
        public delegate void ItemDoubleClick(JcsVIEwItem sender);
        public event ItemDoubleClick DoubleClickItem;
        
        //private OfficeRenderer render;
        public JcsItemList()
        ...{
            InitializeComponent();
            //render = new OfficeRenderer();
            this.BorderStyle = BorderStyle.FixedSingle  ;
            this.MinimumSize = new Size(100, c_normalheight * 2);
            this.BackColor = Color.White;

            vscrollbar = new VScrollBar();
            vscrollbar.SmallChange = c_normalheight;
            vscrollbar.LargeChange = c_normalheight * 2;
            vscrollbar.Dock = DockStyle.Right;
            this.Controls.Add(vscrollbar);
            //vscrollbar.Value = 21;
            vscrollbar.Scroll += new ScrollEventHandler(vscrollbar_Scroll);
            vscrollbar.MouseWheel += new MouseEventHandler(vscrollbar_MouseWheel);
            itemcollection = new VIEwItemCollection();
            itemcollection.CollectionChanged += new CollectionChangeEventHandler(itemcollection_CollectionChanged);
        }

        void vscrollbar_MouseWheel(object sender, MouseEventArgs e)
        ...{
            
        }
        /**//// <summary>
        /// 標題
        /// </summary>
        [Category("JCS屬性"),Description("容器標題")]
        public string Caption
        ...{
            get ...{ return this.m_caption ;}
            set 
            ...{
                this.m_caption = value;
                this.Invalidate();
            }

        }
        void vscrollbar_Scroll(object sender, ScrollEventArgs e)
        ...{
            int itemwidth = 0;
            itemwidth = this.Width - 2 - this.vscrollbar.Width;
            
            int firsttop = 22;
            int firstindex = (int)(System.Math.Ceiling((double)e.NewValue / c_normalheight));
            this.firstitemindex = firstindex;
            //itemcollection[firstindex].Visible = true ;
            int j = 0;
            for (int i = 0; i < itemcollection.Count; i++)
            ...{
                JcsViewItem item = itemcollection[i] as JcsVIEwItem;
                if (i < firstindex)
                ...{
                    item.Bounds = new Rectangle(1, 0, 0, 0);
                }
                else
                ...{
                    item.Bounds = new Rectangle(1, firsttop * (j + 1), itemwidth, c_normalheight);
                    j++;
                }
            }
            if(e.NewValue !=e.OldValue  )
            this.Invalidate();
            //MessageBox.Show(this.vscrollbar.Maximum.ToString());
            //MessageBox.Show(this.vscrollbar.Value.ToString());
        }
        private void adjustscroll()
        ...{
            if (this.Height >= this.itemcollection.Count * c_normalheight + 21)
            ...{
                this.vscrollbar.Visible = false;
                for (int i = 0; i < itemcollection.Count; i++)
                ...{
                    JcsViewItem item = itemcollection[i] as JcsVIEwItem;
                    item.Width = this.Width - 2;
                }
            }
            else
            ...{
                this.vscrollbar.Visible = true;
                for (int i = 0; i < itemcollection.Count; i++)
                ...{
                    JcsViewItem item = itemcollection[i] as JcsVIEwItem;
                    item.Width = this.Width - 2 - this.vscrollbar.Width ;
                }
                vscrollbar.Maximum = (this.itemcollection.Count + 1) * c_normalheight -&nbsp;this.Height + 2 * c_normalheight + c_normalheight;
                vscrollbar.Minimum = 0;
            }
        }
        void itemcollection_CollectionChanged(object sender, CollectionChangeEventArgs e)
        ...{
            int itemwidth = 0;
            if (this.vscrollbar.Visible)
            ...{
                itemwidth = this.Width - 2 - this.vscrollbar.Width;
            }
            else
            ...{
                itemwidth = this.Width - 2 ;
            }
            int firsttop = 22;
            for (int i = 0; i < itemcollection.Count; i++)
            ...{
                JcsViewItem item = itemcollection[i] as JcsVIEwItem;
                item.Bounds = new Rectangle(1,firsttop * (i+1) ,itemwidth ,c_normalheight );
            }
            this.adjustscroll();
            this.Invalidate();
        }
        /**//// <summary>
        /// 元素集合
        /// </summary>
        [DesignerSerializationVisibility(DesignerSerializationVisibility.Content),
        Category("JCS屬性"),Description("元素集合")]
        public VIEwItemCollection Items
        ...{
            get ...{ return itemcollection; }
        }
        public JcsVIEwItem SelectedItem
        ...{
            get ...{ return this.selecteditem; }
            set 
            ...{
                if (value != null)
                ...{
                    if (this.selecteditem != null)
                    ...{
                        this.selecteditem.IsMouseDown = false;
                        this.Invalidate(selecteditem.Bounds);
                    }

                    this.selecteditem = value;
                    this.selecteditem.IsMouseDown = true;
                    this.Invalidate(selecteditem.Bounds);
                }
            }
        }
        protected override void OnPaint(PaintEventArgs e)
        ...{
            base.OnPaint(e);
            Graphics g = e.Graphics;
            drawheader(g);
            drawitem(g);
        }
        protected override void OnResize(EventArgs e)
        ...{
            base.OnResize(e);
            //int t = this.Height%c_normalheight ;
            //if (t != 0)
            //    this.Height -= t ;
            adjustscroll();
        }
        private void drawheader(Graphics g)
        ...{
            using(SolidBrush b = new SolidBrush(Color.Black))
            ...{
                g.DrawString(this.m_caption , this.Font, b, 2, 4);
            }
            ControlPaint.DrawBorder3D(g, 0, 0, this.Width, c_normalheight, Border3DStyle.RaisedInner);
        }
        private void drawitem(Graphics g)
        ...{
            ItemFont itemfont = new ItemFont(this.Font ,Color.LightYellow   ,Color.Blue );
            for (int i = firstitemindex; i < this.itemcollection.Count; i++)
            ...{
                JcsViewItem item = itemcollection[i] as JcsVIEwItem;
                item.DrawVIEwItem(g, itemfont);
            }
        }
        protected override void OnMouseDown(MouseEventArgs e)
        ...{
            this.Focus();
            base.OnMouseDown(e);
            if (e.Button == MouseButtons.Left)
            ...{
                if (e.Clicks == 1)
                ...{
                    for (int i = 0; i < itemcollection.Count; i++)
                    ...{
                        JcsViewItem item = itemcollection[i] as JcsVIEwItem;
                        if (item.Bounds.Contains(e.Location))
                        ...{
                            this.SelectedItem = item;
                            //item.IsMouseDown = true;
                            //this.Invalidate(item.Bounds);
                            break;
                        }
                    }
                }
                else if (e.Clicks == 2)
                ...{
                    for (int i = 0; i < itemcollection.Count; i++)
                    ...{
                        JcsViewItem item = itemcollection[i] as JcsVIEwItem;
                        if (item.Bounds.Contains(e.Location))
                        ...{
                            this.DoubleClickItem(item);
                        }
                    }
                }
            }
        }
        protected override void OnMouseWheel(MouseEventArgs e)
        ...{
            base.OnMouseWheel(e);
            //MessageBox.Show(e.Y.ToString());
            if (e.Delta > 0)
            ...{
                if (this.vscrollbar.Visible)
                ...{
                    int currentvalue = this.vscrollbar.Value;
  &nb         if (currentvalue >0)
                    ...{
                        if (this.vscrollbar.Value - c_normalheight > 0)
                        ...{
                            this.vscrollbar.Value -= c_normalheight;
                        }
                        else
                        ...{
                            this.vscrollbar.Value = 0;
                        }
                        int itemwidth = 0;
                        itemwidth = this.Width - 2 - this.vscrollbar.Width;

                        int firsttop = 22;
                        int firstindex = (int)(System.Math.Ceiling((double)this.vscrollbar.Value / c_normalheight));
                        this.firstitemindex = firstindex;
                        //itemcollection[firstindex].Visible = true ;
                        int j = 0;
                        for (int i = 0; i < itemcollection.Count; i++)
                        ...{
                            JcsViewItem item = itemcollection[i] as JcsVIEwItem;
                            if (i < firstindex)
                            ...{
                                item.Bounds = new Rectangle(1, 0, 0, 0);
                            }
                            else
                            ...{
             item.Bounds = new Rectangle(1, firsttop * (j + 1), itemwidth, c_normalheight);
                                j++;
                            }
                        }
                        //if (e.NewValue != e.OldValue)
                        this.Invalidate();
                    }
                }
            }
            else
            ...{
                if (this.vscrollbar.Visible)
                ...{
                    int currentvalue = this.vscrollbar.Value;
                    if ((this.itemcollection.Count +1)* c_normalheight - currentvalue > this.Height - c_normalheight  )
   &n            ...{
                        this.vscrollbar.Value  += c_normalheight;
                        int itemwidth = 0;
                        itemwidth = this.Width - 2 - this.vscrollbar.Width;

                        int firsttop = 22;
                        int firstindex = (int)(System.Math.Ceiling((double)this.vscrollbar.Value / c_normalheight));
                        this.firstitemindex = firstindex;
                        //itemcollection[firstindex].Visible = true ;
                        int j = 0;
                        for (int i = 0; i < itemcollection.Count; i++)
                        ...{
                            JcsViewItem item = itemcollection[i] as JcsVIEwItem;
                            if (i < firstindex)
                            ...{
                                item.Bounds = new Rectangle(1, 0, 0, 0);
                            }
                            else
                            ...{
                                item.Bounds = new Rectangle(1, firsttop * (j + 1), itemwidth, c_normalheight);
                                j++;
                            }
                        }
                        //if (e.NewValue != e.OldValue)
                        this.Invalidate();
                    }
                }
            }
        }
    }
}