本篇文章介紹的是在sharepoint 2010中用VS 2010開發自定義webpart。

        自定義開發的webpart分為兩種：帶引數的和不帶引數的；帶引數的分為需要繫結外部資料的和不需要繫結外部資料的。

        不帶引數的webpart：

                這種webpart開發最簡單，只需要將webpart頁面的後臺邏輯處理完就可以，不需要外來的引數。

        不需要繫結外部資料的帶引數的webpart：

                這種webpart開發，需要在繼承system.web.ui.webcontrols.webparts.webpart的類中增加引數，即如下形式的程式碼：

                     [Personalizable(),
                     WebDisplayNameAttribute("FullUrl"),
                     WebBrowsable]
                     public string FullUrl
                     {
                         get;
                         set;
                     }

                也可增加emun型別的下拉列表引數（但是其中的引數是在程式碼中寫死的）。

       需要繫結外部資料的帶引數的webpart：

                這種webpart的開發相對比較麻煩，除了需要在繼承system.web.ui.webcontrols.webparts.webpart的類中增加引數之外，還需要在繼承system.web.ui.webcontrols.webparts.Editorpart的類中繫結外來資料並傳給繼承system.web.ui.webcontrols.webparts.webpart的類中的引數。

               在繼承system.web.ui.webcontrols.webparts.Editorpart的類中，需要過載方法：

                       1. protected override void CreateChildControls()：該方法是用來構建編輯webpart時選擇引數的頁面；

                       2.public override void SyncChanges()：該方法是用來繫結外部資料到webpart編輯頁面的控制元件中的；

                       3.public override bool ApplyChanges()：該方法是用來將編輯頁面中控制元件的值回傳給繼承system.web.ui.webcontrols.webparts.webpart的類中的引數。

               例子如下：

    [ToolboxItemAttribute(false)]
    public class Statistics_Monthly : WebPart
    {

        [Personalizable(),
        WebDisplayNameAttribute("工作量統計類別")]
        public string BisicCategory
        {
            get;
            set;
        }

        [Personalizable(),
        WebDisplayNameAttribute("工作量統計時間")]
        public string StatisticsTime
        {
            get;
            set;
        }

        // 當更改可視 Web 部件專案項時，Visual Studio 可能會自動更新此路徑。
        private const string _ascxPath = @"~/_CONTROLTEMPLATES/StatisticsWebPart_Monthly/Statistics_Monthly/Statistics_MonthlyUserControl.ascx";

        protected override void CreateChildControls()
        {
            Control control = Page.LoadControl(_ascxPath);

            if (control != null)
            {
                ((Statistics_MonthlyUserControl)control).webPart = this;
            }

            Controls.Add(control);
        }

        public override EditorPartCollection CreateEditorParts()
        {
            EditorPartCollection baseParts = base.CreateEditorParts();
            List<EditorPart> editorParts = new List<EditorPart>(1);
            EditorPart part = new Statistics_Monthly_Edit();
            part.ID = this.ID + "_Statistics_Monthly_Editor";
            part.Title = "Statistics_Monthly變數選擇";
            editorParts.Add(part);
            return new EditorPartCollection(baseParts, editorParts);
        }

    }

    public class Statistics_Monthly_Edit : EditorPart
    {

        protected Label label_BasicCategory;
        protected DropDownList ddl_BasicCategory;
        protected Label label_Time;
        protected DropDownList ddl_Year;
        protected Label label_Year;
        protected DropDownList ddl_Month;
        protected Label label_Month;

        protected override void CreateChildControls()
        {
            base.CreateChildControls();

            this.label_BasicCategory = new Label();
            this.label_BasicCategory.Text = "工作量統計型別：";
            this.ddl_BasicCategory = new DropDownList();
            this.ddl_BasicCategory.AutoPostBack = true;
            this.ddl_BasicCategory.SelectedIndexChanged += new EventHandler(ddl_BasicCategory_SelectedIndexChanged);

            this.label_Time = new Label();
            this.label_Time.Text = "請選擇顯示時間：";
            this.ddl_Year = new DropDownList();
            this.ddl_Year.AutoPostBack = true;
            this.ddl_Year.SelectedIndexChanged += new EventHandler(ddl_Year_SelectedIndexChanged);
            this.label_Year = new Label();
            this.label_Year.Text = "年";
            this.ddl_Month = new DropDownList();
            this.ddl_Month.AutoPostBack = true;
            this.ddl_Month.SelectedIndexChanged += new EventHandler(ddl_Month_SelectedIndexChanged);
            this.label_Month = new Label();
            this.label_Month.Text = "月";

            Table tb = new Table();

            TableRow row = new TableRow();
            TableCell cell1 = new TableCell();
            TableCell cell2 = new TableCell();
            cell1.Controls.Add(this.label_BasicCategory);
            cell2.Controls.Add(this.ddl_BasicCategory);
            row.Cells.Add(cell1);
            row.Cells.Add(cell2);
            tb.Rows.Add(row);

            row = new TableRow();
            cell1 = new TableCell();
            cell2 = new TableCell();
            cell1.Controls.Add(this.label_Time);
            cell2.Controls.Add(this.ddl_Year);
            cell2.Controls.Add(this.label_Year);
            cell2.Controls.Add(this.ddl_Month);
            cell2.Controls.Add(this.label_Month);
            row.Cells.Add(cell1);
            row.Cells.Add(cell2);
            tb.Rows.Add(row);

            this.Controls.Add(tb);
        }

        protected void ddl_BasicCategory_SelectedIndexChanged(object sender, EventArgs e)
        {
           
        }

        protected void ddl_Year_SelectedIndexChanged(object sender, EventArgs e)
        {
           
        }

        protected void ddl_Month_SelectedIndexChanged(object sender, EventArgs e)
        {
           
        }

        public override bool ApplyChanges()
        {
            this.EnsureChildControls();
            Statistics_Monthly webpart = this.WebPartToEdit as Statistics_Monthly;
            if (webpart == null)
            {
                return false;
            }
            else
            {
                if (this.ddl_BasicCategory.SelectedItem != null)
                {
                    webpart.BisicCategory = this.ddl_BasicCategory.SelectedValue;
                }
                else
                {
                    webpart.BisicCategory = string.Empty;
                }

                if ((this.ddl_Year.SelectedItem != null) && (this.ddl_Month.SelectedItem != null))
                {
                    webpart.StatisticsTime = this.ddl_Year.SelectedValue + "/" + this.ddl_Month.SelectedValue;
                }
                else
                {
                    webpart.StatisticsTime = string.Empty;
                }
                return true;
            }
        }

        public override void SyncChanges()
        {           
           EnsureChildControls();
           Statistics_Monthly webpart = this.WebPartToEdit as Statistics_Monthly;
           if (webpart != null)
           {
               InitBasicCategory(webpart);
               InitStatisticsTime(webpart);
           }
        }

        
        private void InitBasicCategory(Statistics_Monthly webpart)
        {

           從外部獲取值並繫結到this.ddl_BasicCategory下拉列表中。
        }

        private void InitStatisticsTime(Statistics_Monthly webpart)
        {

           從外部獲取值並繫結到this.ddl_Year和this.ddl_Month的dropdownlist中的值。
        }

   }