手把手教你如何扩展GridView之自带Excel和Word导出

最新重构源码下载：打造0代码全自动GridView-天具神力     
   
在web应用程序中，我们是不是很发愁打印问题，您是不是有过为了打印写Activex的经历，我们有没有想过，Word和Excel的打印功能能被我们利用起来呢?只要我们将我们将数据导出到Excel或者Word中，打印岂不是小case了么。下面就谈谈如何让GridView自己支持导出Excel和Word 。
    首先增加了两个属性，用于指示是否支持Excel导出和Word导出
 

  //增加了一个设置是否显示“导出Word”按钮的属性
        /**//// <summary>
        /// 排序提示信息
        /// </summary>
        [
        Description("显示导出到Word"),
        Category("扩展"),
         DefaultValue(true)
        ]
        public virtual bool ShowExportWord
        {
            get
            {
                object obj2 = this.ViewState["ShowExportWord"];
                if (obj2 != null)
                {
                    return (bool)obj2;
                }
                return true;
            }
            set
            {
                bool aShowExportWord = this.ShowExportWord;
                if (value != aShowExportWord)
                {
                    this.ViewState["ShowExportWord"] = value;
                    if (base.Initialized)
                    {
                        base.RequiresDataBinding = true;
                    }
                }
            }
        }
        //增加了一个设置是否显示“导出Excel”按钮的属性
        [
       Description("显示导出到Excel"),
       Category("扩展"),
       DefaultValue(true)
       ]
        public virtual bool ShowExportExcel
        {
            get
            {
                object obj2 = this.ViewState["ShowExportExcel"];
                if (obj2 != null)
                {
                    return (bool)obj2;
                }
                return true;
            }
            set
            {
                bool aShowExportExcel = this.ShowExportExcel;
                if (value != aShowExportExcel)
                {
                    this.ViewState["ShowExportExcel"] = value;
                    if (base.Initialized)
                    {
                        base.RequiresDataBinding = true;
                    }
                }
            }
        }

声明两个LinkButton控件btnExportWord,btnExport，分别用于点击导出Excel和点击导出word,并在控件的OnInit事件中初始化两个控件

声明两个LinkButton,并在控件的OnInit中初始化
   LinkButton btnExportWord;
        LinkButton btnExport; protected override void OnInit(EventArgs e)
        {
            this.EnableViewState = true;


            btnExport = new LinkButton();
            btnExport.CommandName = "ExportToExcel";
            btnExport.EnableViewState = true;
            btnExport.Text = "导出Excel";

            btnExportWord = new LinkButton();
            btnExportWord.CommandName = "ExportToWord";
            btnExportWord.EnableViewState = true;
            btnExportWord.Text = "导出Word";
 base.OnInit(e);
        }

将两个LinkButton添加到GridView子控件中。

 protected override int CreateChildControls(System.Collections.IEnumerable dataSource, bool dataBinding) {
            int res = base.CreateChildControls(dataSource, dataBinding);
                try
                {
                    GridViewRow row = new GridViewRow(0, 0, DataControlRowType.Pager, DataControlRowState.Normal);  TableCell cell2 = new TableCell();
                    cell2.HorizontalAlign = HorizontalAlign.Right;
                    cell2.Wrap = false; if (this.ShowExportExcel == true)
                    {
                        l1 = new Literal();
                        l1.Text = " [";
                        cell2.Controls.Add(l1);
                        cell2.Controls.Add(btnExport);
                        l1 = new Literal();
                        l1.Text = "] ";
                        cell2.Controls.Add(l1);
                    }

                    if (this.ShowExportWord == true)
                    {
                        l1 = new Literal();
                        l1.Text = " [";
                        cell2.Controls.Add(l1);
                        cell2.Controls.Add(btnExportWord);
                        l1 = new Literal();
                        l1.Text = "] ";
                        cell2.Controls.Add(l1);
                    } r.Cells.Add(cell2);
                    this.Controls[0].Controls.AddAt(0, row);
                }
                catch
                {
                }
            }
            return res;
        }

在导出的时候，我们希望一些列不被导出，如修改，删除这样的列，因此我们添加了这样的一个属性

用于指定不被导出列，列名之间用,隔开
  string _UnExportedColumnNames = "";
        [
  Description("不导出的数据列集合,将HeaderText用,隔开"),
  Category("扩展"),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Content),
        PersistenceMode(PersistenceMode.InnerProperty)

  ]
        public string UnExportedColumnNames
        {
            get
            {
                return _UnExportedColumnNames;
            }
            set
            {
                _UnExportedColumnNames = value;
            }
        }

在导出的时候，原来的GridView列表中会有一些LinkButton或者DropDownList控件，导出的时候，我们也希望将其换成纯文本，用下面这个函数可以完成这个目的

用于将GridView中的LinkButton和DropDownList转换成文本的方法
 private void DisableControls(Control gv)
        {

            LinkButton lb = new LinkButton();

            Literal l = new Literal();

            string name = String.Empty;

            for (int i = 0; i < gv.Controls.Count; i++)
            {

                if (gv.Controls[i].GetType() == typeof(LinkButton))
                {

                    l.Text = (gv.Controls[i] as LinkButton).Text;

                    gv.Controls.Remove(gv.Controls[i]);

                    gv.Controls.AddAt(i, l);

                }
                else if (gv.Controls[i].GetType() == typeof(DropDownList))
                {
                    l.Text = (gv.Controls[i] as DropDownList).SelectedItem.Text;

                    gv.Controls.Remove(gv.Controls[i]);

                    gv.Controls.AddAt(i, l);

                }

                if (gv.Controls[i].HasControls())
                {
                    DisableControls(gv.Controls[i]);
                }

            }
        }

下面是处理ItemCommand，将GridView导出的代码

处理OnRowCommand事件，将GridView数据导出到Excel和Word
  protected override void OnRowCommand(GridViewCommandEventArgs e)
        {
            base.OnRowCommand(e);
            if (e.CommandName == "ExportToExcel")
            {
                string[] ss = UnExportedColumnNames.Split(',');
                System.Collections.Generic.List<string> list = new System.Collections.Generic.List<string>();

                foreach (string s in ss)
                {
                    if (s != ",")
                    {
                        list.Add(s);
                    }
                }
                ShowToolBar = false;
                this.AllowSorting = false;
                HttpContext.Current.Response.Clear();

                HttpContext.Current.Response.AddHeader("content-disposition",
                "attachment;filename=" + ExcelFileName + ".xls");

                HttpContext.Current.Response.Charset = "GB2312";
                HttpContext.Current.Response.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");//设置输出流为简体中文
                HttpContext.Current.Response.ContentType = "application/ms-excel";


                System.IO.StringWriter stringWrite = new System.IO.StringWriter();

                System.Web.UI.HtmlTextWriter htmlWrite =
                new HtmlTextWriter(stringWrite);

                bool showCheckAll = ShowCheckAll;
                this.ShowCheckAll = false;
                this.AllowPaging = false;
                OnBind();
                DisableControls(this);
                foreach (DataControlField c in this.Columns)
                {
                    if (list.Contains(c.HeaderText) && !string.IsNullOrEmpty(c.HeaderText))
                    {
                        c.Visible = false;
                    }
                }
                this.RenderControl(htmlWrite);
                string content = System.Text.RegularExpressions.Regex.Replace(stringWrite.ToString(), "(<a[^>]+>)|(</a>)", "");
                HttpContext.Current.Response.Write(content);

                HttpContext.Current.Response.End();

                this.AllowPaging = true;
                this.AllowSorting = true;
                ShowToolBar = true;
                this.ShowCheckAll = showCheckAll;
                OnBind();
            }
            else if (e.CommandName == "ExportToWord")
            {
                string[] ss = UnExportedColumnNames.Split(',');
                System.Collections.Generic.List<string> list = new System.Collections.Generic.List<string>();

                foreach (string s in ss)
                {
                    if (s != ",")
                    {
                        list.Add(s);
                    }
                }
                ShowToolBar = false;
                this.AllowSorting = false;
                HttpContext.Current.Response.Clear();

                HttpContext.Current.Response.AddHeader("content-disposition",
                "attachment;filename=" + ExcelFileName + ".doc");

                HttpContext.Current.Response.Charset = "GB2312";
                HttpContext.Current.Response.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");//设置输出流为简体中文
                HttpContext.Current.Response.ContentType = "application/ms-word";


                System.IO.StringWriter stringWrite = new System.IO.StringWriter();

                System.Web.UI.HtmlTextWriter htmlWrite =
                new HtmlTextWriter(stringWrite);

                bool showCheckAll = ShowCheckAll;
                this.ShowCheckAll = false;
                this.AllowPaging = false;
                OnBind();

                DisableControls(this);
                foreach (DataControlField c in this.Columns)
                {
                    if (list.Contains(c.HeaderText) && !string.IsNullOrEmpty(c.HeaderText))
                    {
                        c.Visible = false;
                    }
                }
                this.RenderControl(htmlWrite);
                string content = System.Text.RegularExpressions.Regex.Replace(stringWrite.ToString(), "(<a[^>]+>)|(</a>)", "");
                HttpContext.Current.Response.Write(content);

                HttpContext.Current.Response.End();

                this.AllowPaging = true;
                this.AllowSorting = true;
                ShowToolBar = true;
                ShowCheckAll = showCheckAll;
                OnBind();
            }
        }

使用的时候，只要指定ShowExportExcel=True，ShowExportWord=True就自动出现导出Word和导出Excel的按钮了，点击自动会将GridView中的数据导出到Word或者Excel中了，如果原GridView是多页的，那也会自动将全部数据（而不是当前页的数据）导出，而且会剔除原来数据中的一些超级链接。使用起来相当简单，效果页非常好。
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