GridView控件——单击命令按钮弹出确认框

介绍
给按钮增加单击弹出确认框的功能是经常要用到的，我们一般是通过在RowDataBound事件里编码的方式实现，麻烦，所以扩展一下。


控件开发
1、新建一个继承自GridView的类。

/**//// <summary>
/// 继承自GridView
/// </summary>
[ToolboxData(@"<{0}:SmartGridView runat='server'></{0}:SmartGridView>")]
public class SmartGridView : GridView
{
}

2、新建一个ConfirmButton类，有两个属性

    /**//// <summary>
    /// ConfirmButton 的摘要说明。
    /// </summary>
    [ToolboxItem(false)]
    [TypeConverter(typeof(ConfirmButtonConverter))]
    public class ConfirmButton
    {
        private string _commandName;
        /**//// <summary>
        /// 按钮的CommandName
        /// </summary>
        public string CommandName
        {
            get { return this._commandName; }
            set { this._commandName = value; }
        }

        private string _confirmMessage;
        /**//// <summary>
        /// 确认框弹出的信息
        /// </summary>
        public string ConfirmMessage
        {
            get { return this._confirmMessage; }
            set { this._confirmMessage = value; }
        }
    }

3、新建一个继承自CollectionBase的类ConfirmButtons

    /**//// <summary>
    /// ProjectGroups 的摘要说明。
    /// 注意要继承自CollectionBase
    /// </summary>
    [
    ToolboxItem(false),
    ParseChildren(true)
    ]
    public class ConfirmButtons : CollectionBase
    {
        /**//// <summary>
        /// 构造函数
        /// </summary>
        public ConfirmButtons()
            : base()
        {
        }

        /**//// <summary>
        /// 实现IList接口
        /// 获取或设置指定索引处的元素。
        /// </summary>
        /// <param name="index">要获得或设置的元素从零开始的索引</param>
        /// <returns></returns>
        public ConfirmButton this[int index]
        {
            get
            {
                return (ConfirmButton)base.List[index];
            }
            set
            {
                base.List[index] = (ConfirmButton)value;
            }
        }

        /**//// <summary>
        /// 实现IList接口
        /// 将某项添加到 System.Collections.IList 中。
        /// </summary>
        /// <param name="item">要添加到 System.Collections.IList 的 System.Object。</param>
        public void Add(ConfirmButton item)
        {
            base.List.Add(item);
        }

        /**//// <summary>
        /// 实现IList接口
        /// 从 System.Collections.IList 中移除特定对象的第一个匹配项。
        /// </summary>
        /// <param name="index">要从 System.Collections.IList 移除的 System.Object</param>
        public void Remove(int index)
        {
            if (index > -1 && index < base.Count)
            {
                base.List.RemoveAt(index);
            }
        }
    }

4、新建一个继承自ExpandableObjectConverter的类ConfirmButtonConverter

    /**//// <summary>
    /// 类型转换器
    /// </summary>
    public class ConfirmButtonConverter : ExpandableObjectConverter
    {
        /**//// <summary>
        /// 返回值能否将ConfirmButton类型转换为String类型
        /// </summary>
        /// <param name="context"></param>
        /// <param name="destinationType"></param>
        /// <returns></returns>
        public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType)
        {
            if (destinationType == typeof(string))
            {
                return true;
            }
            return base.CanConvertTo(context, destinationType);
        }

        /**//// <summary>
        /// 将ConfirmButton类型转换为String类型
        /// </summary>
        /// <param name="context"></param>
        /// <param name="culture"></param>
        /// <param name="value"></param>
        /// <param name="destinationType"></param>
        /// <returns></returns>
        public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture,
            object value, Type destinationType)
        {
            if (value != null)
            {
                if (!(value is YYControls.SmartGridView.ConfirmButton))
                {
                    throw new ArgumentException(
                        "无效的ConfirmButton", "value");
                }
            }

            if (destinationType.Equals(typeof(string)))
            {
                if (value == null)
                {
                    return String.Empty;
                }
                return "ConfirmButton";
            }
            return base.ConvertTo(context, culture, value, destinationType);
        }
    }

5、在继承自GridView的类中加一个复杂对象属性，该复杂对象就是第3步创建的那个ConfirmButtons

        private ConfirmButtons _confirmButtons;
        /**//// <summary>
        /// 确认按钮集合
        /// </summary>
        [
        PersistenceMode(PersistenceMode.InnerProperty),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Content),
        Description("确认按钮集合，确认按钮的CommandName和提示信息"),
        Category("扩展")
        ]
        public virtual ConfirmButtons ConfirmButtons
        {
            get
            {
                if (_confirmButtons == null)
                {
                    _confirmButtons = new ConfirmButtons();
                }
                return _confirmButtons;
            }
        }

6、重写OnRowDataBound实现单击命令按钮弹出确认框的功能。主要是给按钮增加一个客户端的onclick事件。

        /**//// <summary>
        /// OnRowDataBound
        /// </summary>
        /// <param name="e"></param>
        protected override void OnRowDataBound(GridViewRowEventArgs e)
        {
            if (e.Row.RowType == DataControlRowType.DataRow)
            {
                if (this._confirmButtons != null)
                {
                    // GridViewRow的每个TableCell
                    foreach (TableCell tc in e.Row.Cells)
                    {
                        // TableCell里的每个Control
                        foreach (Control c in tc.Controls)
                        {
                            // 如果控件继承自接口IButtonControl
                            if (c.GetType().GetInterface("IButtonControl") != null && c.GetType().GetInterface("IButtonControl").Equals(typeof(IButtonControl)))
                            {
                                // 从用户定义的ConfirmButtons集合中分解出ConfirmButton
                                foreach (ConfirmButton cb in _confirmButtons)
                                {
                                    // 如果发现的按钮的CommandName在ConfirmButtons有定义的话
                                    if (((IButtonControl)c).CommandName == cb.CommandName)
                                    {
                                        // 增加确认框属性
                                        ((IAttributeAccessor)c).SetAttribute("onclick", "return confirm('" + cb.ConfirmMessage + "')");
                                        break;
                                    }
                                }
                            }
                        }
                    }
                }
            }

            base.OnRowDataBound(e);
        }

控件使用
添加这个控件到工具箱里，然后拖拽到webform上，设置其ConfirmButtons属性即可。CommandName是命令按钮的CommandName属性；ConfirmMessage是弹出的确认框所显示的文字。
ObjData.cs

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

using System.ComponentModel;

/**//// <summary>
/// OjbData 的摘要说明
/// </summary>
public class OjbData
{
    public OjbData()
    {
        //
        // TODO: 在此处添加构造函数逻辑
        //
    }

    [DataObjectMethod(DataObjectMethodType.Select, true)]
    public DataTable Select()
    {
        DataTable dt = new DataTable();
        dt.Columns.Add("no", typeof(string));
        dt.Columns.Add("name", typeof(string));

        for (int i = 0; i < 30; i++)
        {
            DataRow dr = dt.NewRow();
            dr[0] = "no" + i.ToString().PadLeft(2, '0');
            dr[1] = "name" + i.ToString().PadLeft(2, '0');

            dt.Rows.Add(dr);
        }

        return dt;
    }
}

Default.aspx

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>无标题页</title>
</head>
<body>
    <form id="form1" runat="server">
        <div>
            &nbsp;
            <yyc:SmartGridView ID="SmartGridView1" runat="server" AutoGenerateColumns="false"
                DataSourceID="ObjectDataSource1">
                <Columns>
                    <asp:BoundField DataField="no" HeaderText="序号" SortExpression="no" />
                    <asp:BoundField DataField="name" HeaderText="名称" SortExpression="name" />
                    <asp:ButtonField CommandName="ConfirmTest" Text="确认按钮测试" />
                </Columns>
                <ConfirmButtons>
                    <yyc:ConfirmButton ConfirmMessage="确认删除吗？" CommandName="ConfirmTest"></yyc:ConfirmButton>
                </ConfirmButtons>
            </yyc:SmartGridView>
            <asp:ObjectDataSource ID="ObjectDataSource1" runat="server" SelectMethod="Select"
                TypeName="OjbData"></asp:ObjectDataSource>
        </div>
    </form>
</body>
</html>

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