扩展GridView（三）——单击命令按钮弹出确认框

扩展GridView（三）——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。
复制C#代码保存代码/// <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
复制C#代码保存代码/// <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
复制C#代码保存代码/// <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
复制C#代码保存代码/// <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
复制C#代码保存代码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、在继承自GridView的那个类的构造函数内加一个RowDataBound事件的处理，在该事件内实现单击命令按钮弹出确认框的功能。
复制C#代码保存代码/// <summary>
/// 构造函数
/// </summary>
public SmartGridView()
: base()
{
// 新增“SmartGridView_RowDataBound”事件处理
this.RowDataBound += new GridViewRowEventHandler(SmartGridView_RowDataBound);
}

/// <summary>
/// RowDataBound事件
/// </summary>
/// <param name=”sender”>sender</param>
/// <param name=”e”>e</param>
protected void SmartGridView_RowDataBound(object sender, GridViewRowEventArgs e)
{
SmartGridView sgv = (SmartGridView) sender;

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;
}
}
}
}
}
}
}
}

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
复制C#代码保存代码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()
{
//
// TOD 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
复制ASPX代码保存代码<%@ 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>

<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>