Sharepoint 2010 控件系统 之 扩展 SaveButton

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　　        上一篇介绍了Sharepoint控件的基本应用，这一篇介绍一下SaveButton的扩展，在扩展之前讲个案例，通过两个字段验证唯一性，这样在开发时就要用到扩展了，但用EventReceive也可以，哪个更好就自己体会吧。


        SaveButton目前不支付保存前事件和保存后事件，但是在开发项目时，保存前总要用到验证，因此为了更好的满足要求，合理规划代码就有了扩展这一篇文章，对SaveButton扩展了两个事件，保存前BeforeSaveItem，保存后AfterSaveItem，这两个事件在实际应用中应用比较多。

       首先声明事件和委托，如果对事件和委托不清楚可以Google一下，分页就是最好的事例。




/// <summary>
/// 保存前
/// </summary>
public class BeforeSaveItemArgs : EventArgs
{
/// <summary>当前列表的ListItem</summary>
public SPListItem ListItem { get; set; }
/// <summary>默认True，如果是False，则验证通不过，不能保存</summary>
public bool Validate { get; set; }
/// <summary>当前列表的 List</summary>
public SPList List { get; set; }
public Dictionary<string, string> Parameters { get; set; }
}
/// <summary>
/// 保存后
/// </summary>
public class AfterSaveItemArgs : EventArgs
{
/// <summary>当前列表的 List</summary>
public SPList List { get; set; }
/// <summary>当前列表的ListItem</summary>
public SPListItem ListItem { get; set; }
/// <summary>判断是否保存成功</summary>
public bool Success { get; set; }
public Dictionary<string, string> Parameters { get; set; }
}
/// <summary>
/// 声明委托 保存前事件
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
public delegate void BeforeSaveItemHandler(object sender, BeforeSaveItemArgs e);
/// <summary>
/// 声明委托 保存后事件
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
public delegate void AfterSaveItemHandler(object sender, AfterSaveItemArgs e);
　　继承SaveButton ，Override SaveItem ，下面为所有的代码


View Code


public class TSaveButton : SaveButton
{
private static readonly object EventBeforeSaveItem = new object();
private static readonly object EventAfterSaveItem = new object();
#region Event
/// <summary>
/// 定义保存前事件
/// </summary>
public event BeforeSaveItemHandler BeforeSaveItem
{
add
{
base.Events.AddHandler(EventBeforeSaveItem, value);
}
remove
{
base.Events.RemoveHandler(EventBeforeSaveItem, value);
}
}
/// <summary>
/// 定义保存后事件
/// </summary>
public event AfterSaveItemHandler AfterSaveItem
{
add
{
base.Events.AddHandler(EventAfterSaveItem, value);
}
remove
{
base.Events.RemoveHandler(EventAfterSaveItem, value);
}
}
#endregion
protected virtual void SaveIteming(BeforeSaveItemArgs e)
{
BeforeSaveItemHandler handler = (BeforeSaveItemHandler)base.Events[EventBeforeSaveItem];
if (handler != null)
{
handler(this, e);
}
}
protected virtual void SaveItemed(AfterSaveItemArgs e)
{
AfterSaveItemHandler handler = (AfterSaveItemHandler)base.Events[EventAfterSaveItem];
if (handler != null)
{
handler(this, e);
}
}
/// <summary>
/// Override SaveItem
/// </summary>
/// <returns></returns>
protected override bool SaveItem()
{
SPListItem item = base.ItemContext.ListItem; //获取当前Items

BeforeSaveItemArgs beforeSaveArgs =
new BeforeSaveItemArgs() { ListItem = item, Validate = true, List = base.List }; //构造默认值
            SaveIteming(beforeSaveArgs);
if (beforeSaveArgs.Validate) //验证保存是否成功
            {
bool result = base.SaveItem(); //保存成功返回True
AfterSaveItemArgs afterSaveArgs =
new AfterSaveItemArgs() { ListItem = item, Success = result,List = base.List};
SaveItemed(afterSaveArgs);
return result;
}
else
return false;
}
}
　　扩展完成之后，就是如何运用了，在上一篇中已经提到了这两个事件 OnBeforeSaveItem OnAfterSaveItem



<T:TSaveButton runat="server" ID="btnSave" OnInit="OnInitSave" OnBeforeSaveItem="BeforeSaveItem" OnAfterSaveItem="AfterSaveItem" />
　　现在事件已经注册好了，接下来就是写 BeforeSaveItem的方法



#region OnBeforeSaveItem
public void BeforeSaveItem(object sender, EventArgs e)
{
BeforeSaveItemArgs beforeSaveItemArgs = e as BeforeSaveItemArgs;
if (beforeSaveItemArgs != null)
{
beforeSaveItemArgs.Validate = false;
if (ValidateCode(beforeSaveItemArgs.ListItem.ID, beforeSaveItemArgs.ListItem.Title, txtCodeKey.Text, beforeSaveItemArgs.List))
{
beforeSaveItemArgs.ListItem["ParentId"] = hfParentId.Value;
beforeSaveItemArgs.Validate = true;
}
else
{
Page.ClientScript.RegisterClientScriptBlock(typeof(Page), "ModalHostScript", "alert('代码已存在！');", true);
return;
}
beforeSaveItemArgs.Validate = false;
if (ValidateCodeName(beforeSaveItemArgs.ListItem.ID, txtCodeName.Text, txtCodeKey.Text, beforeSaveItemArgs.List))
{
beforeSaveItemArgs.Validate = true;
}
else
{
Page.ClientScript.RegisterClientScriptBlock(typeof(Page), "ModalHostScript", "alert('名称已存在！');", true);
}
}
}
#endregion
　　就这样完成了SaveButton的扩展。如果有其它特殊要求就自己扩展吧。
　　参考文章：http://www.cnblogs.com/myheaven/archive/2011/04/29/2032892.html