asp.net项目出现 实例失败

[zxg680]

错误:
实例失败。
说明: 执行当前 Web 请求期间，出现未处理的异常。请检查堆栈跟踪信息，以了解有关该错误以及代码中导致错误的出处的详细信息。

异常详细信息: System.InvalidOperationException: 实例失败。

源错误:


行 164: {
行 165: Console.WriteLine(e.Message);
行 166: throw e;
行 167: }
行 168:


源文件: F:\Program Files\easyMule\Incoming\asp.net与extjs开发点卡在线销售系统\Y2毕业设计\项目源码\GameCardShop\GameCardShopDAL\Auto\CardTypeService.cs 行: 166
堆栈跟踪:

[InvalidOperationException: 实例失败。]
GameCardShop.DAL.CardTypeService.GetCardTypesBySql(String safeSql) in F:\Program Files\easyMule\Incoming\asp.net与extjs开发点卡在线销售系统\Y2毕业设计\项目源码\GameCardShop\GameCardShopDAL\Auto\CardTypeService.cs:166
GameCardShop.DAL.CardTypeService.GetAllCardTypes() in F:\Program Files\easyMule\Incoming\asp.net与extjs开发点卡在线销售系统\Y2毕业设计\项目源码\GameCardShop\GameCardShopDAL\Auto\CardTypeService.cs:102
GameCardShop.BLL.CardTypeManager.GetAllCardTypes() in F:\Program Files\easyMule\Incoming\asp.net与extjs开发点卡在线销售系统\Y2毕业设计\项目源码\GameCardShop\GameCardShopBLL\Auto\CardTypeManager.cs:37

[TargetInvocationException: 调用的目标发生了异常。]
System.RuntimeMethodHandle._InvokeMethodFast(Object target, Object[] arguments, SignatureStruct& sig, MethodAttributes methodAttributes, RuntimeTypeHandle typeOwner) +0
System.RuntimeMethodHandle.InvokeMethodFast(Object target, Object[] arguments, Signature sig, MethodAttributes methodAttributes, RuntimeTypeHandle typeOwner) +72
System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean skipVisibilityChecks) +308
System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture) +29
System.Web.UI.WebControls.ObjectDataSourceView.InvokeMethod(ObjectDataSourceMethod method, Boolean disposeInstance, Object& instance) +480
System.Web.UI.WebControls.ObjectDataSourceView.ExecuteSelect(DataSourceSelectArguments arguments) +1960
System.Web.UI.WebControls.BaseDataList.GetData() +57
System.Web.UI.WebControls.DataList.CreateControlHierarchy(Boolean useDataSource) +284
System.Web.UI.WebControls.BaseDataList.OnDataBinding(EventArgs e) +56
System.Web.UI.WebControls.BaseDataList.DataBind() +52
System.Web.UI.WebControls.BaseDataList.EnsureDataBound() +76
System.Web.UI.WebControls.BaseDataList.CreateChildControls() +63
System.Web.UI.Control.EnsureChildControls() +87
System.Web.UI.Control.PreRenderRecursiveInternal() +50
System.Web.UI.Control.PreRenderRecursiveInternal() +170
System.Web.UI.Control.PreRenderRecursiveInternal() +170
System.Web.UI.Control.PreRenderRecursiveInternal() +170
System.Web.UI.Control.PreRenderRecursiveInternal() +170
System.Web.UI.Control.PreRenderRecursiveInternal() +170
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +2041


源代码是

        private static IList<CardType> GetCardTypesBySql( string safeSql )
        {
            List<CardType> list = new List<CardType>();

			try
			{
147行－－－－－－                  DataTable table = DBHelper.GetDataSet( safeSql );
				
				foreach (DataRow row in table.Rows)
				{
					CardType cardType = new CardType();
					
					cardType.CardTypeId = (int)row["CardTypeId"];
					cardType.CardTypeName = (string)row["CardTypeName"];
					cardType.CardPrice = (int)row["CardPrice"];
					cardType.CardImage = (string)row["CardImage"];
	
					list.Add(cardType);
				}
	
				return list;
			}
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
166行－－－      throw e;              }

        }

我设置断点，发现只执行到147行，输出：
名称 值 类型
safesql "select * from CardType" String
table null System.Data.DataTable
list count＝0

大家分析分析，给个意见，谢谢

[xray2005]

foreach (DataRow row in table.Rows)
                {
                    CardType cardType = new CardType();
                    
                    cardType.CardTypeId =row["CardTypeId"]==null?-1: (int)row["CardTypeId"];
                    cardType.CardTypeName =row["CardTypeName"]==null?string.Empty: (string)row["CardTypeName"];
                    cardType.CardPrice =row["CardPrice"]==null?-1: (int)row["CardPrice"];
                    cardType.CardImage =row["CardImage"]==null?string.Empty: (string)row["CardImage"];
    
                    list.Add(cardType);
                }

[xray2005]

试试

[xierfly]

我设置断点，发现只执行到147行，输出：
名称 值 类型
safesql "select * from CardType" String
table null System.Data.DataTable
list count＝0

=====
没有获取到值。在没有值的情况下 ，你foreach (DataRow row in table.Rows)可能出问题，先判断一下table的rowsv.count ，然后foreach

[wuyq11]

DataTable table = DBHelper.GetDataSet( safeSql );
foreach (DataRow row in table.Rows)
{
CardType cardType = new CardType();
cardType.CardTypeId = row["CardTypeId"]==DBNull.Value?0:(int)row["CardTypeId"];
cardType.CardTypeName =row["CardTypeName"]==DBNull.Value?"": (string)row["CardTypeName"];
cardType.CardPrice =row["CardPrice"]==DBNull.Value?0:(int)row["CardPrice"];
cardType.CardImage =row["CardImage"]== DBNull.Value?"":(string)row["CardImage"];
list.Add(cardType);
}
return list;

[wuyq11]

在查询分析器执行select * from CardType看看

[zxg680]

谢谢以上各位帮忙，xray2005，wuyq11二位的代码我试了试不成功，主要是执行到147行
DataTable table = DBHelper.GetDataSet( safeSql ); 后，table是null，直接就异常了，foreach就没执行。 我想肯定是147行的错了，我再看看前面的。select * from CardType查询有数据4列30多行呢

[zxg680]

谢谢 ♂风车车.Net ，a Rookie.，人生如梦的关注，问题已经解决了，原因是数据库连接方法DBHelper.GetDataSet（）出问题了。导致数据库连不上查询不出数据。还是谢谢你们