private object EvalFromHttpContext(HttpContext context, ContextDataAttribute attr, ParameterInfo p)
{
// 直接从HttpRequest对象中获取数据，根据Attribute中指定的表达式求值。
string expression = attr.Expression;
object requestData = null;
if (expression.StartsWith("Request."))
{
requestData = System.Web.UI.DataBinder.Eval(context.Request, expression.Substring(8));
}
else if (expression.StartsWith("HttpRuntime."))
{
PropertyInfo property = typeof(HttpRuntime).GetProperty(expression.Substring(12), BindingFlags.Static | BindingFlags.Public);
if (property == null)
{
throw new ArgumentException(string.Format("参数 {0} 对应的ContextDataAttribute计算表达式 {1} 无效：", p.Name, expression));
}
requestData = property.FastGetValue(null);
}
else
{
requestData = System.Web.UI.DataBinder.Eval(context, expression);
}
if (requestData == null)
{
return(null);
}
else
{
if (requestData.GetType().IsCompatible(p.ParameterType))
{
return(requestData);
}
else
{
throw new ArgumentException(string.Format("参数 {0} 的申明的类型与HttpRequest对应属性的类型不一致。", p.Name));
}
}
}
public void Test_ContextDataAttribute2()
{
ContextDataAttribute a = new ContextDataAttribute(string.Empty);
}
public void Test_ContextDataAttribute()
{
ContextDataAttribute a = new ContextDataAttribute(null);
}
