返回嵌套的通用Expression< Func< T，bool>.
问题描述：
错误消息是找不到类型或名称空间名称'T'."
The error message is "The type or namespace name 'T' could not be found."
???
public static Expression<Func<T, bool>> MakeFilter(string prop, object val)
{
ParameterExpression pe = Expression.Parameter(typeof(T), "p");
PropertyInfo pi = typeof(T).GetProperty(prop);
MemberExpression me = Expression.MakeMemberAccess(pe, pi);
ConstantExpression ce = Expression.Constant(val);
BinaryExpression be = Expression.Equal(me, ce);
return Expression.Lambda<Func<T, bool>>(be, pe);
}
相关链接:
答
您需要使方法本身具有通用性:
You need to make the method itself generic:
public static Expression<Func<T, bool>> MakeFilter<T>(string prop, object val)
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