灵活掌握Asp.net MVC中GridView的使用方法

本文教程为大家分享了GridView控件的使用方法和具体实现代码，供大家参考，具体内容如下

Models文件下实体类:

 public class Customer
 {
 public int Id { get; set; } 
 public string CompanyName { get; set; } 
 public string ContactTitle { get; set; }
 public string Address { get; set; }
 public string City { get; set; }  
 public string Country { get; set; }
 public string Phone { get; set; }
 public DateTime Founded { get; set; }
 }

 public class CustomersViewModel

 {
 public IQueryable<Customer> Customers { get; set; }

 public PagingInfo PagingInfo { get; set; }

 public string JsonPagingInfo { get; set; }
 }

 public static class ExpresssionBuilder
 {
 private static readonly MethodInfo containsMethod = typeof(string).GetMethod("Contains");
 private static readonly MethodInfo startsWithMethod = typeof(string).GetMethod("StartsWith", new Type[] { typeof(string) });
 private static readonly MethodInfo endsWithMethod = typeof(string).GetMethod("EndsWith", new Type[] { typeof(string) });


 public static Expression<Func<T,bool>> GetExpression<T>(IList<FilterObject> filters)
 {
  if (filters.Count == 0)
  return null;

  ParameterExpression param = Expression.Parameter(typeof(T), "t");
  Expression exp = null;

  if (filters.Count == 1)
  exp = GetExpression<T>(param, filters[0]);
  else if (filters.Count == 2)
  exp = GetExpression<T>(param, filters[0], filters[1]);
  else
  {
  while (filters.Count > 0)
  {
   var f1 = filters[0];
   var f2 = filters[1];

   if (exp == null)
   exp = GetExpression<T>(param, filters[0], filters[1]);
   else
   exp = Expression.AndAlso(exp, GetExpression<T>(param, filters[0], filters[1]));

   filters.Remove(f1);
   filters.Remove(f2);

   if (filters.Count == 1)
   {
   exp = Expression.AndAlso(exp, GetExpression<T>(param, filters[0]));
   filters.RemoveAt(0);
   }
  }
  }

  return Expression.Lambda<Func<T, bool>>(exp, param);
 }

 private static Expression GetExpression<T>(ParameterExpression param, FilterObject filter)
 {
  MemberExpression member = Expression.Property(param, filter.Column);
  //ConstantExpression constant = Expression.Constant(filter.Value);

  //新的逻辑来处理可空Decimal和DateTime值
  UnaryExpression constant = null;
  if (member.Type == typeof(Decimal?))
  {
  constant = Expression.Convert(Expression.Constant(Decimal.Parse(filter.Value)) , member.Type);
  }
  else if (member.Type == typeof(DateTime?))
  {
  constant = Expression.Convert(Expression.Constant(DateTime.Parse(filter.Value)), member.Type);
  }
  else
  {
  constant = Expression.Convert(Expression.Constant(filter.Value), member.Type);
  }


  switch (filter.Operator)
  {
  case FilterOperator.Equals:
   return Expression.Equal(member, constant);

  case FilterOperator.GreaterThan:
   return Expression.GreaterThan(member, constant);

  case FilterOperator.GreaterThanOrEqual:
   return Expression.GreaterThanOrEqual(member, constant);

  case FilterOperator.LessThan:
   return Expression.LessThan(member, constant);

  case FilterOperator.LessThanOrEqual:
   return Expression.LessThanOrEqual(member, constant);

  case FilterOperator.Contains:
   return Expression.Call(member, containsMethod, constant);

  case FilterOperator.StartsWith:
   return Expression.Call(member, startsWithMethod, constant);

  case FilterOperator.EndsWith:
   return Expression.Call(member, endsWithMethod, constant);

  case FilterOperator.NotEqual:
   return Expression.Negate(Expression.Equal(member, constant));
  }

  return null;
 }

 private static BinaryExpression GetExpression<T> (ParameterExpression param, FilterObject filter1, FilterObject filter2)
 {
  Expression bin1 = GetExpression<T>(param, filter1);
  Expression bin2 = GetExpression<T>(param, filter2);

  return Expression.AndAlso(bin1, bin2);
 }
 }

 public class PagingInfo
 {
 public List<int> PageOptions { get; set; }

 public bool ShowPageOptions { get; set; }

 public int TotalItems { get; set; }
 public int ItemsPerPage { get; set; }
 public int CurrentPage { get; set; }

 public int TotalPages
 {
  get { return (int)Math.Ceiling((decimal)TotalItems / (ItemsPerPage != 0 ? ItemsPerPage : 1)); }
 }

 public SortObject Sort { get; set; }

 public IList<FilterObject> Filters { get; set; }

 public string SearchTerm { get; set; }
 }

 public class SortObject
 {
 public String SortColumn { get; set; }

 public SortDirection Direction { get; set; }
 }

 public class FilterObject
 {
 public string Column { get; set; } 

 public string Value { get; set; }

 public FilterOperator Operator { get; set; }

 public FilterConjunction Conjunction { get; set; }
 }


 /********* ENUMS *************/
 public enum SortDirection
 {
 NotSet,
 Ascending,
 Descending
 }

 public enum FilterOperator
 {
 Contains,
 GreaterThan,
 GreaterThanOrEqual,
 LessThan,
 LessThanOrEqual,
 StartsWith,
 EndsWith,
 Equals,
 NotEqual
 }

 public enum FilterConjunction
 {
 And,
 Or
 }

 public class Extensions
 {
 public static string GetWhereClause(FilterObject filterObj, Type valueType)
 {  
  string whereClause = "true";
  if (valueType != typeof (DateTime))
  {
  switch (filterObj.Operator)
  {
   case FilterOperator.Contains:
   if (valueType == typeof (string))
    whereClause += string.Format(" {0} {1}.Contains(\"{2}\")", filterObj.Conjunction,
    filterObj.Column, filterObj.Value);
   break;
   case FilterOperator.GreaterThan:
   if (valueType != typeof (string))
    whereClause += string.Format(" {0} {1} > {2}", filterObj.Conjunction, filterObj.Column,
    filterObj.Value);
   break;
   case FilterOperator.GreaterThanOrEqual:
   if (valueType != typeof (string))
    whereClause += string.Format(" {0} {1} >= {2}", filterObj.Conjunction, filterObj.Column,
    filterObj.Value);
   break;
   case FilterOperator.LessThan:
   if (valueType != typeof (string))
    whereClause += string.Format(" {0} {1} < {2}", filterObj.Conjunction, filterObj.Column,
    filterObj.Value);
   break;
   case FilterOperator.LessThanOrEqual:
   if (valueType != typeof (string))
    whereClause += string.Format(" {0} {1} <= {2}", filterObj.Conjunction, filterObj.Column,
    filterObj.Value);
   break;
   case FilterOperator.StartsWith:
   if (valueType != typeof (string))
    whereClause += string.Format(" {0} {1}.StartsWith(\"{2}\")", filterObj.Conjunction,
    filterObj.Column, filterObj.Value);
   break;
   case FilterOperator.EndsWith:
   if (valueType != typeof (string))
    whereClause += string.Format(" {0} {1}.EndsWith(\"{2}\")", filterObj.Conjunction,
    filterObj.Column, filterObj.Value);
   break;
   case FilterOperator.Equals:

   whereClause +=
    string.Format(valueType == typeof (string) ? " {0} {1} == \"{2}\"" : " {0} {1} == {2}",
    filterObj.Conjunction, filterObj.Column, filterObj.Value);
   break;
   case FilterOperator.NotEqual:

   whereClause +=
    string.Format(valueType == typeof (string) ? " {0} {1} != \"{2}\"" : " {0} {1} != {2}",
    filterObj.Conjunction, filterObj.Column, filterObj.Value);
   break;
   default:
   throw new ArgumentOutOfRangeException();
  }
  }
  else
  {
  DateTime dt;
  DateTime.TryParse(filterObj.Value, out dt);

  switch (filterObj.Operator)
  {
   case FilterOperator.Contains:   
   break;
   case FilterOperator.GreaterThan:

    whereClause += string.Format(