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An OrderBy extension method for IQueryable that takes string
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| public static IQueryable<T> OrderBy<T>(this IQueryable<T> source, string sortExpression) | |
| { | |
| if (source == null) | |
| throw new ArgumentNullException("source", "source is null."); | |
| if (string.IsNullOrEmpty(sortExpression)) | |
| throw new ArgumentException("sortExpression is null or empty.", "sortExpression"); | |
| var parts = sortExpression.Split(' '); | |
| var isDescending = false; | |
| var propertyName = ""; | |
| var tType = typeof(T); | |
| if (parts.Length > 0 && parts[0] != "") | |
| { | |
| propertyName = parts[0]; | |
| if (parts.Length > 1) | |
| { | |
| isDescending = parts[1].ToLower().Contains("esc"); | |
| } | |
| PropertyInfo prop = tType.GetProperty(propertyName); | |
| if (prop == null) | |
| { | |
| throw new ArgumentException(string.Format("No property '{0}' on type '{1}'", propertyName, tType.Name)); | |
| } | |
| var funcType = typeof(Func<,>) | |
| .MakeGenericType(tType, prop.PropertyType); | |
| var lambdaBuilder = typeof(Expression) | |
| .GetMethods() | |
| .First(x => x.Name == "Lambda" && x.ContainsGenericParameters && x.GetParameters().Length == 2) | |
| .MakeGenericMethod(funcType); | |
| var parameter = Expression.Parameter(tType); | |
| var propExpress = Expression.Property(parameter, prop); | |
| var sortLambda = lambdaBuilder | |
| .Invoke(null, new object[] { propExpress, new ParameterExpression[] { parameter } }); | |
| var sorter = typeof(Queryable) | |
| .GetMethods() | |
| .FirstOrDefault(x => x.Name == (isDescending ? "OrderByDescending" : "OrderBy") && x.GetParameters().Length == 2) | |
| .MakeGenericMethod(new[] { tType, prop.PropertyType }); | |
| return (IQueryable<T>)sorter | |
| .Invoke(null, new object[] { source, sortLambda }); | |
| } | |
| return source; | |
| } |
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