20210816

SGGL/BLL/SortConditionHelper.cs

@@ -0,0 +1,38 @@
+using System;
+using System.Linq;
+using System.Linq.Expressions;
+using System.Reflection;
+
+namespace BLL
+{
+    public static class SortConditionHelper
+    {
+        public static IQueryable<T> DataSorting<T>(IQueryable<T> source, string sortExpression, string sortDirection)
+        {
+            string sortingDir = string.Empty;
+            if (sortDirection.ToUpper().Trim() == "ASC")
+                sortingDir = " OrderBy ";
+            else if (sortDirection.ToUpper().Trim() == "DESC")
+                sortingDir = " OrderByDescending ";
+            ParameterExpression param = Expression.Parameter(typeof(T), sortExpression);
+            PropertyInfo pi = typeof(T).GetProperty(sortExpression);
+            Type[] types = new Type[2];
+            types[0] = typeof(T);
+            types[1] = pi.PropertyType;
+            Expression expr = Expression.Call(typeof(Queryable), sortingDir, types, source.Expression, Expression.Lambda(Expression.Property(param, sortExpression), param));
+            IQueryable<T> query = source.AsQueryable().Provider.CreateQuery<T>(expr);
+            return query;
+        }
+
+        public static IQueryable<T> DataPaging<T>(IQueryable<T> source, int pageNumber, int pageSize)
+        {
+            return source.Skip(pageNumber * pageSize).Take(pageSize);
+        }
+
+        public static IQueryable<T> SortingAndPaging<T>(IQueryable<T> source, string sortExpression, string sortDirection, int pageNumber, int pageSize)
+        {
+            IQueryable<T> query = DataSorting<T>(source, sortExpression, sortDirection);
+            return DataPaging(query, pageNumber, pageSize);
+        }
+    }
+}