DataTable 中的过滤不适用于 DateTime.Now 或 DateTime.AddDays

Question

我正在尝试过滤 DataTable 中的 DateTime 并遇到一个奇怪的过滤问题。

1) 数据和过滤 - 工作正常

public DataTable GetDataTable()
{
DataTable employeeCollection = new DataTable();
var dt = DateTime.Now;

employeeCollection.Columns.Add("EmployeeID", typeof(int));
employeeCollection.Columns[0].ColumnName = "Employee ID";
employeeCollection.Columns.Add("EmployeeName", typeof(string));
employeeCollection.Columns["EmployeeName"].ColumnName = "Employee Name";
employeeCollection.Columns.Add("CustomerID", typeof(string));
employeeCollection.Columns["CustomerID"].ColumnName = "Customer ID";
employeeCollection.Columns.Add("Country", typeof(string));
employeeCollection.Columns.Add("Date", typeof(DateTime));

DateTime date1 = new DateTime(2011, 6, 26, 4, 34, 45);
DateTime date2 = new DateTime(2011, 6, 27, 4, 34, 45);

employeeCollection.Rows.Add(1011, "DintinAmam", "Alfki", "Britain", date1);
employeeCollection.Rows.Add(1012, "JohnAmam", "Johanesberg", "China", date2);

string filterString = "Date = #" + date1.ToString() + "#";

employeeCollection.DefaultView.RowFilter = filterString;

return employeeCollection;
}

过滤字符串 - “日期 = #6/26/2011 4:34:45 AM#”

输出 1：

2) 数据和过滤 - 不起作用

public DataTable GetDataTable()
{
DataTable employeeCollection = new DataTable();
var dt = DateTime.Now;

employeeCollection.Columns.Add("EmployeeID", typeof(int));
employeeCollection.Columns[0].ColumnName = "Employee ID";
employeeCollection.Columns.Add("EmployeeName", typeof(string));
employeeCollection.Columns["EmployeeName"].ColumnName = "Employee Name";
employeeCollection.Columns.Add("CustomerID", typeof(string));
employeeCollection.Columns["CustomerID"].ColumnName = "Customer ID";
employeeCollection.Columns.Add("Country", typeof(string));
employeeCollection.Columns.Add("Date", typeof(DateTime));

DateTime date1 = DateTime.Now.AddDays(1);
DateTime date2 = DateTime.Now.AddDays(2);

employeeCollection.Rows.Add(1011, "DintinAmam", "Alfki", "Britain", date1);
employeeCollection.Rows.Add(1012, "JohnAmam", "Johanesberg", "China", date2);

string filterString = "Date = #" + date1.ToString() + "#";

employeeCollection.DefaultView.RowFilter = filterString;

return employeeCollection;
}

过滤字符串 - “日期 = #6/27/2018 5:19:17 PM#”

输出 2：

使用构造函数创建 DateTime 值时，过滤工作正常，而使用 DateTime.Now 过滤时不起作用。

谁能确认一下，为什么使用 DateTime.Now.AddDays() 初始化 Date 值对过滤不起作用？

Answer 1

日期/时间值的行过滤器处理亚秒组件（毫秒...）。

但日期/时间的默认格式不包括这些。

您的过滤器仅在 date1 和 date2 没有亚秒组件时才起作用，这是您的第一个代码 sn-p 中的情况（此 DateTime 构造函数将它们设置为 0）。

一种解决方案是给ToString 一个包含亚秒组件的格式。