我对c#和数据库
连接不熟悉,因此无法通过搜索stackoverflow的旧帖子来获得这个。
类似代码
private void issueDetails()
{
string connectionPath = @"Data Source=Data\libraryData.dat;Version=3;New=False;Compress=True";
using (SQLiteConnection connection = new SQLiteConnection(connectionPath))
{
SQLiteCommand command = connection.CreateCommand();
connection.Open();
string query = "SELECT bookno as 'Book No.',studentId as 'Student ID', title as 'Title', author as 'Author', description as 'Description', issuedDate as 'Issued Date', dueDate as 'Due Date' FROM issuedBooks";
command.CommandText = query;
command.ExecuteNonQuery();
SQLiteDataAdapter da = new SQLiteDataAdapter(command);
DataSet ds = new DataSet();
da.Fill(ds, "issuedBooks");
dataGridView1.DataSource = ds.Tables["issuedBooks"];
dataGridView1.Sort(dataGridView1.Columns["Student ID"], ListSortDirection.Ascending);
dataGridView1.ReadOnly = true;
connection.Close();
}
}
我曾使用上述代码来获取一些图书馆书籍的详细信息,例如借出日期和应还日期。现在,我想要突出显示一个特定的单元格,即超过了应还日期的单元格。
private void dataGridView1_CellFormatting(object sender, DataGridViewCellFormattingEventArgs e)
{
Color c = Color.Black;
if (e.ColumnIndex == 6)
{
if (isLate(Convert.ToString(e.Value)))
{
c = Color.Red;
count++;
Console.WriteLine(count);
}
}
e.CellStyle.ForeColor = c;
}
public string toInd(string date)
{
DateTimeFormatInfo fmt = new CultureInfo("fr-fr").DateTimeFormat;
string dateString;
DateTimeOffset offsetDate, dateig;
string ret = DateTime.Now.ToShortDateString();
dateString = date;
bool ws = DateTimeOffset.TryParse(dateString, fmt, DateTimeStyles.None, out dateig);
if (ws)
{
offsetDate = DateTimeOffset.Parse(dateString, fmt);
ret = offsetDate.Date.ToShortDateString();
return ret;
}
return ret;
}
private bool isLate(string nowS)
{
DateTime dueDate = Convert.ToDateTime(toInd(nowS));
DateTime now;
string present = DateTime.Now.ToShortDateString();
now = Convert.ToDateTime(present);
//Console.WriteLine(toInd(nowS));
int a = dueDate.CompareTo(now);
if (a >= 0)
return false;
else return true;
}
但是如果使用if (isLate(Convert.ToString(e.Value)))
{
c = Color.Red;
count++;
Console.WriteLine(count);
}
来计算逾期的书籍数量,即使我的数据库中只有两本书过期,这个'count'值会增加4次,因为在数据绑定时这个if块被访问了2次,排序时又被访问了2次。我该如何得到仅逾期书籍数量的值?