DataGrid显示的时间为什么没有“时、分、秒”？——WinForm中对DataGrid应用样式

SqlConnection conn = new SqlConnection( "server=(local);Database=prjmaster;uid=sa;pwd=123456" );
SqlDataAdapter da = new SqlDataAdapter( "SELECT TOP 10 * FROM Bug", conn );
DataSet ds = new DataSet();
try
{
da.Fill( ds, "BugTable" );
}
catch( Exception ex )
{
MessageBox.Show( ex.Message );
}
dataGrid1.DataSource = ds.Tables["BugTable"];

CurrencyManager myCurrencyManger = //获取对象列表管理器
(CurrencyManager)this.BindingContext[ds];

DataGridTableStyle myTableStyle = new DataGridTableStyle(); //创建表样式
myTableStyle.MappingName = "BugTable";

PropertyDescriptor myDateDescriptor = //获取包含日期的列的PropertyDescriptor
myCurrencyManger.GetItemProperties()["bugopendate"];

// 'G' is for MM/dd/yyyy HH:mm:ss date format.
DataGridColumnStyle myDateStyle = //创建列样式
new DataGridTextBoxColumn(myDateDescriptor,"G");

myDateStyle.MappingName = "bugopendate"; //数据库中的列名
myDateStyle.HeaderText = "Bug Open Date"; //要显示在DataGird表头上的文字
myDateStyle.Width = 150; //宽度

/如果你想显示多个列，就要生成多个DataGridColumnStyle对象/
DataGridColumnStyle column2 = new DataGridTextBoxColumn();
column2.MappingName = "bugassignto";
column2.HeaderText = "Bug接收者";

myTableStyle.GridColumnStyles.Add(myDateStyle); //加入列样式
myTableStyle.GridColumnStyles.Add(column2);

dataGrid1.TableStyles.Add(myTableStyle); //将表样式加入DataGrid