我有一个基于表单的应用程序.UI由线程处理.从UI线程,我创建3个线程来执行一些处理.
Thread t1 = new Thread(() => performprocessing());
Thread t2 = new Thread(() => performprocessing());
Thread t3 = new Thread(() => performprocessing());
现在,我想在所有3个线程完成执行后在UI线程中执行一个语句.所以,我做了以下事情:
do
{
} while (t1.IsAlive || t2.IsAlive || t3.IsAlive);
/*--execute statement---*/
但我希望UI能够保持响应.在这种情况下,UI线程停留在循环中,直到所有三个线程完成执行.我该怎么做？
我读到了手动和自动重置事件,但我不知道在这种情况下如何使用它们.请指导我.
我有一个说明字段的文件表
DocumentID int - PK and autoincrement
LastStatusChangedDateTime - datetime
JurisdictionID - int
DocumentStatusID - int
现在我想引入一个名为的计算列CanChangeStatus.这就像一个队列.因此,如果文档是第一个,则可以更改其状态.这是我的查询:
Select d.DocumentID,
(
Select Cast(Case When d.DocumentID = v.DocumentID Then 1 Else 0 End as bit)
From
(
Select Top 1 DocumentID
From Documents
Where JurisdictionID = d.JurisdictionID
And
DocumentStatusID = d.DocumentStatusID
Order By LastStatusChangedDateTime
) v
) as CanChangeStatus
From Documents d
指数是那里JurisdictionID和DocumentStatusID.罪魁祸首是子查询 - 我试图计算的方式CanChangeStatus.有什么方法可以加快速度或将此子查询转换为连接,因为连接大多比子查询快？
我正在尝试学习如何根据用户选择的时间来安排图片.
这是带有问题的代码:
private void startjob()
{
string theDate = DateTimePicker1.Value.ToString();
DateTime dt = Convert.ToDateTime(date);
{
DateTime start = new DateTime(2009, 12, 9, 10, 0, 0); //How Do I make this to read the string that is converted from DateTimePicker instead of this?
DateTime end = new DateTime(2009, 12, 10, 12, 0, 0); //How Do I make this to read the string that is converted from DateTimePicker instead of this?
DateTime now = DateTime.Now;
if ((now > start) && (now < …我有以下3个例子,它们做同样的事情
//case1 do it if the condition is valid
private void SetMultiplePropertyValues()
{
if (Keyboard.GetKeyStates(Key.CapsLock) == KeyStates.Toggled)
{
//do somthing
}
}
//case 2 return if the condition is not valid
private void SetMultiplePropertyValues()
{
if (Keyboard.GetKeyStates(Key.CapsLock) != KeyStates.Toggled) return;
//do somthing
}
//case 3 checking the condition in the calling scope
if (Keyboard.GetKeyStates(Key.CapsLock)== KeyStates.Toggled)
SetMultiplePropertyValues())
private void SetMultiplePropertyValues()
{
//do somthing
}
你会选择哪一个？为什么？
我有一个短语输入到类似于此的文本框中:"明天在taree中的天气是什么"
目前,此代码将郊区字符串设置为大写名称,并将suburbID设置为值.
public void requestedSuburb(String suburbFromForm1)
{
suburb = suburbFromForm1;
if (suburb.Contains("taree"))
{
suburb = "Taree";
suburbID = "zmw:00000.1.95784.xml";
}
else if (suburb.Contains("port macquarie"))
{
suburb = "Port Macquarie";
suburbID = "zmw:00000.1.94787.xml";
}
(如果低于此点,则使用else语句检查更多的郊区名称.
将整个InputTextbox.Text传递到郊区字符串以检查上述内容.
我的问题是,是否有一个if语句可以检查郊区字符串,如果没有找到郊区的文本,它可以默认选择？(即:我希望'Taree'成为默认设置.)
我现在拥有的是这个,但它没有返回任何东西:
else if (!suburb.Contains("taree") || (!suburb.Contains("port macquarie")))
{
suburb = "Port Macquarie"
suburbID = "zmw:00000.1.94787.xml";
}
我有以下LINQ查询,我希望数据按totalPopulation降序排列.
var query = from u in xdoc.Root.Elements(ns + "DetailedUtility")
select new
{
UtilityId = (int)u.Attribute("UtilityId"),
TotalPopulation = u.Elements(ns + "City")
.Sum(c => (int)c.Attribute("Population"))
};
如何按降序获取列表.请帮忙
我正在尝试为我的数据表中的每一行运行循环但它给我错误,因为我无法修改每个循环的集合...我还能做些什么来更新表？
我正在尝试删除作为设备名称的单个列的重复条目,如果根据重复的设备名称进行此类选择,则只需更新旧数量.
这是代码:
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
dt = new DataTable();
dt.Columns.Add("Appliance Name", typeof(string));
dt.Columns.Add("Quantity", typeof(int));
dt.Columns.Add("Day Time(Hrs)", typeof(int));
dt.Columns.Add("Backup Time(Hrs)", typeof(int));
// dt.Rows.Add("Sana", 5, 4, 3);
Session["MyDataTable"] = dt;
}
}
protected void BtnAddNext_Click(object sender, EventArgs e)
{
DataTable dtab = (DataTable)Session["MyDataTable"];
if (dtab.Rows.Count != 0)
{
foreach (DataRow r in dtab.Rows)
{
if (Convert.ToString(r["Appliance Name"]) == DDLAppName.Text)
{
int temp = Convert.ToInt32(r["Quantity"]);
r["Quantity"] = Convert.ToInt32(QtyTB.Text) + temp;
} …我正在尝试deserialize从文件中的字符串列表.在这里我的代码
FileStream filestream = new FileStream(@"D:\cache.bin", FileMode.OpenOrCreate);
try
{
BinaryFormatter binformat = new BinaryFormatter();
_cacheFileList = (List<string>)binformat.Deserialize(filestream);
}
catch (SerializationException ex)
{
Console.WriteLine(ex.Message);
}
finally
{
filestream.Close();
}
我收到运行时错误.尝试反序列化空流.
我试图首先在线程内执行代码,并等待for循环完成后再执行for循环后的代码.
for (int i = 254; i > 1; i--)
{
//some code here...
WaitCallback func = delegate (object state)
{
//do something here.... - i want this to finish with the loop first
};
ThreadPool.QueueUserWorkItem(func);
}
// this code is executed once the for loop has finished
// however i want it to be done
// after the thread has finished executing its code and the for loop.
使用 Linq 的 C# 中的 Java 示例的等效项是什么？
int[] someArray(int[] arr1, int[] arr2)
{
return Arrays.stream(arr1).filter(a->Arrays.stream(arr2).noneMatch(i->i == a)).toArray();
}
出于某种原因,我的代码不起作用.我已确认文件夹中有.idx和.log文件.有人可以帮忙吗？
谢谢.
List<string> subDirList = new List<string>(Directory.GetFiles(srcPath, "*"));
if (subDirList.Contains(".idx") && subDirList.Contains(".log"))
{
...
}
遇到一些c#变量的问题.无法弄清楚我做错了什么.可能是一些简单的东西,但我已经有点了.
public class DataFileLoad
{
//Public jagged array variables
public string[][] aConfJag = null;
public string[][] aPartJag = null;
public string[][] aTypeJag = null;
public string[][] aWkshpJag = null;
public string[][] aWorkJag = null;
public void loadFiles()
{
//The path of our exectuable
string exePath = Application.StartupPath;
//Set our working directory to our exe path for file reading
Directory.SetCurrentDirectory(exePath);
string[] aConferences = File.ReadAllLines(@"DATA\CONFERENCES.txt");
string[] aParticipants = File.ReadAllLines(@"DATA\PARTICIPANTS.txt");
string[] aType = File.ReadAllLines(@"DATA\TYPE.txt");
string[] aWkshpReg = File.ReadAllLines(@"DATA\WKSHP_REGISTRATIONS.txt");
string[] aWorkshops = File.ReadAllLines(@"DATA\WORKSHOPS.txt");
//Make …我一直在寻找解决方案,但还没有得到一个坚实的答案.我有VB代码,我需要转换为c#.这是VB代码.我尝试了不同的解决方案,但似乎都没有.这是函数的定义
Protected Sub LoadData(ByVal ProcedureName As String, ByVal NumOuts As Long, ByRef Label1 As Label, Optional ByRef Label2 As Label = Nothing, Optional ByRef Label3 As Label = Nothing)
Dim ConnStr As String
ConnStr = "Data Source=H50;Initial Catalog=" + Me.DatabaseName.Text + ";Integrated Security=True"
Dim conn As New SqlConnection(ConnStr).....
这是要求这一点的众多功能之一
Protected Sub LoadtblStaffContactsBtn_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles LoadtblStaffContactsBtn.Click
LoadData("Load_tblStaffContacts", 2, Me.tblStaffContacts_Label1, Me.tblStaffContacts_Label2)
Me.LoadtblStudentBtn.Enabled = True
End Sub