C# Discussion Boards - CodeProject

setting time on Zip Entry

11-May-04 16:21

Trust me - using parameters is so much better. You can add them programmatically, as there is no other way! Smile | :)

For example (and I'm assuming you're using an OleDbCommand since you're using # signs):

OleDbCommand cmd = oleDbConnection.CreateCommand();
cmd.CommandText = "SELECT * FROM MyTable WHERE DateCol BETWEEN ? AND ?";
cmd.Parameters.Add("StartDate", OleDbType.DBDate).Value = DateTime.Parse("5/4/04");
cmd.Parameters.Add("EndDate", OleDbType.DBDate).Value = DateTime.Parse("5/11/04");
OleDbDataReader reader = null;
try
{
  oleDbConnection.Open();
  reader = cmd.ExecuteReader();
  // ...
}
catch (Exception e)
{
  Console.Error.WriteLine(e.Message);
}
finally
{
  if (reader != null) reader.Close();
  oleDbConnection.Close();
}

Of course, you could use this command with an OleDbDataAdapter as well - this is just an example.

Still, though it is unusual that it's treating it as a string. You're not using quotes and # signs, are you?

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Re: Query, DateTime

DougW4811-May-04 16:47

DougW48

11-May-04 16:47

I'll give this a try and see if it makes a difference. And no, I just have the hash signs, not the single quotes. The message I replied after the other person's post is a direct copy and paste.

Re: Query, DateTime

DougW4811-May-04 18:07

DougW48

11-May-04 18:07

I'm pretty embarrassed to admit this, but I discovered that the date column in my database was set to text. At any rate, I did convert things to parameters, so your efforts weren't in vain. Thanks for the help!

elena1234511-May-04 8:09

elena12345

11-May-04 8:09

I am zipping up a bunch of files and "Modified" date on the files always turns out to be 1/1/1980 12:00AM
The date I have is in DateTime format, and I tried
zipEntry.setDate(d.ToFileTimeUtc())
zipEntry.setDate(d.ToFileTimeUtc())
zipEntry.setDate(d.ToFileTime())
zipEntry.setDate(d.Ticks)
Nothing works!!! It keeps on getting 1/1/1980 12:00AM

Do you have any idea why this is not working?
Code:

<br />
<br />
ZipEntry currententry = new ZipEntry(localPath);<br />
currententry.setMethod(ZipEntry.DEFLATED);                                <br />
currententry.setTime(createDate.ToFileTimeUtc());                  <br />
<br />
m_zipstream.putNextEntry(currententry);                <br />
                <br />
try<br />
{                    <br />
   java.io.FileInputStream current = new java.io.FileInputStream(fullPath);                    <br />
   try<br />
   {<br />
     sbyte[] buffer = new sbyte[8192];<br />
     int     buffercount;<br />
 <br />
     while ((buffercount = current.read(buffer, 0, buffer.Length)) > 0)<br />
       m_zipstream.write(buffer, 0, buffercount);                                                <br />
   }<br />
   finally { current.close(); }                    <br />
}<br />
finally { m_zipstream.closeEntry(); }<br />

Thanks,

Elena

Jeff Varszegi11-May-04 9:00

11-May-04 9:00

Apparently, there are bugs in the J# zip library; check out this recent post by Nish:

Bug when using the java.util.zip classes to write zip files

Several people recommended SharpZipLib, about which I've also heard good things.

-Jeff

Heath Stewart11-May-04 9:20

11-May-04 9:20

I've heard that too (and I see I'm mentioned Blush | :O

). In this case, however, is sounds like an epoch problem since Java and .NET (not to mention the OLE DATE and who knows what else) all use different epochs. The DateTime struct in .NET also uses ticks (100 ns) instead of ms like most structs. And developers thought all the different text encodings were a problem! Roll eyes | :rolleyes:

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Jeff Varszegi12-May-04 6:58

12-May-04 6:58

I never even used J#, but you could be right. I didn't know that they actually replicated the Java classes like DateTime that have equivalents in C#, but it does make sense. In any case, the poster'd probably be MUCH better off using SharpZipLib...

Heath Stewart12-May-04 7:38

12-May-04 7:38

The didn't. The java.util.Date is nothing like the DateTime. The J# portability assemblies work just like the Java classes. Encapsulating a DateTime in a Date, for example, would screw-up any code that modifies the Date.

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Heath Stewart11-May-04 9:10

11-May-04 9:10

DateTime in .NET and the date and time in Java use different epochs (start times). DateTime is the number of ticks from 00:00:00 Jan. 1, 0001 AD. Java's Date starts at 00:00:00 Jan. 1, 1970 AD and is the number of milliseconds from that date/time.

A tick is 100 nanoseconds. So, to convert a DateTime to the number of milliseconds to use, you'll need to take this information into account and convert the number.

The best way is to use the java.util.Date class. When working with the vjslib.dll assembly, keep in mind that this assembly exists only to make it easier for Java developers to make the move. It's intended to work just like it would if you were still developing with Java classes. Classes in the FCL and Java assemblies should not be inter-mixed without proper consideration.

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elena1234511-May-04 11:10

elena12345

11-May-04 11:10

Is java.util.Date a part of vjslib or is it from a different library?

Thanks for your help.

Elena

Heath Stewart11-May-04 11:13

11-May-04 11:13

Yes it's in the vjslib.dll assembly, along with pretty much everything else you'd find in the JRE (besides the swing stuff). If you want to know for sure, run ildasm.exe (the IL Disassembler found in the .NET Framework SDK bin directory) and open the vjslib.dll assembly in the %WINDIR%\Microsoft.NET\Framework\v1.1.4322 directory. This will show you the assembly and Type metadata, as well as the IL for any module(s) in the assembly (if you know how to read IL).

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popup tip on form

cchere11-May-04 8:02

cchere

11-May-04 8:02

How can I display a popup tip when the mouse moves over a certain area on a form?

Help class can show popup tips but I cannot hide the tip when I am done with it. Any suggestion?

Thanx

Re: popup tip on form

Heath Stewart11-May-04 8:54

11-May-04 8:54

A simple hack would be to put a Panel in that region of the form and use the ToolTip component to set the tooltip for that region. The ToolTip is an IExtenderProvider that provides "properties" to other controls. Once you add it, click on that Panel and you'll see something like "ToolTip on panel1" (or whatever you call your panel variable).

The other way is to P/Invoke SendMessage and send the tooltip common control messages, which is really all the ToolTip component is doing. You can use the Form.MouseHover event to determine when to show the tooltip.

You can find out more about the tooltip common control and it's messages in the Platform SDK: http://msdn.microsoft.com/library/en-us/shellcc/platform/commctls/tooltip/reflist.asp[^].

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Re: popup tip on form

cchere13-May-04 12:32

cchere

13-May-04 12:32

Great ideas. Thanks a lot.

Rounded numbers in C#

spyforcer11-May-04 5:51

spyforcer

11-May-04 5:51

I meet with one problem in C# : when double convert to int
If value is halfway between two whole numbers, the even number is returned; that is, 4.5 is converted to 4, and 5.5 is converted to 6.
In MSDN it is circumscribed as correct operation, well and when a classical understanding of math operation
round (5.5) == 6 and round (5.4) == 5. I think that the Microsoft imposes the understanding of roundoff of numbers.
Would like to hear your judgements concerning...

Jeff Varszegi11-May-04 6:35

11-May-04 6:35

Well, I've always viewed a cast that discards specificity as a truncation of sorts. The semantics of casting from double to int are what I'd expect of a truncation routine, so I'm not unhappy with it. How about something like this for your needs?

<br />
   public static int Round(double d) {<br />
       if (d >= 0) {<br />
           return ((int)(d + 0.5D));<br />
       }<br />
       else {<br />
           return ((int)(d - 0.5D));<br />
       }<br />
   }<br />

-Jeff

here, bloggy bloggy

spyforcer11-May-04 21:02

spyforcer

11-May-04 21:02

Thank Jeff for your answer, I yesterday have written approximately same function.

Jeff Varszegi12-May-04 6:57

12-May-04 6:57

You're welcome.

Heath Stewart11-May-04 6:40

11-May-04 6:40

This is a known issue (it's been discussed a few other times here on CodeProject as well), but not necessarily a bug (though one could argue it is). There's a lot of information about this on the web. Take a look at this one I grabbed from google: http://weblogs.asp.net/sfurman/archive/2003/03/07/3537.aspx[^].

Basically, it all comes down to precision. The article above has a link to some of the documentation in the .NET Framework SDK that indicates as much. There's also a cludgy work-around if you want to use that instead (using SqlDecimal.Round).

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