microsoft.public.dotnet.languages.csharp Latest Posts

Re: A very small complete program that doesn't work as expected

Sat, 04 Jul 2009 08:26:10 -0400

Tony Johansson wrote:
> Hello!
>
> I have a complete program listed below that use the northwind database table
> Customers.
> I have one control in the form and that is a DataGridView called
> dataGridViewCustomer.
> I use a SqlDataAdapter that pass the sql statement Select * from customers
> in the c-tor.
> When I run in the debugger I can see that the DataSet thisDataSet contains
> all the rows that should be displayed
> in the DataGridView but nothing is being displayed.
>
> As you can see I set the DataSource for the DataGridView to the DataSet
> thisDataSet.
> I event to a refresh() on the DataGridView but nothing helps.
>
> So does anyone know why my DataGridView doesn't display the contents of the
> DataSet ?
>

> public partial class Form1 : Form
> {
> public Form1()
> {
> InitializeComponent();
>
> SqlConnection thisConnection = new SqlConnection();
> thisConnection.ConnectionString = "Integrated Security=true;" +
> "Initial Catalog=Northwind;" +
> "Data Source=hempc\\SQLExpress";
> DataSet thisDataSet = new DataSet();
> SqlDataAdapter custAdapter = new SqlDataAdapter
> ("Select * from customers", thisConnection);
> custAdapter.Fill(thisDataSet, "Customers");
> this.dataGridViewCustomer.DataSource = thisDataSet;
> this.dataGridViewCustomer.Refresh();
> }
> }
>

> //Tony
>
>

I changed your code to the following after noticing the returned table
name was not "Customers", but was "Table" in the dataset.

DataSet thisDataSet = new DataSet();
SqlDataAdapter custAdapter =
new SqlDataAdapter("Select * from customers", thisConnection);
custAdapter.Fill(thisDataSet);
this.dataGridViewCustomer.DataSource = thisDataSet.Tables[0];

--------------------
Mike

A very small complete program that doesn't work as expected

Sat, 04 Jul 2009 11:10:17 GMT

Hello!

I have a complete program listed below that use the northwind database table
Customers.
I have one control in the form and that is a DataGridView called
dataGridViewCustomer.
I use a SqlDataAdapter that pass the sql statement Select * from customers
in the c-tor.
When I run in the debugger I can see that the DataSet thisDataSet contains
all the rows that should be displayed
in the DataGridView but nothing is being displayed.

As you can see I set the DataSource for the DataGridView to the DataSet
thisDataSet.
I event to a refresh() on the DataGridView but nothing helps.

So does anyone know why my DataGridView doesn't display the contents of the
DataSet ?

//Here is the program
using System;
using System.ComponentModel;
using System.Data;
using System.Windows.Forms;
using System.Data.SqlClient;
static class Program
{
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new Form1());
}
}

public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();

SqlConnection thisConnection = new SqlConnection();
thisConnection.ConnectionString = "Integrated Security=true;" +
"Initial Catalog=Northwind;" +
"Data Source=hempc\\SQLExpress";
DataSet thisDataSet = new DataSet();
SqlDataAdapter custAdapter = new SqlDataAdapter
("Select * from customers", thisConnection);
custAdapter.Fill(thisDataSet, "Customers");
this.dataGridViewCustomer.DataSource = thisDataSet;
this.dataGridViewCustomer.Refresh();
}
}

partial class Form1
{
private System.ComponentModel.IContainer components = null;
protected override void Dispose(bool disposing)
{
if (disposing && (components != null))
{
components.Dispose();
}
base.Dispose(disposing);
}

#region Windows Form Designer generated code
private void InitializeComponent()
{
this.dataGridViewCustomer = new
System.Windows.Forms.DataGridView();
((System.ComponentModel.ISupportInitialize)(this.dataGridViewCustomer)).BeginInit();
this.SuspendLayout();
this.dataGridViewCustomer.ColumnHeadersHeightSizeMode =
System.Windows.Forms.DataGridViewColumnHeadersHeightSizeMode.AutoSize;
this.dataGridViewCustomer.Location = new System.Drawing.Point(25,
24);
this.dataGridViewCustomer.Name = "dataGridViewCustomer";
this.dataGridViewCustomer.Size = new System.Drawing.Size(506, 342);
this.dataGridViewCustomer.TabIndex = 0;
this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
this.ClientSize = new System.Drawing.Size(543, 408);
this.Controls.Add(this.dataGridViewCustomer);
this.Name = "Form1";
this.Text = "Form1";
((System.ComponentModel.ISupportInitialize)(this.dataGridViewCustomer)).EndInit();
this.ResumeLayout(false);
}
#endregion
private System.Windows.Forms.DataGridView dataGridViewCustomer;
}

//Tony

Re: Setting and Retrieving MySQL BIT(1) datatype as boolean value

Sat, 04 Jul 2009 10:51:27 +0100

ng01@gvn.com wrote:
> What would the proper parameter statement be to insert a true or false
> into a MySQL (version 5.1.31) BIT(1) field? Here is what I have:
>
> Cmd.Parameters.Add("@USCurrency", OdbcType.Bit).Value = 0;
>
> And what would be the proper select statement to retrieve a true or
> false from that field?
> Here is what I'm trying, but it always returns a True (when I browse
> the datatable in the debugger):
>
> DataTable dt = GetTable2("select USCurrency from tblquotesnew");
>
> I've tried every OdbcType, with various values, both numeric and
> string, to no avail. It always comes back True.
>
> Thanks very much for any ideas.

Try DataTable dt = GetTable2("select USCurrency from tblquotesnew where
USCurrency = 1");

Setting and Retrieving MySQL BIT(1) datatype as boolean value

ng01@gvn.com — Sat, 4 Jul 2009 00:47:11 -0700 (PDT)

What would the proper parameter statement be to insert a true or false
into a MySQL (version 5.1.31) BIT(1) field? Here is what I have:

Cmd.Parameters.Add("@USCurrency", OdbcType.Bit).Value = 0;

And what would be the proper select statement to retrieve a true or
false from that field?
Here is what I'm trying, but it always returns a True (when I browse
the datatable in the debugger):

DataTable dt = GetTable2("select USCurrency from tblquotesnew");

I've tried every OdbcType, with various values, both numeric and
string, to no avail. It always comes back True.

Thanks very much for any ideas.

Re: Styling controls

Sat, 4 Jul 2009 07:06:20 +0000

Many are created as user controls and using GDI+ among other things

"Sweetiecakes" wrote in message
news:4a4e3251$0$26363$9b536df3@news.fv.fi:

> Hi
>
> How are packages like DotNetBar and such created? I'd like to have a
> better looking TreeView, but I don't think I'm very willing to dish out
> 800$ on one...
>
> How are those controls created?

Re: a simple client example

Fri, 03 Jul 2009 23:11:27 -0700

On Fri, 03 Jul 2009 21:29:16 -0700, Andreas Ott
wrote:

> Good morning,
>>> My is not working.
>>>
>>> Every time I receive a exception.
>>> catch (Exception e)
>>> {
>>> Console.WriteLine(e.Message);
> here!

No. That's where the exception is _caught_, not thrown.

>>> }
>> What exception ? In what line ?
>>
>
> Message "No connection"
> ErrorCode 10061 int

Just looking at the code, I'd say one possible problem is that you don't
understand the NetworkStream.Read() method. In particular, while your
first comment states correctly that the return value will be "anything
from 0 to numBytesToRead", the second comment incorrectly states that the
"method blocks until at least one byte is read", and you fail to check for
a 0 return value, indicating the end-of-stream.

And if you try to read from a socket once it's reached the end-of-stream,
it's entirely possible you'd get the "no connection" exception you're
seeing.

If that doesn't help you fix your code, then you need to provide a more
complete example. In particular, seeing the client side code isn't
sufficient; there's no way to be sure we can reproduce the problem unless
you provide enough information to use that client code with some specific
server. I.e. either provide the server code itself, or provide the
necessary command line arguments that one would require in order to
connect to an appropriate server.

Pete

Re: a simple client example

Sat, 04 Jul 2009 06:29:16 +0200

Good morning,
>> My is not working.
>>
>> Every time I receive a exception.
>> catch (Exception e)
>> {
>> Console.WriteLine(e.Message);
here!
>> }
>
> What exception ? In what line ?
>

Message "No connection"
ErrorCode 10061 int

Regards Andreas

Re: a simple client example

Fri, 03 Jul 2009 20:45:53 -0400

Andreas Ott wrote:
> I looking for a simple client example.
> My is not working.
>
> Every time I receive a exception.
> catch (Exception e)
> {
> Console.WriteLine(e.Message);
> }

What exception ? In what line ?

Arne

Re: Styling controls

Fri, 3 Jul 2009 19:26:25 -0500

I don't know, I'm very ignorant, what anbout silverligth?

I hope my comment could be useful for something

"Sweetiecakes" escribis en el mensaje
news:4a4e3251$0$26363$9b536df3@news.fv.fi...
> Hi
>
> How are packages like DotNetBar and such created? I'd like to have a
> better looking TreeView, but I don't think I'm very willing to dish out
> 800$ on one...
>
> How are those controls created?

Communication with threads

Sat, 4 Jul 2009 01:48:41 +0200

Hello NG

I have found some code about TAPI, this set me going to implement TAPI in my
Application.
The TAPI i made in two classes within my application.
The Main Class TAPIComponent initializes the Tapi (Using the Microsoft
Tapi3) and the second class is the Event class for the TAPIComponent.

On The Event class i have a Delegate DetectCallHandler(string CallerID) and
DetectCall Event that is called from the TAPIComponent.
On the TAPIComponent I have a Delegate IncommingCallHandler(string CallerID)
and IncommingCall Event, that is called within my Application - like

TAPIComponent tapiCom = new TAPIComponent();
tapiCom.IncommingCall += new
TAPIComponent.IncommingCallHandler(tapi_IncommingCall);

So, when the TAPI device detect a call i raises the event DetectCall - in
that event the event IncommingCall is raised and by that i'll get the caller
id into my application.

All above works just fine.

In my application in the event tapi_IncommingCall I want to display a
winform (TAPINotify) with information on the CallerID, and some buttons that
opens other winforms.

Already when I want to open the TAPINotify form is gets (not responding) and
if i open the form with the parameter TAPINotify.MDIParent = DesktopForm
i'll get the exception about not able to open form from other thread?
Then I tryed to open that TAPINotify in another Thread - OK fine it worked.
But now when i wanted to open forms from the TAPINotify form i'll got the
same error from before, because the form i open must have the MDIParent set
to my desktop form.

Can someone tell me what to do.

Kind regards
J E Jensen

Re: GZipStream catch-22

Fri, 03 Jul 2009 19:07:07 -0400

bamelyan wrote:
> GZipStream unzip = new GZipStream(stream, CompressionMode.Decompress, false);
>
> In order to read from unzip.Read(buffer, 0, unknownLength), I need to
> allocate enough buffer length.
> In order to know how many bytes to allocate I need to call
> unzip.Read(buffer, 0, unknownLength) that returns bytes.
>
> How do i get unknownLength to allocate buffer before the Read?

Just pick a buffer size (like 51200) and read in a while
loop and process the data as they come in.

If you need to keep all the data in a buffer in memory, then
you will need to either know the maximum size or copy over
to a larger buffer when needed.

You can know how many bytes if the protocol somehow sends
the uncompressed length before the gzipped data.

If the data is "normal", then creating a buffer 10 times as
big as the compressed data and copy to a new larger buffer
inside the while loop if necessary should be fine in the sense
that the chance of having to copy data would be very small.

Arne

Re: Is MemoryStream compressed?

Fri, 03 Jul 2009 19:02:51 -0400

bamelyan wrote:
> "Arne VajhC8j" wrote:
>> bamelyan wrote:
>>> Is there a way to determine wether a MemoryStream is compressed, i.e. needs
>>> to be decompressed with GZipStream?
>> Not really.
>>
>> Bytes are just bytes.
>>
>> If the first 3 bytes are 0x1f 0x8b 0x08 then there is a decent chance
>> it is gzipped.
> thanks for quick response. what's the expected behavior of
GZipStream if i
> try to decompress a stream that is not compressed?

I think one of two will happen:
* if the data just happens to be a valid GZIP format then you
will get absolute garbage
* else (and that is by far the most likely) then you will
get a InvalidDataException

Arne

Re: GZipStream catch-22

Sat, 04 Jul 2009 00:05:45 +0200

bamelyan wrote:
> GZipStream unzip = new GZipStream(stream, CompressionMode.Decompress, false);
>
> In order to read from unzip.Read(buffer, 0, unknownLength), I need to
> allocate enough buffer length.
> In order to know how many bytes to allocate I need to call
> unzip.Read(buffer, 0, unknownLength) that returns bytes.
>
Not at all. Any buffer size that's not 0 will do. The Read() method returns
the number of bytes actually read. If it's 0, you're at the end of the
stream. If not, your buffer contains valid data from index 0 up to whatever
it returned (this may not fill your buffer entirely, even when not at the
end of the stream). Process this data in whatever way you want (for example,
by appending it to a MemoryStream you're going to read in its entirety
later), rinse, repeat.

All streams work this way, not just GZipStream.

> How do i get unknownLength to allocate buffer before the Read?

Pick any length. Let's say 1024 because it's a nice round number, and it's
what BufferedStream uses by default. (Using BufferedStream and .ReadByte()
is another option -- not as efficient as calling .Read() yourself, but by
far more efficient than calling .ReadByte() on GZipStream directly.)

--
J.

Re: GZipStream catch-22

Fri, 03 Jul 2009 17:55:01 -0400

GZipStream catch-22

Fri, 3 Jul 2009 14:44:01 -0700

GZipStream unzip = new GZipStream(stream, CompressionMode.Decompress, false);

In order to read from unzip.Read(buffer, 0, unknownLength), I need to
allocate enough buffer length.
In order to know how many bytes to allocate I need to call
unzip.Read(buffer, 0, unknownLength) that returns bytes.

How do i get unknownLength to allocate buffer before the Read?

Re: Is MemoryStream compressed?

Fri, 3 Jul 2009 14:31:01 -0700

thanks for quick response. what's the expected behavior of GZipStream if i
try to decompress a stream that is not compressed?

"Arne VajhC8j" wrote:

> bamelyan wrote:
> > Is there a way to determine wether a MemoryStream is compressed, i.e. needs
> > to be decompressed with GZipStream?
>
> Not really.
>
> Bytes are just bytes.
>
> If the first 3 bytes are 0x1f 0x8b 0x08 then there is a decent chance
> it is gzipped.
>
> Arne
>

Re: Is MemoryStream compressed?

Fri, 03 Jul 2009 16:45:04 -0400

bamelyan wrote:
> Is there a way to determine wether a MemoryStream is compressed, i.e. needs
> to be decompressed with GZipStream?

Not really.

Bytes are just bytes.

If the first 3 bytes are 0x1f 0x8b 0x08 then there is a decent chance
it is gzipped.

Arne

a simple client example

Fri, 03 Jul 2009 22:43:08 +0200

Hello,

I looking for a simple client example.
My is not working.

Every time I receive a exception.
catch (Exception e)
{
Console.WriteLine(e.Message);
}

My goal is.
I need a client for receive data, without limit for logging.
The client is / must be every time on state --- receive

Can somebody help me.

Thanks.

Regards
Andreas

class Program
{
static void Main(string[] args)
{
if ((args.Length < 1) || (args.Length > 3))
{
throw new ArgumentException("Parameters:
[] []");
}

byte[] byteBuffer = Encoding.ASCII.GetBytes(args[0]);

string server = (args.Length == 1) ? args[0].ToString() :
Dns.GetHostName();

int servPort = (args.Length == 2) ? Int32.Parse(args[1]) : 7;

TcpClient tcpClient = null;
NetworkStream netStream = null;

try
{
tcpClient = new TcpClient(server, servPort);

// Uses the GetStream public method to return the
NetworkStream.
netStream = tcpClient.GetStream();

//if (netStream.CanWrite)
//{
// Byte[] sendBytes = Encoding.UTF8.GetBytes("Is
anybody there?");
// // netStream.Write(sendBytes, 0, sendBytes.Length);
//}
//else
//{
// Console.WriteLine("You cannot write data to this
stream.");
// tcpClient.Close();

// // Closing the tcpClient instance does not close
the network stream.
// netStream.Close();
// return;
//}

while (true)
{
if (netStream.CanRead)
{
// Reads NetworkStream into a byte buffer.
byte[] bytes = new
byte[tcpClient.ReceiveBufferSize];

// Read can return anything from 0 to
numBytesToRead.
// This method blocks until at least one byte
is read.
netStream.Read(bytes, 0,
(int)tcpClient.ReceiveBufferSize);

// Returns the data received from the host to
the console.
string returndata =
Encoding.UTF8.GetString(bytes);

Console.WriteLine("This is what the host
returned to you: " + returndata);

}
}
//else
//{
Console.WriteLine("You cannot read data from this
stream.");
tcpClient.Close();

// Closing the tcpClient instance does not close
the network stream.
netStream.Close();
return;
//}
//netStream.Close();
}
catch (Exception e)
{
Console.WriteLine(e.Message);
}
finally
{

}
}
}

Re: ASCII to hex/binary

Fri, 03 Jul 2009 16:17:57 -0400

TNCoder wrote:
> I have an ASCII string. For example:
> string myString = "1200B2C4D2BB9863";
> I need to convert this to byte[] 0x1200B2C4D2BB9863;
>
> Are there any suggestions?

Straight:

public static byte[] XParse(string s)
{
byte[] ba = new byte[s.Length / 2];
for(int i = 0; i < ba.Length; i++)
{
ba[i] = byte.Parse(s.Substring(2 * i, 2),
NumberStyles.HexNumber);
}
return ba;
}

Arne

Re: get current platform (x86, x64)

Fri, 03 Jul 2009 16:09:50 -0400

Family Tree Mike wrote:
> Michael Covington wrote:
>> Frank Uray wrote:
>>> I am using "Any CPU" within my assemblies.
>>> Is there a way to find out which platform is used ?
>>> I like to know where the assembly is running on (x86, x64) ...
>>>
>>> Thanks for any comments
>>> and best regards
>>> Frank Uray
>>
>> If nothing else, there should be a WMI call to tell you about this.
>> For something related, see:
>>
>> http://www.covingtoninnovations.com/michael/blog/0807/index.html#080710
>>
>> However, there may be a way to do it within .NET. Ideas, anyone?
>
> The size of IntPtr will be 8 under x64, and 4 under x86.
>
> Console.WriteLine(IntPtr.Size == 4 ? "x86" : "x64");

Assuming that it is 32/64 bit of the CLR and not of Windows, then
that must be the easiest.

Arne