Re: Linq question, error I do not understand - C# Discussion Boards

manustone24-Nov-09 2:47

24-Nov-09 2:47

Hi Harold!
Thanks for your email!
It is true and in the code I am writing I am actually using boolean.
It is consistent to what stated in MSDN so it doesn't compile.
Maybe it is a stupid question but do you know why?

Re: Surprise!

harold aptroot24-Nov-09 3:19

harold aptroot

24-Nov-09 3:19

Well, I wouldn't claim to know for sure, but I could hazard a guess..
At least on x86 in 32bit mode (but maybe 64bit mode as well, not sure?), as far as I know, the only way to do atomic stores/loads of 64bit is through lock cmpxchg8b (with zero in all* registers). It would have been possible for them to implement volatile longs that way, I guess they just didn't feel like it - maybe they felt it wouldn't be worth the effort?

* EDX:EAX and ECX:EBX, that's not really "all registers" but pretty close

i have problem axShockwaveFlash1_OnProgress [modified]

bekzod00923-Nov-09 19:14

bekzod009

23-Nov-09 19:14

<br />
using System;<br />
using System.Drawing;<br />
using System.Collections;<br />
using System.ComponentModel;<br />
using System.Windows.Forms;<br />
using System.Data;<br />
using System.IO;<br />
<br />
namespace FlashTest<br />
{<br />
    /// <summary><br />
    /// Summary description for Form1.<br />
    /// </summary><br />
    public class Form1 : System.Windows.Forms.Form<br />
    {<br />
        private AxShockwaveFlashObjects.AxShockwaveFlash axShockwaveFlash1;<br />
        private System.Windows.Forms.Button button1;<br />
        private System.Windows.Forms.Button button2;<br />
        private System.Windows.Forms.Button button3;<br />
        private System.Windows.Forms.Button button4;<br />
        private System.Windows.Forms.TrackBar trackBar1;<br />
        private System.Windows.Forms.Label label1;<br />
        /// <summary><br />
        /// Required designer variable.<br />
        /// </summary><br />
        private System.ComponentModel.Container components = null;<br />
<br />
        public Form1()<br />
        {<br />
            //<br />
            // Required for Windows Form Designer support<br />
            //<br />
            InitializeComponent();<br />
<br />
            //<br />
            // TODO: Add any constructor code after InitializeComponent call<br />
            //<br />
        }<br />
<br />
        /// <summary><br />
        /// Clean up any resources being used.<br />
        /// </summary><br />
        protected override void Dispose( bool disposing )<br />
        {<br />
            if( disposing )<br />
            {<br />
                if (components != null) <br />
                {<br />
                    components.Dispose();<br />
                }<br />
            }<br />
            base.Dispose( disposing );<br />
        }<br />
<br />
        #region Windows Form Designer generated code<br />
        /// <summary><br />
        /// Required method for Designer support - do not modify<br />
        /// the contents of this method with the code editor.<br />
        /// </summary><br />
        private void InitializeComponent()<br />
        {<br />
            System.Resources.ResourceManager resources = new System.Resources.ResourceManager(typeof(Form1));<br />
            this.axShockwaveFlash1 = new AxShockwaveFlashObjects.AxShockwaveFlash();<br />
            this.button1 = new System.Windows.Forms.Button();<br />
            this.button2 = new System.Windows.Forms.Button();<br />
            this.button3 = new System.Windows.Forms.Button();<br />
            this.button4 = new System.Windows.Forms.Button();<br />
            this.trackBar1 = new System.Windows.Forms.TrackBar();<br />
            this.label1 = new System.Windows.Forms.Label();<br />
            ((System.ComponentModel.ISupportInitialize)(this.axShockwaveFlash1)).BeginInit();<br />
            ((System.ComponentModel.ISupportInitialize)(this.trackBar1)).BeginInit();<br />
            this.SuspendLayout();<br />
            // <br />
            // axShockwaveFlash1<br />
            // <br />
            this.axShockwaveFlash1.Anchor = ((System.Windows.Forms.AnchorStyles)((((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom) <br />
                | System.Windows.Forms.AnchorStyles.Left) <br />
                | System.Windows.Forms.AnchorStyles.Right)));<br />
            this.axShockwaveFlash1.Enabled = true;<br />
            this.axShockwaveFlash1.Location = new System.Drawing.Point(32, 24);<br />
            this.axShockwaveFlash1.Name = "axShockwaveFlash1";<br />
            this.axShockwaveFlash1.OcxState = ((System.Windows.Forms.AxHost.State)(resources.GetObject("axShockwaveFlash1.OcxState")));<br />
            this.axShockwaveFlash1.Size = new System.Drawing.Size(728, 504);<br />
            this.axShockwaveFlash1.TabIndex = 0;<br />
            this.axShockwaveFlash1.OnProgress += new AxShockwaveFlashObjects._IShockwaveFlashEvents_OnProgressEventHandler(this.axShockwaveFlash1_OnProgress);<br />
            // <br />
            // button1<br />
            // <br />
            this.button1.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Left)));<br />
            this.button1.Location = new System.Drawing.Point(32, 592);<br />
            this.button1.Name = "button1";<br />
            this.button1.Size = new System.Drawing.Size(80, 23);<br />
            this.button1.TabIndex = 1;<br />
            this.button1.Text = "Load";<br />
            this.button1.Click += new System.EventHandler(this.button1_Click);<br />
            // <br />
            // button2<br />
            // <br />
            this.button2.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Left)));<br />
            this.button2.Location = new System.Drawing.Point(128, 592);<br />
            this.button2.Name = "button2";<br />
            this.button2.Size = new System.Drawing.Size(80, 23);<br />
            this.button2.TabIndex = 2;<br />
            this.button2.Text = "Play";<br />
            this.button2.Click += new System.EventHandler(this.button2_Click);<br />
            // <br />
            // button3<br />
            // <br />
            this.button3.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Left)));<br />
            this.button3.Location = new System.Drawing.Point(224, 592);<br />
            this.button3.Name = "button3";<br />
            this.button3.Size = new System.Drawing.Size(80, 23);<br />
            this.button3.TabIndex = 3;<br />
            this.button3.Text = "Pause";<br />
            this.button3.Click += new System.EventHandler(this.button3_Click);<br />
            // <br />
            // button4<br />
            // <br />
            this.button4.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Left)));<br />
            this.button4.Location = new System.Drawing.Point(320, 592);<br />
            this.button4.Name = "button4";<br />
            this.button4.Size = new System.Drawing.Size(80, 23);<br />
            this.button4.TabIndex = 4;<br />
            this.button4.Text = "Stop";<br />
            this.button4.Click += new System.EventHandler(this.button4_Click);<br />
            // <br />
            // trackBar1<br />
            // <br />
            this.trackBar1.Location = new System.Drawing.Point(24, 536);<br />
            this.trackBar1.Maximum = 1;<br />
            this.trackBar1.Minimum = -1;<br />
            this.trackBar1.Name = "trackBar1";<br />
            this.trackBar1.Size = new System.Drawing.Size(744, 45);<br />
            this.trackBar1.TabIndex = 5;<br />
            this.trackBar1.TickStyle = System.Windows.Forms.TickStyle.None;<br />
            this.trackBar1.Value = -1;<br />
            this.trackBar1.ValueChanged += new System.EventHandler(this.trackBar1_ValueChanged);<br />
            // <br />
            // label1<br />
            // <br />
            this.label1.Location = new System.Drawing.Point(680, 600);<br />
            this.label1.Name = "label1";<br />
            this.label1.Size = new System.Drawing.Size(100, 16);<br />
            this.label1.TabIndex = 6;<br />
            // <br />
            // Form1<br />
            // <br />
            this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);<br />
            this.ClientSize = new System.Drawing.Size(792, 630);<br />
            this.Controls.Add(this.label1);<br />
            this.Controls.Add(this.trackBar1);<br />
            this.Controls.Add(this.button4);<br />
            this.Controls.Add(this.button3);<br />
            this.Controls.Add(this.button2);<br />
            this.Controls.Add(this.button1);<br />
            this.Controls.Add(this.axShockwaveFlash1);<br />
            this.Name = "Form1";<br />
            this.Text = "Form1";<br />
            ((System.ComponentModel.ISupportInitialize)(this.axShockwaveFlash1)).EndInit();<br />
            ((System.ComponentModel.ISupportInitialize)(this.trackBar1)).EndInit();<br />
            this.ResumeLayout(false);<br />
<br />
        }<br />
        #endregion<br />
<br />
        /// <summary><br />
        /// The main entry point for the application.<br />
        /// </summary><br />
        [STAThread]<br />
        static void Main() <br />
        {<br />
            Application.Run(new Form1());<br />
        }<br />
<br />
        private void button1_Click(object sender, System.EventArgs e)<br />
        {<br />
            axShockwaveFlash1.Movie = Directory.GetCurrentDirectory() + "\\A02_09.swf";<br />
            axShockwaveFlash1.StopPlay();<br />
            trackBar1.Maximum = axShockwaveFlash1.TotalFrames;<br />
            label1.Text = axShockwaveFlash1.TotalFrames.ToString();<br />
        }<br />
<br />
        private void button2_Click(object sender, System.EventArgs e)<br />
        {<br />
            axShockwaveFlash1.Play();<br />
        }<br />
<br />
        private void button3_Click(object sender, System.EventArgs e)<br />
        {<br />
            axShockwaveFlash1.StopPlay();<br />
        }<br />
<br />
        private void button4_Click(object sender, System.EventArgs e)<br />
        {<br />
            axShockwaveFlash1.StopPlay();<br />
            axShockwaveFlash1.FrameNum = -1;<br />
        }<br />
<br />
// why this is not working... ?<br />
        private void axShockwaveFlash1_OnProgress(object sender, AxShockwaveFlashObjects._IShockwaveFlashEvents_OnProgressEvent e)<br />
        {<br />
            this.trackBar1.Value = axShockwaveFlash1.FrameNum;<br />
        }<br />
<br />
        private void trackBar1_ValueChanged(object sender, System.EventArgs e)<br />
        {<br />
            axShockwaveFlash1.FrameNum = trackBar1.Value;<br />
        }<br />
    }<br />
}<br />
<br />

Thanks All..

modified on Tuesday, November 24, 2009 1:22 AM

Re: i have problem axShockwaveFlash1_OnProgress

Richard MacCutchan23-Nov-09 21:52

Richard MacCutchan

23-Nov-09 21:52

bekzod009 wrote:
Thanks

And what is your problem?

Linq question, error I do not understand

Calvin Bell23-Nov-09 12:49

Calvin Bell

23-Nov-09 12:49

I inherited a project at my job, and there is a line of code that is giving me an error. I am having trouble figuring it out.

In the method below, data is being pulled from a table, and put into a CustomerData object. The "Expiration" line, which is a DateTime, is the one that is erroring. If I take out this part: "() => new License()" in the .FirstOrDefault method, it compiles, but when I click on the part that populates the grid I get "Object reference not set to an instance of an object.". If I try to compile with this part: "() =&gt; new License()" it gives me this error: "The type arguments for method 'System.Linq.Enumerable.FirstOrDefault<TSource>(System.Collections.Generic.IEnumerable<TSource>, System.Func<TSource,bool>)' cannot be inferred from the usage. Try specifying the type arguments explicitly."
If I assign "Expiration" to a static DateTime, then it works fine and populates the return with all the same date/time.

So, I think the linq part of the statement is wrong and I am getting null back (when the field is not nullable), or I need to specify the type somewhere in there.

Any help would be appreciated!

internal static IEnumerable<CustomerData> GetCustomers(this HttpRequest request)
{
var dc = new RootDataContext();

return dc.Customers.ToList().Select(c => new CustomerData()
{
CustomerId = c.CustomerID,
StoreNumber = c.StoreNumber,
StoreName = c.StoreName,
OwnerName = c.OwnerName,
City = c.City,
State = c.State,
TimeZone = c.TimeZone,
//Compile time error, "specify type"
//Expiration = c.Licenses.Where(l => l.ProductID > 1002).OrderBy(l => l.Expiration).FirstOrDefault(() => new License()).Expiration,
//Compiles, errors "null reference"
//Expiration = c.Licenses.Where(l => l.ProductID > 1002).OrderBy(l => l.Expiration).FirstOrDefault().Expiration,
//works, all the same datetime
//Expiration = new DateTime(2010, 12, 10),
Trial = c.Licenses.Where(l => l.ProductID > 1002).Any(l => l.Trial),
InventoryDate = c.Products_Database_Eagle != null ? c.Products_Database_Eagle.InventoryDate : default(DateTime),
Upload = c.Products_Database_Eagle != null ? c.Products_Database_Eagle.Upload : false,
Finalize = c.Products_Database_Eagle != null ? c.Products_Database_Eagle.Finalize : false,
Registration = c.RegistrationKey,
});
}

Re: Linq question, error I do not understand

Ravi Bhavnani23-Nov-09 13:49

Ravi Bhavnani

23-Nov-09 13:49

Looks like the search failure is returning a null license (since you specified FirstOrDefault) whose DateTime member you're trying to access.

/ravi

My new year resolution: 2048 x 1536
Home | Articles | My .NET bits | Freeware
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Re: Linq question, error I do not understand

Calvin Bell24-Nov-09 2:49

Calvin Bell

24-Nov-09 2:49

So what would I do there?

I cant leave it blank, or else it gives me a object reference exception.

The code that was in there "() => new License()" has a compile time error that says "The type arguments for method 'System.Linq.Enumerable.FirstOrDefault<TSource>(System.Collections.Generic.IEnumerable<TSource>, System.Func<TSource,bool>)' cannot be inferred from the usage. Try specifying the type arguments explicitly."

I guess I need to know how to specify the type explicitly. I think it is trying to create a new License if it cannot find one in the select statement, which is why it leaves it blank if it cannot find one.

Re: Linq question, error I do not understand

Ravi Bhavnani24-Nov-09 3:52

Ravi Bhavnani

24-Nov-09 3:52

Calvin Bell wrote:
So what would I do there?

You need to evaluate your design and decide how the code should work, rather than simply tweaking the code to compile and run under circumstances. What DateTime do you want to do if the license is not found? A null reference, DateTime.MinValue, something else? The choice is yours.

/ravi

My new year resolution: 2048 x 1536
Home | Articles | My .NET bits | Freeware
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can TcpClient :: GetStream() be used in separate threads for the same TcpClient ?

abiemann23-Nov-09 12:44

abiemann

23-Nov-09 12:44

my server implements a reading thread that blocks until data is received.

what I'd like to do is have a designated thread that only writes as data becomes available (an event would be created that contains the TcpClient in the event argument).

Therefore the question: is it possible to use TcpClient.GetStream() twice for the same TcpClient ?

Re: can TcpClient :: GetStream() be used in separate threads for the same TcpClient ?

April Fans24-Nov-09 0:32

April Fans

24-Nov-09 0:32

It's not possible.

'tcpclient.getstream() ' can get all btye[] by server socket sending.

April

Comm100 - Leading Live Chat Software Provider

modified 27-May-14 21:53pm.

Re: can TcpClient :: GetStream() be used in separate threads for the same TcpClient ?

Paulo Zemek24-Nov-09 1:15

Paulo Zemek

24-Nov-09 1:15

Yes, it's possible.
You can't read or write by two threads, but having a thread that only reads and a thread that only writes is perfectly possible. I always do this but, in fact, I call GetStream only once, and pass the returned stream as the parameter to the threads, but I really think this don't change anything.

Also, be carefull not to close the stream before you finished, as closing the stream will also close the tcp/ip connection.

Re: can TcpClient :: GetStream() be used in separate threads for the same TcpClient ?

abiemann30-Nov-09 6:41

abiemann

30-Nov-09 6:41

passing the TcpClient object around and calling GetStream() once in the read thread and once in the write thread worked just fine.

Since I found this out I have updated my code to use a secure socket and now I'm passing around a NegotiateStream object (but no need to call GetStream) Smile | :)

Webbrowser control print preview not working for background color

Shukra23-Nov-09 12:04

Shukra

23-Nov-09 12:04

Hi,

In c# i generated HTML report (colored).
I am using Webbrowser control.
I need to print it. But unfortunately i cannot print the color (background color). why?
A sample report is as below.

<html>
<head>
<title>Test</title>

</head>

<body align=center >

<table align=center border=0 width=1000>

<tr>

	<td align=center class=title style='border:2px solid red;'>110P-1 PRODUCTION SCHEDULE</td>

</tr>

</table>

 

<table align=center border=1 width=1000 cellspacing=0 cellpadding=0>

<tr>

	<td colspan=3 align=right>&nbsp; <b>TOTALS:</b> </td>

	<td align=center ><b>22160.00</b></td>

	<td align=center ><b>15828.57</b></td>

	<td align=center ><b>18000.09</b></td>

	<td align=center><b>2971.36</b></td>

	<td align=center><b>33</b></td>

	<td >&nbsp;</td>

</tr>

<tr>

	<td align=center ><b>DEL.DATE</b></td>

	<td align=center ><b>COLOUR</b></td>

	<td align=center><b>ADDRESS</b></td>

	<td align=center ><b>L/M</b></td>

	<td align=center ><b>HOURS@1.4m</b></td>

	<td align=center ><b>COMPLETE</b></td>

	<td align=center ><b>REMAIN HOURS</b></td>

	<td align=center ><b>PACKS</b></td>

	<td align=center ><b>STATUS</b></td>

</td>

<tr><td align=center >&nbsp;20/11/2009</td>
<td align=center style='background-color:#FF8C00;'>&nbsp;</td>
<td align=center >&nbsp;Hamilton Iland</td>
<td align=center >&nbsp;20310.00</td>
<td align=center >&nbsp;14507.14</td>
<td align=center>&nbsp;18000.09</td>
<td align=center >&nbsp;1649.94</td>
<td align=center >&nbsp;33</td>
<td align=center >&nbsp;</td></tr>



<tr><td align=center >&nbsp;16/11/2009</td>
<td align=center style='background-color:#14A0E6;'>&nbsp;</td>
<td align=center >&nbsp;Bankstown</td>
<td align=center >&nbsp;1250.00</td>
<td align=center >&nbsp;892.86</td>
<td align=center >&nbsp;0.00</td>
<td align=center >&nbsp;892.86</td>
<td align=center >&nbsp;</td>
<td align=center >&nbsp;</td></tr>
</tr>
</table>

</body>

---------------------------------- ---------------------
I am using .NET framework 3.5
I have color printer. and if i changed table border to red, blue, etc for border, it prints in color.
It only does not work with table cell (TD) background color.

Thanks in advance
Shukra

Re: Webbrowser control print preview not working for background color

Dave Kreskowiak23-Nov-09 12:52

Dave Kreskowiak

23-Nov-09 12:52

Because it follows the settings for Internet Explorer, which, by default, doesn't print the background at all.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007, 2008
But no longer in 2009...

Re: Webbrowser control print preview not working for background color

Ravi Bhavnani23-Nov-09 13:55

Ravi Bhavnani

23-Nov-09 13:55

To follow up on Dave's response, you don't need to use a WebBrowserControl to print your document. Simply save the HTML to a temporary file and do the .NET equivalent of ShellExecute (..., "print", ...) to print it. The .NET equivalent is Process.Start().

/ravi

My new year resolution: 2048 x 1536
Home | Articles | My .NET bits | Freeware
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Re: Webbrowser control print preview not working for background color

Shukra23-Nov-09 17:23

Shukra

23-Nov-09 17:23

Thanks Ravi,
Will you pls tell me if.
Is there any way to change IE printer settings from c# code?
1.I want to dynamically set page orientation to "Landscape" or "Portrait"
2.I want to remove the header or footer. (I can change the values from registry, but don't know how to disable it?)

Thanks again,
Shukra

Re: Webbrowser control print preview not working for background color

Ravi Bhavnani23-Nov-09 17:47

Ravi Bhavnani

23-Nov-09 17:47

Clickety[^]

/ravi

My new year resolution: 2048 x 1536
Home | Articles | My .NET bits | Freeware
ravib(at)ravib(dot)com

Emgu CV Vs AForge.NET Vs OpenCVDotNet

Lynndah21223-Nov-09 8:55

Lynndah212

23-Nov-09 8:55

Hi,

I am currently doing some research to see which of these wrappers of OpenCV to use for myfinal year project. I am looking to develop something in C# to recognise the movement of a hand.

Any advice is appreciated.

Cheers!

Re: Emgu CV Vs AForge.NET Vs OpenCVDotNet

Dave Kreskowiak23-Nov-09 10:18

Dave Kreskowiak

23-Nov-09 10:18

Great! Was there a question in there, or did you just want to announce to the world what you're doing?

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007, 2008
But no longer in 2009...

Re: Emgu CV Vs AForge.NET Vs OpenCVDotNet

Lynndah21223-Nov-09 11:14

Lynndah212

23-Nov-09 11:14

My Bad! Engrossed in this thing I cant think straight! Confused | :confused:

I want to find out which one is better. Thanks in advance for your suggestions!

Re: Emgu CV Vs AForge.NET Vs OpenCVDotNet

Dave Kreskowiak23-Nov-09 12:51

Dave Kreskowiak

23-Nov-09 12:51

The one that meets all of your specifications.

"Better" is a subjective term. The only way you're going to know is to test each one against what you want to do.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007, 2008
But no longer in 2009...

Read and Write a file at the same time?

Tony496623-Nov-09 4:41

Tony4966

23-Nov-09 4:41

Hi

Is there a way of writing and reading a csv file from C# at the same time?

I mean I have two separated projects; one keeps writing data into a csv file and the other one is to read the data from the same csv that is also being written.

When I tried this, it always says the file can't be accessed because it's being used by another process.

Is there anyway of getting around this?

Many thanks indeed.

Re: Read and Write a file at the same time?

Eddy Vluggen23-Nov-09 4:44

Eddy Vluggen

23-Nov-09 4:44

Tony4966 wrote:
Is there anyway of getting around this?

The easiest way that comes to mind is to replace the file with a desktop database. You can read/write into the database from multiple points, and export the parts to CSV if you need them.

I are Troll Suspicious | :suss:

Re: Read and Write a file at the same time?

PIEBALDconsult23-Nov-09 5:02

PIEBALDconsult

23-Nov-09 5:02

The program that writes the file needs to allow other processes to read it; this is done when the stream is opened.

But, really, this is unlikely to be a good design. Do you really want the file? Or are you only trying to have inter-process communication? If you don't actually need the file; then find a better way.

Re: Read and Write a file at the same time?

Tony496623-Nov-09 5:24

Tony4966

23-Nov-09 5:24

You are right. This is probably not a good design but I just want to get this working as quickly as possible and it is just a short term solution.

So please can you be a little bit more specific about how exactly I let the program that writes into the file allow other programs to read the file at the same time?

A quick example of would be

string path = @"C:\Documents and Settings\";
            
            string filename = "tester.csv";

            TextWriter writer = new StreamWriter(path + filename, false);
            
            for (int j = 0; j < 10; j++)
                writer.WriteLine("{0}, {1}", j,2 * j);

Many thanks indeed.

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.