How to retrieve image with Html - C# Discussion Boards

Re: if/else statement for command button; object reference not set to an instance error

Paul Conrad6-Jul-06 8:00

Paul Conrad

6-Jul-06 8:00

leckey wrote:
must have had something commented

Oops, that happens Big Grin | :-D

Re: if/else statement for command button; object reference not set to an instance error

Paul Conrad6-Jul-06 8:04

Paul Conrad

6-Jul-06 8:04

leckey wrote:
Still getting the null error.

Is it because of ds? I do not see it being declared or initialized anywheres. You may want to hand optimize the if block and else block by pulling all of the common code out in front of the if statement, if at all possible Smile | :)

Re: if/else statement for command button; object reference not set to an instance error

Guffa6-Jul-06 8:16

Guffa

6-Jul-06 8:16

Look at this code:

DataTable dt = ds.Tables["Rest"]; ds = (DataSet) Session["ds"];

You are using ds before you assign a value to it.

---
b { font-weight: normal; }

Re: if/else statement for command button; object reference not set to an instance error

leckey6-Jul-06 8:40

leckey

6-Jul-06 8:40

D'oh! Okay, I get it to add a second line. (Small steps...small steps.)

New problem (imagine that!) When it adds the second line, it resets the first line. So anything I had previously entered is blanked out. How do I get it to retain what I already entered? I thought setting the dataset to the session did this.

Current code:

private void Button2_Click(object sender, System.EventArgs e)<br />
		{	<br />
<br />
			DataGridItemCollection items = dgParts.Items;<br />
			<br />
		<br />
			int rows = items.Count;<br />
			if (rows == 0)<br />
			{<br />
		<br />
				BindData();<br />
				DataTable dt = ds.Tables["Rest"];<br />
				DataRow row;<br />
				row = dt.NewRow();<br />
				strPartNumberInputReference = txtSearchPart.Text;<br />
				row["PartNumber"] = strPartNumberInputReference; <br />
				row["DrawingNumber"]=DBNull.Value;<br />
				row["DrawingRevision"]=DBNull.Value;<br />
				row["DwgPath"]=DBNull.Value;<br />
<br />
				dt.Rows.Add(row);			<br />
				dt.AcceptChanges();	<br />
			<br />
				dgParts.DataSource=dt;			<br />
				dgParts.DataBind();<br />
				Session["test"]=ds;<br />
			}<br />
<br />
			else<br />
			{<br />
				ds = (DataSet)Session["test"];<br />
				DataTable dt = ds.Tables[0];<br />
				DataRow row;<br />
				row = dt.NewRow();	<br />
				strPartNumberInputReference = txtSearchPart.Text;<br />
				row["PartNumber"] = strPartNumberInputReference; <br />
				row["DrawingNumber"]=DBNull.Value;<br />
				row["DrawingRevision"]=DBNull.Value;<br />
				row["DwgPath"]=DBNull.Value;<br />
				dt.Rows.Add(row);			<br />
				dt.AcceptChanges();			  <br />
				dgParts.DataSource=dt;			<br />
				dgParts.DataBind();<br />
			}<br />
<br />
		}

Thanks again for your help!

Re: if/else statement for command button; object reference not set to an instance error

Paul Conrad6-Jul-06 6:59

Paul Conrad

6-Jul-06 6:59

It could be that you're missing

DataTable dt = ds.Tables["Rest"];

in the block following the else statement.

ListView Item/Subitem backcolor solution

Aaron Dilliard6-Jul-06 5:33

Aaron Dilliard

6-Jul-06 5:33

A few days ago I posted a message wondering if anyone had any info on a problem with the ListView in .NET 2.0. The backcolor would disappear when scrolling or selecting and wouldnt come back until the form lost focus and got it back. (As a side note, calling Invalidate() or Refresh() on the ListView caused ALL items to lose color.) The solution turns out to be simple. In the Main method, just add Application.EnableVisualStyles(). HTH anyone with the same issue.

Aaron

Plugin can't see referenced code

berry seltzer6-Jul-06 5:17

berry seltzer

6-Jul-06 5:17

I'm developing a plugin architecture for an application that will translate some database schema to an XML document that complies with an XML schema. Most of my architecture has been modelled after the article posted by 'Redth' here: http://www.codeproject.com/csharp/pluginsincsharp.asp

I'm able to call some methods from the host so long as those methods do not reference any classes outside of the namespace that the host sits in. Once I attempt to call methods from a namespace that it outside of the host (ie the namespace that contains all the data binding for the XML schema that I need to use) I get a MissingMethodException. All the correct references are in place and everything builds fine, yet the plugin can't access any of the classes in the data binding layer at runtime.

Any suggestions? Thanks!

How to retrieve image with Html

Bluebamboo6-Jul-06 5:13

Bluebamboo

6-Jul-06 5:13

Hi all,
I am planning to make a simple proxy server and i have been trying to retrieve the contents of a web page via Socket and send the display (NetworkStream.Flush) to a client browser. the html contents are being displayed properly but the images are not there. even the httpWebResponse.ContentLength shows the length of html content only.

someone plz tell me how to retrieve the images along with html using HttpWebRequest so that the page displays properly.

Thanks in advance.

Re: How to retrieve image with Html

Not Active6-Jul-06 5:32

Not Active

6-Jul-06 5:32

If read through these forums you will see that re-asking the same question, even if it is re-phrased, doesn't help.

Re: How to retrieve image with Html

Bluebamboo6-Jul-06 5:46

Bluebamboo

6-Jul-06 5:46

hi Mark,

actually, i has searched lots of forums, but i got nothing, i believe it is a quite common question, but i really canot find its answer.

if you know any relevant URL resources, plz tell me.

many thanks

Re: How to retrieve image with Html

led mike6-Jul-06 5:42

led mike

6-Jul-06 5:42

Bluebamboo wrote:
retrieve the images along with html

Mark is correct, besides HTTP does not work that way. Perhaps you should do some studying on the subject prior to attempting development? Sigh | :sigh:

"Just about every question you've asked over the last 3-4 days has been "urgent". Perhaps a little planning would be helpful?"
Colin Angus Mackay in the C# forum

led mike

Re: How to retrieve image with Html

Bluebamboo6-Jul-06 5:58

Bluebamboo

6-Jul-06 5:58

sorry about the re-ask. but i really need help, and i am fastened on this problem long time~~

A question is really confusing me , how does a proxy program work that way when it responses the content of webpage with images to client explorer Confused | :confused:

Re: How to retrieve image with Html

led mike6-Jul-06 6:26

led mike

6-Jul-06 6:26

I am not trying to be rude but HTTP is a fairly large protocol and using a forum is not the way to learn it. Go and study the HTTP protocol so that you "know" what you need to develop before you start writing code.

try Google: HTTP protocol tutorial

good luck Smile | :)

"Just about every question you've asked over the last 3-4 days has been "urgent". Perhaps a little planning would be helpful?"
Colin Angus Mackay in the C# forum

led mike

Re: How to retrieve image with Html

Bluebamboo6-Jul-06 6:31

Bluebamboo

6-Jul-06 6:31

good suggetion for me
thank a lot Smile | :)

tiff file reading

roopeshgangwar6-Jul-06 4:16

roopeshgangwar

6-Jul-06 4:16

how to read tiff file content.

Roopesh Singh Gangwar

Re: tiff file reading

rubben6-Jul-06 5:17

rubben

6-Jul-06 5:17

Have you tried FreeImage? It comes with a nice C# wrapper and seems to handle every TIFF type I've tried except JPEG 6.0 compression. If you need low-level stuff, you could write a wrapper for libtiff.

Re: tiff file reading

roopeshgangwar6-Jul-06 9:19

roopeshgangwar

6-Jul-06 9:19

No i have not tried FreeImage. If you have code for that can u share it with me.

Roopesh Singh Gangwar

Treeview [modified]

travellermania6-Jul-06 3:49

travellermania

6-Jul-06 3:49

I guess this is pretty stupid question but ...
If I know the Tag (full path of the node), how can I use it in order of Checking the node.

Thanks

-- modified at 9:49 Thursday 6th July, 2006

Re: Treeview

Nader Elshehabi6-Jul-06 5:18

Nader Elshehabi

6-Jul-06 5:18

Hello
Try to parse your tag & select them node by node, until you reach your target node.
Slow, but sure
Don't forget to put in mind that the tag may be in incorrect format

eg. -NOT A REAL CODE-

try
{
string MyTag = TheTag
Get firstNode Name
Select it from the root
remove its name from MyTag
while(MyTag.Length > 0)
{
Get NextNode Name
Select NextNode from the SelectedNode.Nodes
Remove its name from MyTag
}
}
catch
{
//error
}
//Now We got our node

Regards Rose | [Rose]

array exporting in c++ dll to c# client

Tugberk_Kara6-Jul-06 3:21

Tugberk_Kara

6-Jul-06 3:21

I have a function in c++ returning array as:

int * funcArg(int *a ) {
int * DLLArg;
DLLArg=a;

return DLLArg;
};

I exported this function in dll( I checked with dumpbin.exe)

I declared this function in c# client as:

[DllImport("DenemeNonMfcDll.dll")]
public extern static int [] funcArg(int [] a);

And I called this function in c# client as:

int [] intArray;

intArray = new int[3] {0, 1, 2};

foreach (int num in funcArg(intArray))
{
System.Console.WriteLine(num.ToString());
}

But I got System.Runtime.InteropServices.MarshalDirectiveException and it says it can not marshal return value.

What should I do?
URGENT HELP!!!

Re: array exporting in c++ dll to c# client

rubben6-Jul-06 5:06

rubben

6-Jul-06 5:06

Try changing the declaration to:
public extern static IntPtr funcArg(int[] a);
and use Marshal.Copy to copy the returned pointer into an array.

Re: array exporting in c++ dll to c# client

Tugberk_Kara6-Jul-06 5:36

Tugberk_Kara

6-Jul-06 5:36

I could not resolve the issue. still does not work!!!

class Class1
{
[DllImport("DenemeNonMfcDll.dll",EntryPoint="?Sub@DLLclass@@QAEHHH@Z")]
public extern static int Sub(int a, int b);

[DllImport("DenemeNonMfcDll.dll")]
[return: MarshalAs(UnmanagedType.SafeArray)]
public extern static IntPtr funcArg(int [] a);

public static int [] intArray = new int [3] {0,1,2};

static void Main(string[] args)
{
int [] array2={};

IntPtr ipr= funcArg(intArray);

Marshal.Copy(ipr,array2,0,3);

foreach (int num in array2 )
{
System.Console.WriteLine(num.ToString());
}

//Console.WriteLine("sonuc"+);
Console.WriteLine("Press any key to continue...");
Console.ReadLine();
}
}

Displaying a label over other controls

anderde6-Jul-06 3:20

anderde

6-Jul-06 3:20

I have been looking for several hours now trying to figure out how to display a transparent back-color label over other controls. I have a user-control with tons of controls in it such as text-boxes, combo-boxes, etc. I want to display a BIG RED LABEL titled "VOID" over this user-control sometimes when the control is displayed. But I want the user to still be able to read the data in the controls behind the label.

When I set the back-color property of the label to transparent, it doesn't seem to work. I have also tried creating a custom label and over-riding the CreateParams property.

I have also now tried making a graphics and using the drawstring method. However, I once again cannot figure out a way to make the graphic the top most control over the other controls. I even changed the other controls z-order.

PLEASE HELP AS I AM BECOMING DESPERATE!!

Re: Displaying a label over other controls

Not Active6-Jul-06 3:30

Not Active

6-Jul-06 3:30

I believe the only way you're are going to accomplish this would be to override the control's OnPaint method and draw your text.

Re: Displaying a label over other controls

anderde6-Jul-06 3:44

anderde

6-Jul-06 3:44

By drawing it in the OnPaint method, I still have not figured out how to make the Graphics object the top most control.

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