Using MemoryStream instead of FileStream problem - C# Discussion Boards

m_mond11-Mar-03 9:59

11-Mar-03 9:59

Is there a way to set the mime type on the IHTMLDocument2 object? I could have a ton of XML messages to display according to user selection -- having to save these as temp files or use one file as a temp writing space could be a pain. I could save some trouble if the mime type could be changed...is is possible?

Re: Viewing XML in AxSHDocVW

Stephane Rodriguez.11-Mar-03 10:22

Stephane Rodriguez.

11-Mar-03 10:22

I am aware of only two ways to associate a mime type to a document, in order to render the document in Internet Explorer :
- have a URI (local file, remote file) to play with, use Internet Explorer API to navigate to this URI
- have a web server generate the appropriate mimetype for you. In your case, the web server would simply redirect the stream, only adding the appropriate http header to it.

I am not aware of a successful way of changing the mimetype on-the-fly playing with the HTML Meta tag, of the form :
<META HTTP-EQUIV="Content-Type" CONTENT="text/html">

Re: Viewing XML in AxSHDocVW

m_mond11-Mar-03 10:42

m_mond

11-Mar-03 10:42

Yeah, playing around I see that the Type property is read-only. PutProperty on the AxWebBrowser doesn't seem to work either, but I can't find any docs on the valid data elements that can be passed to this method. Gotta love it when cool components like this go undocumented!

I think I'll just resort to your first suggestion : stream to a file then load that file in Navigate.

Re: Viewing XML in AxSHDocVW

leppie11-Mar-03 10:53

leppie

11-Mar-03 10:53

There some VB.NET (ouch) code (XMLViewer) on GotDotNet just posted last week doing what you want to do, it seems alot easier to work with VB.NET with these HTML interfaces.

I rated this article 2 by mistake. It deserves more. I wanted to get to the second page... - vjedlicka 3:33 25 Nov '02

Re: Viewing XML in AxSHDocVW

Stephane Rodriguez.11-Mar-03 11:20

Stephane Rodriguez.

11-Mar-03 11:20

clickety[^]

He loads the Xml content from a file, transforms it using a default xslt, and then writes the output html in the web browser.

The sample itself is of no help, unless m_mond writes local files.

The good news is that the .NET System.Xml namespace both can load a xml file or a stream. This provides the required tool.

Draw image with alpha blending ?

Wizard_0111-Mar-03 8:54

Wizard_01

11-Mar-03 8:54

Draw image with alpha blending ? help, please

Getting AVI's into a C# Windows Form project

antoine@orchus-tech11-Mar-03 7:38

antoine@orchus-tech

11-Mar-03 7:38

Hello,

I am writing a Windows Form program in C#.
It play some AVI's and I want to embed these
AVI's into a resource or something to deny
the user from accesing them.

How do I do that ?

thanks!

Orlanda

Using MemoryStream instead of FileStream problem

LongRange.Shooter11-Mar-03 7:23

LongRange.Shooter

11-Mar-03 7:23

We have written a managed zip file component which we are deploying in a code elevate tool. We can create a file stream, write the zip file to disk, and it is ready to send to the receiving server. However, once the move is complete all we do is delete the file. It seems that it would be more valuable to just keep it all in memory and send the memory object to the receiving server.

The first go-around our file stream works great, fast, and gives us a zip file we can open.

Moving the stream to a MemoryStream, we get a larger file than what we had with our first test, and it is an invalid zip file which makes it real hard to determine what is going wrong.

Has anyone done a movement from file to memory with success and what can you suggest for a guidline to make this work.

_____________________________________________
_{The world is a dangerous place.
Not because of those that do evil,
but because of those who look on and do nothing.}

Re: Using MemoryStream instead of FileStream problem

leppie11-Mar-03 7:38

leppie

11-Mar-03 7:38

This is what have used with success:

<font  size=2 face="Courier New"><font color="#FFFFFF">         </font><font color="#008040">// the following replaces Assembly.LoadFrom()
   </font><font color="#000000">FileStream stream </font>= <font color="#000000">File</font>.<font color="#000000">OpenRead</font>(<font color="#000000">filename</font>);
   <font color="#000000">byte</font>[] <font color="#000000">buffer </font>= <font color="#0000FF">new </font><font color="#000000">byte</font>[<font color="#000000">stream</font>.<font color="#000000">Length</font>];
   <font color="#000000">stream</font>.<font color="#000000">Read</font>(<font color="#000000">buffer</font>, <font color="#FF0000">0</font>, (<font color="#0000FF">int</font>)<font color="#000000">stream</font>.<font color="#000000">Length</font>);
   <font color="#000000">stream</font>.<font color="#000000">Close</font>();
<font color="#0000FF">#if(DEBUG)
   </font><font color="#008040">//this wont show in VS.NET, but symbols IS in fact loaded
   </font><font color="#000000">stream </font>= <font color="#000000">File</font>.<font color="#000000">OpenRead</font>(<font color="#000000">filename</font>.<font color="#000000">Replace</font>(<font color="#FF8000">".dll"</font>, <font color="#FF8000">".pdb"</font>));
   <font color="#000000">byte</font>[] <font color="#000000">debugbuffer </font>= <font color="#0000FF">new </font><font color="#000000">byte</font>[<font color="#000000">stream</font>.<font color="#000000">Length</font>];
   <font color="#000000">stream</font>.<font color="#000000">Read</font>(<font color="#000000">debugbuffer</font>, <font color="#FF0000">0</font>, (<font color="#0000FF">int</font>)<font color="#000000">stream</font>.<font color="#000000">Length</font>);
   <font color="#000000">stream</font>.<font color="#000000">Close</font>();

   <font color="#000000">Type</font>[] <font color="#000000">types </font>= <font color="#000000">Assembly</font>.<font color="#000000">Load</font>(<font color="#000000">buffer</font>, <font color="#000000">debugbuffer</font>).<font color="#000000">GetExportedTypes</font>();
<font color="#0000FF">#else
   </font><font color="#000000">Type</font>[] <font color="#000000">types </font>= <font color="#000000">Assembly</font>.<font color="#000000">Load</font>(<font color="#000000">buffer</font>).<font color="#000000">GetExportedTypes</font>();
<font color="#0000FF">#endif
</font></font>

I rated this article 2 by mistake. It deserves more. I wanted to get to the second page... - vjedlicka 3:33 25 Nov '02

Re: Using MemoryStream instead of FileStream problem

LongRange.Shooter11-Mar-03 9:07

LongRange.Shooter

11-Mar-03 9:07

lippie -- looks like you may have got things reversed. We have working file steam logic we just cannot get the memory stream to work.

Here is what works:

<br />
public static int ZipFilesInto(string zipFileName,string dirPath,string searchPattern,bool recursive, DateTime dateFilter, string basePath)<br />
{<br />
    ZipFile zf=new ZipFile(zipFileName,ZipFileOpenMode.Write);<br />
    zf.BasePath=basePath;<br />
    int ret=zf.Add(dirPath, searchPattern, recursive, dateFilter);<br />
    zf.CloseZipFile();<br />
    return ret;<br />
}<br />

We are trying to replace this with a memory stream. Here is what does not work.

<br />
public static byte[] ZipFilesToMemory(string dirPath,string searchPattern,bool recursive, DateTime dateFilter, string basePath)<br />
{<br />
    MemoryStream m=new MemoryStream();<br />
    ZipFile zf=new ZipFile(m,ZipFileOpenMode.Write);<br />
    zf.BasePath=basePath;<br />
    int ret=zf.Add(dirPath, searchPattern, recursive, dateFilter);<br />
    byte[] buf = new byte[m.Length];<br />
    int ost=0;<br />
    int cnt=0;<br />
    while(true)<br />
    {<br />
	cnt=m.Read(buf,ost,4096);<br />
	if(cnt==0)break;<br />
	ost+=cnt;<br />
    }<br />
    zf.CloseZipFile();<br />
    return buf;<br />
}<br />

And....here are the methods being called:

<br />
		public ZipFile(string zipFilePath,ZipFileOpenMode zom)<br />
		{<br />
			ZipFilePath=zipFilePath;<br />
			OpenZipFile(zom);<br />
		}<br />
		public ZipFile(Stream baseStream,ZipFileOpenMode zom)<br />
		{<br />
			if(zom==ZipFileOpenMode.Write)<br />
			{<br />
				zos = new ZipOutputStream(baseStream);<br />
			}<br />
			else<br />
			{<br />
				zis = new ZipInputStream(baseStream);<br />
			}<br />
		}<br />
		public enum ZipFileOpenMode<br />
		{<br />
			/// <summary><br />
			///	Open the zip for read only to extract or inspect the contents<br />
			/// </summary><br />
			Read,<br />
			/// <summary><br />
			/// Open the file as an output for a new zip file or to add to an existing zip file<br />
			/// </summary><br />
			Write<br />
		}<br />
		public bool OpenZipFile(ZipFileOpenMode zfom)<br />
		{<br />
			if(zfom == ZipFileOpenMode.Read)<br />
				zis = new ZipInputStream(File.OpenRead(ZipFilePath));<br />
			else<br />
				zos = new ZipOutputStream(File.Create(ZipFilePath));<br />
<br />
			return true;<br />
		}<br />
		public bool CloseZipFile()<br />
		{<br />
			if(zis!=null)zis.Close();<br />
			if(zos!=null)zos.Close();<br />
			zis=null;<br />
			zos=null;<br />
			return true;<br />
		}<br />

It appears the developer is treating both the file stream writer and the memory stream writer as equals, which should be correct. In debug, the data in the memory stream is less than the total capacity allocated yet when he persists it to disk it saves the total capacity size.

_____________________________________________
_{The world is a dangerous place.
Not because of those that do evil,
but because of those who look on and do nothing.}

Re: Using MemoryStream instead of FileStream problem

leppie11-Mar-03 10:27

leppie

11-Mar-03 10:27

It seems the Zip library's Stream implementtaion is incorrect. What library are you using? I had problems with the one provided at SharpDevelop's site a few months back, and AFAI can remmeber, it was to do with streams.

I rated this article 2 by mistake. It deserves more. I wanted to get to the second page... - vjedlicka 3:33 25 Nov '02

Re: Using MemoryStream instead of FileStream problem

LongRange.Shooter12-Mar-03 7:13

LongRange.Shooter

12-Mar-03 7:13

Ahhhh -- we found the issue. The trouble is that the MemoryStream is not like most streams in that it does not have a reader and a writer. This makes it a bi-directional stream. Eek! | :eek:

As such it does not rewind itself for a read after a write. You must specify the position in the stream you want to read from or write to. So we created a read method and a write method to get it to work. Thus the final product is:

<br />
		public static byte[] ZipFilesToMemory(string dirPath,string searchPattern,<br />
  bool recursive, DateTime 				dateFilter, string basePath)<br />
		{<br />
			MemoryStream m=new MemoryStream();<br />
			ZipFile zf=new ZipFile(m,ZipFileOpenMode.Write);<br />
			zf.BasePath=basePath;<br />
			int ret=zf.Add(dirPath, searchPattern, recursive, dateFilter);<br />
			zf.ZipOutputStream.Finish();<br />
			byte[] buf = new byte[m.Length];<br />
			m.Position=0;<br />
			m.Read(buf,0,(int)m.Length);<br />
			zf.CloseZipFile();<br />
			return buf;<br />
		}<br />
<br />
		public static int ExtractFromMemory(byte[] zipBuffer,string targetPath)<br />
		{<br />
			MemoryStream m=new MemoryStream();<br />
			m.Write(zipBuffer,0,zipBuffer.Length);<br />
			ZipFile zf=new ZipFile(m,ZipFileOpenMode.Read);<br />
			int cnt=zf.Extract(targetPath);<br />
			zf.CloseZipFile();<br />
			return cnt;<br />
		}<br />

BTW -- we are using the GNU Open Source Zip streams in .NET.

_____________________________________________
_{The world is a dangerous place.
Not because of those that do evil,
but because of those who look on and do nothing.}

Re: Using MemoryStream instead of FileStream problem

leppie12-Mar-03 8:32

leppie

12-Mar-03 8:32

Good

I rated this article 2 by mistake. It deserves more. I wanted to get to the second page... - vjedlicka 3:33 25 Nov '02

Accessing controls of one form from another form

Mazdak11-Mar-03 6:57

Mazdak

11-Mar-03 6:57

I have a buuton in my form,when I press this button,another form is open.How can I access controls in first form from second form?

Mazy

"And the carpet needs a haircut, and the spotlight looks like a prison break
And the telephone's out of cigarettes, and the balcony is on the make
And the piano has been drinking, the piano has been drinking...not me...not me-Tom Waits

Re: Accessing controls of one form from another form

Zek3vil11-Mar-03 7:07

Zek3vil

11-Mar-03 7:07

You can access controls in the first form if their modifiers value are set to public

No time to breathe

Re: Accessing controls of one form from another form

Mazdak11-Mar-03 7:33

Mazdak

11-Mar-03 7:33

Really?!!!!!!!!!!!!!!!!!!!!!!!Thats my question.How?!!!!!!!!!I want to do it from second(child) one after it is shown.

Mazy

"And the carpet needs a haircut, and the spotlight looks like a prison break
And the telephone's out of cigarettes, and the balcony is on the make
And the piano has been drinking, the piano has been drinking...not me...not me-Tom Waits

Re: Accessing controls of one form from another form

Zek3vil11-Mar-03 21:13

Zek3vil

11-Mar-03 21:13

I'm sorry, my mistakes, I thought u wanna do it from the first form.

But I found a way that u can try, u can access the parent form's controls this way:

Form.ActiveForm.TopLevelControl.Controls[index]

No time to breathe

Re: Accessing controls of one form from another form

Mazdak12-Mar-03 6:34

Mazdak

12-Mar-03 6:34

Thanks for your help Smile | :)

but this return the control from second form,not parent form. Frown | :(

Mazy

"And the carpet needs a haircut, and the spotlight looks like a prison break
And the telephone's out of cigarettes, and the balcony is on the make
And the piano has been drinking, the piano has been drinking...not me...not me-Tom Waits

Update does not work for dataset

Marix11-Mar-03 4:39

Marix

11-Mar-03 4:39

I have a problem with datasets. The thing is, that i can not update my dataset. What I have is a dataset with 3 tables which I got from access file with oleDbAdapter. My application changes data in dataset, rows become modified, but when I call update method for the adapter nothing gets updated in source tables. No errors, seems that everything works fine, but it is not so.
oleDbAdapter generates my update/insert/delete commands.
I can not find problem. Can anyone help me?

Re: Update does not work for dataset

leppie11-Mar-03 6:24

leppie

11-Mar-03 6:24

I think you need to call AcceptChanges before trying to update.

I rated this article 2 by mistake. It deserves more. I wanted to get to the second page... - vjedlicka 3:33 25 Nov '02

Re: Update does not work for dataset

Marix11-Mar-03 21:47

Marix

11-Mar-03 21:47

I tried, but still does not work! In this dataset there is a table that i need to update which has 4 fields. In appliction I change all fields, and when I call update method jus two fields are updated, but actally all fields in dataset are changed.
Anyway, AcceptChanges marks all modified rows as unchanged, and these rows update method does not take in count, isn't that?

Re: Update does not work for dataset

Marix12-Mar-03 1:44

Marix

12-Mar-03 1:44

Finally i found my problem, i had to use methos EndEdit() before updating dataset!! Smile | :)

))

Re: Update does not work for dataset

leppie13-Mar-03 10:11

leppie

13-Mar-03 10:11

Same problem i had over the weekend. I was gonna suggest checking the databinding then Smile | :)

Textbox problem?

I rated this article 2 by mistake. It deserves more. I wanted to get to the second page... - vjedlicka 3:33 25 Nov '02

C# pipe example

Davy Mitchell11-Mar-03 3:39

Davy Mitchell

11-Mar-03 3:39

Anyone know of a good C# named pipe example?

Davy

Blog for Software Testing, Bugs, Quality, Security and Stability - www.latedecember.com

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Copying NOT Moving a Directory!!!!

jesus4u11-Mar-03 3:13

jesus4u

11-Mar-03 3:13

I want to COPY a directory to another location NOT move it like the code below does.
Does anyone know of such a method call? I searched the help and didn't see anything. OMG | :OMG:

<br />
System.IO.Directory.Move(strSourceName, strDestination); <br />

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