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you could always fill a memorystream with legal HTML code, then feed that stream to WebBrowser.DocumentStream. HTML knows how to package an image, a PDF, etc; web servers do it all the time, e.g. when you browse to http://www.codeproject.com/App_Themes/Std/Img/logo225x90.gif you well get Bob, because the CP server sends the correct HTML head and body stuff.
Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles]
I only read formatted code with indentation, so please use PRE tags for code snippets.
I'm not participating in frackin' Q&A, so if you want my opinion, ask away in a real forum (or on my profile page).
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Thanks again Luc,
But.............
what is the HTML code you are talking about?????
what is the HTML code that represent file's binary data??
You may mean < embed ... ???
if so, I must save file to hard disk that is I do NOT want to do
this is my question 
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You don't need a physical file; most file operations also exist as stream operations (see e.g. Image.FromFile and Image.FromStream), and a MemoryStream is a Stream. So WebBrowser.DocumentStream should be your friend.
For HTTP, there are a number of classes in .NET; and there is the full HTML specification. I have done some on server side (mostly PHP, where lots of library functions are available, which hide the details); I also once found Sample HTTP Server Skeleton in C#[^] quite interesting. It may actually be what you want: it allows you to hide a web server inside your app, so your WebBrowser (or any external browser on your machine) could see its web pages, which do not exist outside your process.
Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles]
I only read formatted code with indentation, so please use PRE tags for code snippets.
I'm not participating in frackin' Q&A, so if you want my opinion, ask away in a real forum (or on my profile page).
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Luc Pattyn wrote: you could always fill a memorystream with legal HTML code
Are you really certain for that?In that case if you want to diplay pdf file you need web server to handle requests to the database.WebBrowser control has a property DocumentType , which contains mime type of the document.And if we need pdf we could just set it to "application/pdf" and IE will understand that this is pdf file, not html page.
[Edit]It's read only unfortunately.After after googling I've found that.[/EDIT]
Life is a stage and we are all actors!
modified on Thursday, June 10, 2010 12:52 PM
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Not sure what your question is. To the OP, I see two possible paths:
1. feed an entire MemoryStream to WebBrowser.DocumentStream, by synthesizing a valid HTML response;
2. or provide an embedded HTML server, and use WebBrowser.Navigate().
In both cases, the data could be provided by any means available, such as a database.
Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles]
I only read formatted code with indentation, so please use PRE tags for code snippets.
I'm not participating in frackin' Q&A, so if you want my opinion, ask away in a real forum (or on my profile page).
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My post means that you can't display pdf in web browser control from binary data, loaded from a database for example.And the forum thread said that you can't set DocumentType property but you could work around that by hooking IE session.I believe it's ultimate hack.
Life is a stage and we are all actors!
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I'm pretty sure it can be done, as I have said several times already.
Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles]
I only read formatted code with indentation, so please use PRE tags for code snippets.
I'm not participating in frackin' Q&A, so if you want my opinion, ask away in a real forum (or on my profile page).
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Luc Pattyn wrote: to prove it (for an image; a PDF would be similar).
Yes if the pdf is located somewhere on the web.But if it's binary data loaded from local db there's only one way, which is closer to dirty hacks instead of normal logic.
Life is a stage and we are all actors!
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What is wrong with you? simply copy whatever binary data you have from the database to a memory stream, then feed the WebBrowser; it will consume everything it understands (HTML; XML; plain text; lots of image formats; PDF).
PDF will only work well if you thaught Internet Explorer to handle PDF files (e.g. with an Adobe component); if it doesn't, neither will WebBrowser.
Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles]
I only read formatted code with indentation, so please use PRE tags for code snippets.
I'm not participating in frackin' Q&A, so if you want my opinion, ask away in a real forum (or on my profile page).
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Luc Pattyn wrote: PDF will only work well if you thaught Internet Explorer to handle PDF files
Yes you are right only for images handing.It't NOT working with PDFs as it was already mentioned.Simply try that and see with your own eyes what is displayed-the pdf file or something else:
byte[] binarydata = File.ReadAllBytes(@"C:\somefile.pdf");
MemoryStream str = new MemoryStream(binarydata);
webBrowser1.DocumentStream = str;
The problem is that you can't set DocumentType property and IE can't handle Content-Type header automatically.You need to set it somewhere, but you are not able using DocumentStream property only.
Life is a stage and we are all actors!
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Yes, you are right, PDF is different after all. Some research indicates PDF is harder than images, but doable. I'll try to demonstrate when time allows me.
Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles]
I only read formatted code with indentation, so please use PRE tags for code snippets.
I'm not participating in frackin' Q&A, so if you want my opinion, ask away in a real forum (or on my profile page).
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Hi Luc,
I think you and the OP are miscommunicating. Let me see if I can help to clear things up. Say you want to display a PDF in a WebBrowser control. You'd have to 1) have some HTML that makes uses of <embed> to point to a PDF and 2) have that embed tag point to some location that is storing the PDF. Now, if the application making use of the WebBrowser is entirely local, it would be impossible to, say, serve up a PDF file when a certain URL is hit (that would solve the problem of using a stream to serve a PDF, but only if the OP has access to a web server). Now, if the user wants to do everything on the client side without any file access or remote URL access, then it seems there may be a problem displaying the PDF. The OP is claiming that images can be directly displayed by a WebBrowser control (i.e., by passing the memory stream to the WebBrowser) but that the WebBrowser is incapable of displaying a PDF, except for via an <embed> tag. If you use the EMBED approach, you have to point to somewhere, and that somewhere can't be a memory stream.
By the way, the tip/trick you made doesn't work for me. I just see an "X" displayed where there should be an image. Not sure why that is. Perhaps the type of data needs to be specified somehow (usually this would be provided by the server in the HTTP header, but there is no HTTP header AFAIK when you set the WebBrowser control to use a memory stream).
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Thanks for your effort, however it did not change my view on things, so maybe I misunderstood both of you now, or, well, I don't know. I'll try to summarize the main facts so far:
1.
I understood the OP wants to see local data (images, PDF, whatever) which is stored in a database rather than in individual files, and wants to avoid the use of temporary files. I take it all he wants to see is one data object at a time, not a composition of some HTML and one or more database data objects. I am assuming all data types are popular types known to web browsers. If not, special viewers would be required (e.g. a HEX viewer for unstructured, "meaningless", binary data.
2.
The Tip&Trick works fine on my system, which has Vista-32, IE7 as original browser, FF3 as default browser, and using a .NET 2.0 debug build. So I would be inclined to say images cause no fundamental problem, provided they use a format WebBrowser recognizes AND understands (such as GIF).
3.
I have no idea yet what could go wrong for you there. I tested the exact code as published inside a pre-existing WinForm application. So I have some questions for you:
(A) did you change the code at all?
(B) what are your system's characteristics?
(C) Knowing the WebBrowser's size is 500*500, how large is the "X"? I assume it is red?
4.
If the OP uses my T&T code and replaces my synthetic image by some data read from his database, images should work.
5.
Hristo Bojilov signaled PDF would not work that way, and indeed PDF seems more complicated; IE and FF successfully load and display a remote PDF (when typing an URL in the address bar), WebBrowser also successfully navigates to the same PDF file, but fails to recognize a PDF when simply feeding it in its DocumentStream. It then simply shows the bytes as text. Some research has led to two complex ways around it, one of them is an article here on CP; the basic idea is to help WebBrowser in recognizing PDF files and selecting the right way to handle them, and so it is not based on an EMBED or OBJECT tag, as they would require a file. I haven't tested these yet, I have more urgent matters right now.
6. "but only if the OP has access to a web server"
I once created an embedded web server; it basically is a class one adds to an existing project; it takes data and produces web pages (that part of course needs customization), available on localhost at some port number. Doing so enables any WinApp to make data available to a browser running on the same PC, possibly a WebBrowser within the same app. As it basically uses WebRequest/WebResponse classes, it can provide data as well as data type information, so that should suffice to deliver all popular data formats without requiring files. It is pretty complex though (ca.300 LOC), way too large for a Tip&Trick. I would have to test it again for images and PDFs, but it looks like one way to get it all solved.
7.
I also once did some PDF server/client work a few years back, alas all in PHP and based on a couple of PHP libraries, which means impossible to port in a jiffy. I'd rather not go that route.
Conclusion:
- it is work in progress
- please correct me if you disagree with any of the above
- and please provide answers to the questions in (3), about the T&T not working for you.
Cheers.
Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles]
I only read formatted code with indentation, so please use PRE tags for code snippets.
I'm not participating in frackin' Q&A, so if you want my opinion, ask away in a real forum (or on my profile page).
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I need to save the selected row and the vertical scrollBar's position after a refresh. This is how I do it:
int currRow = myGrid.CurrentRowIndex;
int vScrollPos = ((ScrollBar)myGrid.Controls[1]).Value
myGrid.CurrentRowIndex = currRow;
myGrid.Select(currRow);
((ScrollBar)myGrid.Controls[1]).Value = vScrollPos;
Here's my problem: The grid always jumps to a place where the selected row is at the bottom. 'Select' does exactly that (similar to EnsureVisible of newer grid implementations). But after that there's the vScrollBar repositioning - and it just does nothing. In debug I see the scroll bar value gets updated. In the UI, if I hit the down/up arrow the scrollbar suddenly jumps to where it should have been according to it's updated property - But if I don't click anything the grid is just in the wrong position. I tried refreshing the grid/scroll bar to force a redraw, but it doesn't help. This is really frustrating, as the code is right there and it just doesn't comply
Thanks for your help.
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I am creating an installer where i need to install SQL server express.
i am doing this with help of a bat file. But i am getting an error, saying that..
One installer is running so i can't run another one.
My Question is. How can i install sqlserver express at the time of installation of Application.
Thank you
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Hi,
Let's say there are 3 objects:
Class A
Class B : A
Class C : B
I want to pass through all objects that derive from Type B
C obj1 = new C();
B obj2 = new B();
if(obj1.GetType() == typeof(B)) {
//--Pass through all objects that derive from object B or object A...
}
typeof comapares directly the top types C must equal C... No polymorphic comarison...
How to do a polymorphic comparison? Which keyword or mechanism to use?
Thanks!
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if(obj1 is B) should work for you
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As lukasz_nowakowski says, is is what you want. The alternative is as
if (obj is B)
{
B bInstance = (B) obj;
...
}or
B bInstance = obj as B;
if (bInstance != null)
{
...
}You can use either, I prefer the second as I prefer explicit null tests. That's just personal preference though.
Did you know:
That by counting the rings on a tree trunk, you can tell how many other trees it has slept with.
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If you want to just add it to objects' list, then is is enough, but if you want to use object obj as instance of class B, then B instance = obj as B; is the path to follow. To find out why read for example this[^].
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The work with polymorphic objects after comparison is very clear to me.
I just didn't know how to compare them in C#...
Thanks!
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FYI - while the use of is and as are what's appropriate for your problem, as lukasz_nowakowski and OriginalGriff have said, your example code used GetType ... which put me in mind of how to do a similar test on Types, rather than objects:
Type typeOfC = typeof(C);
Type typeofSomeObject = someObject.GetType();
if (typeOfC.IsAssignableFrom(typeofSomeObject))
{
}
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Hello everybody!!!
we have a problem with crystal reports and c#.
we would like to pass the data to the report directly with parameters, but we don't know how to add the pages in the report.
this is the code we have. we pass the parameters to the report witin a forreach, but we just get a report with only one page and with values of the last row of the dataset in the report.
Any idea please???
try
{
SqlDataAdapter daCategory = new SqlDataAdapter();
daCategory.SelectCommand = new SqlCommand();
daCategory.SelectCommand.CommandType = CommandType.StoredProcedure;
daCategory.SelectCommand.Connection = kon.SqlConn;
daCategory.SelectCommand.CommandText = "asp_admin._DatosReport";
SqlParameter parameter = daCategory.SelectCommand.Parameters.Add("@numero", SqlDbType.Int);
parameter.Value = instalazioa;
parameter = daCategory.SelectCommand.Parameters.Add("@Fecha", SqlDbType.DateTime);
parameter.Value = Convert.ToDateTime(FechaElegida);
DataSet ds = new DataSet();
daCategory.Fill(ds, "Termico");
if (ds.Tables["Termico"].Rows.Count > 0)
{
ParameterValues CurrentParameterValues = new ParameterValues();
foreach (DataRow rw in ds.Tables["Termico"].Rows)
{
NInst = new ParameterDiscreteValue();
Rep = new ParameterDiscreteValue();
Dev = new ParameterDiscreteValue();
datosActuales.NInstalacion = Convert.ToInt32(rw["NInstalacion"]);
datosActuales.NRepetidor = Convert.ToInt32(rw["NRepetidor"]);
datosActuales.NDevice = Convert.ToInt32(rw["NDevice"]);
//meter los valores de las variables
NInst.Value = datosActuales.NInstalacion;
//reporte.SetParameterValue("Instalacion", NInst);
Rep.Value = datosActuales.NRepetidor;
//reporte.SetParameterValue("Rep", Rep);
Dev.Value = datosActuales.NDevice;
// reporte.SetParameterValue("Dev", Dev);
CurrentParameterValues.Add(NInst);
CurrentParameterValues.Add(Rep);
CurrentParameterValues.Add(Dev);
}
}
}
finally
{
kon.closeConexion();
}
//se crea el report en pdf
reporte.ExportToHttpResponse(ExportFormatType.PortableDocFormat, Response, true, "Termico");
}
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