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BeginInvoke is not needed as the Show is not going to block any threads. Just call MainForm.Invoke with the delegate to show the newForm. eg.
Thread thread = new Thread(new ThreadStart(StartNewThread));
thread.Start();
}
void StartNewThread(){
this.Invoke(new MethodInvoker(this.LaunchForm2));
}
void LaunchForm2(){
Form2 frm = new Form2();
frm.Show();
}
I know as a standalone example my code would be daft, why start a new thread just to invoke back to the original thread, but I assume you are doing some other processing in the secondary thread to make it worthwhile.
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I'm not sure about the best practices where this is concerned. It's not something I would ever do so I haven't investigated and could maybe have some disasterous consequences. A quick test however reveals it works - I'm sure others will comment!
using System;
using System.Threading;
using System.Windows.Forms;
namespace Forms_Test
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
Load += new EventHandler(Form1_Load);
}
private void Form1_Load(object sender, EventArgs e)
{
Thread thread = new Thread(new ThreadStart(StartNewThread));
thread.Start();
}
private void StartNewThread()
{
Application.Run(new Form2());
}
}
}
Edit: This MSDN[^] link may be of interest.
DaveIf this helped, please vote & accept answer!
Binging is like googling, it just feels dirtier. (Pete O'Hanlon)
BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
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It works, but ugh!
The main message loop that started Form1 will end when that closes, fire any application clean-up code you wrote and leave Form2 orphaned.
It is a bit like firing up another application using Process.Start . Form2 would have to be treated as a separate application and the start thread must do all the usual stuff you need to run, and shut down an application. On the down side, they would reside in the same AppDomain and a crash in either thread would then kill both, also communication between the parts would be a nightmare.
I'm not sure how they manage it, but I guess Office does something similar for Word and Excel etc. where it appears to fire up a new instance of Word for each document, and they can be closed independently, however only one process is running.
Interestingly in the browser world things are moving the other way, eg. Google Chrome runs each tab in a separate Process, so you get one apparent application but multiple processes!
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Agreed - hence the caveats I placed in there.
DaveIf this helped, please vote & accept answer!
Binging is like googling, it just feels dirtier. (Pete O'Hanlon)
BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
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You could post an (custom) event that the main form responds to, and let the main form create the modelss window...
.45 ACP - because shooting twice is just silly ----- "Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997 ----- "The staggering layers of obscenity in your statement make it a work of art on so many levels." - J. Jystad, 2001
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private void button1_Click(object sender, EventArgs e)
{
System.Threading.Thread t = new System.Threading.Thread(
new System.Threading.ThreadStart(delegate
{
Form1 frm = new Form1();
frm.ShowDialog();
}));
t.Start();
}
That seems to work for me.
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It may work for you, but it's not going to work in all instances and environments and it WILL produce bugs that are difficult, if not impossible, to track down. The short answer is you just don't put up UI elements on anything other than the UI thread.
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Dave Kreskowiak wrote: it WILL produce bugs
You sure about that? Do you have a concrete example?
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There's no such thing as a "concrete" example of this.
All you have to do is ask around.
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Word on the street, huh? Oooooo....k.
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Ask around HERE. You want the professional experience behind it? Ask around HERE. Don't take just my word for it. Ask everyone with an MVP icon next to their name.
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Ask anyone who have ever done anything with threading.
The most common bug I come across where I work is anything accessing the UI from another thread, either creating stuff, or just calling methods and properties across threads.
It is worth noting that the debug environment runs in a rather safe mode (somehow) and so threading issues rarely show up during development, unless they are really bad. Worse, you cannot step through them easily as the timing of actions on different threads makes a big difference.
In my experience 50% of threading issues break the application on the first time they are run in a release environment. Of the other 50% it depends on the hardware and network environment. We had a threading issue that only came to light a year after release when the end user upgraded their machine. Suddenly one of the threads ran faster (probably off on another core, or just from the faster processor) and the bug climbed out of hiding.
World of pain!
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Bug number 1.
You used ShowDialog which should produce a modal dialog, however it is modeless, due to running on a separate thread. Therefore you can spawn hundreds of these secondary dialogs, oops. Not an execution bug in this case, but clearly a process flow bug. Having said that changing your code to Show doesn't produce any visible form at all.
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Hello,
I try to add OpenFileDialog to my code and i can not.
What to do?
**I develop in console NOT in WindowsForm
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Yes, well a console application is not supposed to have GUI, does it?
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A console app starts its execution in a console, it may however turn itself into a regular WinForms app; there is nothing that prevents it from creating and showing Forms. The opposite is not possible: a WinForm app cannot perform input/output operations through the console if it were launched from a "DOS window" or a "Command Prompt" window (it can use a console, but that will not be the same as the launch window).
The problem the OP is probably facing is there is no using System.Windows.Forms; statement included automatically, so he should add that first if he wants to create Forms by code. The context menu "Add Windows Forms" however is available in the solution pane.
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 know. But in this era, if you build a console app, you're planning to be non-interactive right? I mean you'll happily accept stdin, stdout, all the pipes in the world, and even if you want to build a service, you won't put up a dialog will you? I know even Microsoft does this (misuse of MessageBox, shutdown /I interface), but if you're writing console, you're writing console. I only use console if I plan to run on posix, or target server core, or do a quick test where I don't want be bothered by drawing forms). I think it's a base choice: either you'r scriptable, and you go for console, or you're point-n-click.
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I disagree, there may be good reasons to create a hybrid. What I would like to do is write a single app (one EXE) that:
- when no command line arguments are present, behaves like a WinForms app, i.e. it offers a GUI and the user can start setting options and clicking buttons;
- when command line arguments are present, behaves like a Console app, i.e. perform its job, as defined by the command line arguments, and provide output to the console, so it can be embedded inside a batch file, its output could be redirected by the shell, etc.
All this without a console nor a WinForm form popping up for a fraction of a second, to be hidden again when it is not wanted.
Turns out Windows does not let one do that. There is a single bit in the EXE format (PEF) that says this app is a console, if not started from a console, open one; or it isn't, so don't give it access to its caller.
Example:
I like WinZip a lot; long ago it was a DOS utility, no GUI, just command line operation. Fine.
Then it turned into a WinForm app, with a GUI.
And then they fixed it, by adding a "command line extension", a second EXE to fix the lack of scriptability. So MS themselves need two EXE to do basically the same thing twice, with different user interfaces.
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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MS is moving more to a 'Unix/Linux like model'. Important system utilities, like diskpart, ipconfig, increasingly have no user interface. Even worse, most of these utilities are implemented twice: in the diskpart example, you have the diskpart.exe, which does some (more) things than the storage management in msc. But both rely on background or system services to do the job. The GUI is there for the casual user, who just wants to get the job done once, the console app is there for the sysadmin who wants something special, or needs scriptable deployment.
There's always a tension between 'ease of use' and 'advanced functionality'. Some functionality cannot be expressed in GUI terms, but may be obvious to the sysadmin with some programming experience.
That's always been my gripe with Unix/Linux systems: pulling up a man page gives me information on how to run the Large Hadron Collider, but I'd be buggered on how to delete a file with a space in the filename in my home directory.
I suppose it's a choice, but I think supplying two utilities for the same job (one graphical for the casual user, one performing for the expert) is a good choice.
Another philosophical discussion
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Michel Godfroid wrote: I suppose it's a choice
At the very least, it is a choice I want to make myself; not have somebody else make for 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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Michel Godfroid wrote: gives me information on how to run the Large Hadron Collider, but I'd be buggered on how to delete a file with a space in the filename in my home directory
Apple probably 'have an app for that' too!
DaveIf this helped, please vote & accept answer!
Binging is like googling, it just feels dirtier. (Pete O'Hanlon)
BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
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Hi Luc, not for you but for anyone viewing who may wish to know how...
Luc Pattyn wrote: it can use a console
Clickety[^]
DaveIf this helped, please vote & accept answer!
Binging is like googling, it just feels dirtier. (Pete O'Hanlon)
BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
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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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Yes u can do his with System.Windows.Forms namesspace
go through the below sample code
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace test
{
class Program
{
static void Main(string[] args)
{
OpenFileDialog ofd = new OpenFileDialog();
ofd.ShowDialog();
}
}
}
Rajesh B --> A Poor Workman Blames His Tools <--
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As others have mentioned, you need to add the line
using System.Windows.Forms; to your code.
I would also clarify you need to add a reference to the System.Windows.Forms assembly in your project (since this is not automatically included in a console project).
Dybs
The shout of progress is not "Eureka!" it's "Strange... that's not what i expected". - peterchen
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