How can I get things from website

[JKSH]

@victor-wang said in How can I get things from website:

If it is how can i judge the signal and where do i have to add the function in?

You make a signal-slot connection, using QObject::connect(). When the signal is emitted, the connected slot will run automatically.

This is a core feature of Qt. I recommend you spend some time to do tutorials to understand how to use signals and slots.

For the first of debugging and testing.
I will get this on my browser. here

OK, good. That means the server will give you text data.

For the second one, i'm not quite sure what does that mean.

Your code has QUrl("http://192.168.100/59/..."). Change this to QUrl("http://lists.qt-project.org/mailman/listinfo") for testing.

For third one, what does"QNetworkRequest constructly correctly"mean?
I thought i am using the library that Qt have already constructed.

When you call QNetworkRequest(QUrl(...)); you are constructing a QNetworkRequest.

Let's check that your QNetworkReply is what you expect. Put this in your replyFinished() slot:

qDebug() << reply->isFinished();
qDebug() << reply->error();
qDebug() << reply->request();
qDebug() << reply->url();
qDebug() << reply->rawHeaderPair();

For forth one, I'm sure i am on the same subnet because i can send this commend to my console

wget http://192.168.100.59/PLMS/TestCheck.asp?LSN=201503003009&EmpId=we9999&CPID=OS&CPKey=95Z0000000AF

And i will get the file and the content will show "updated ok".

OK, good.

[J.Hilk]

@victor-wang

for your Xming copy/paste problem to windows, take a look to this topic:

https://superuser.com/questions/440128/xming-clipboard-only-works-one-way

That should enable you to poste your code as text for us and not as pictures.

[victor wang]

@JKSH
I add the qDebug in the replyFiniched() slot but i got some errors.
Here

Why is this happened?

[victor wang]

@JKSH
I have try to get from the Url which you gave me for test.
And i will get this information here.

So is that mean the code is not wrong?

[JKSH]

@victor-wang said in How can I get things from website:

@JKSH
I have try to get from the Url which you gave me for test.
And i will get this information here.

So is that mean the code is not wrong?

Yes, your code is working correctly. Go to http://lists.qt-project.org/mailman/listinfo using your browser and view that web page's source (Ctrl+U in Google Chrome) -- it's the same as your last screenshot.

Your code is not wrong. Your device (192.168.100.59) probably returns data in a different way. Fix the errors below to investigate.

@victor-wang said in How can I get things from website:

@JKSH
I add the qDebug in the replyFiniched() slot but i got some errors.
Here

Oops, sorry... QNetworkRequest can't be printed through qDebug(). Just delete this line: qDebug() << reply->request();

The other one should be rawHeaderPairs(), not rawHeaderPair()

[victor wang]

@JKSH

I had change the Url back to the original one.
And i get this

Is that mean i had receive something?
If it is why i didn't see any file that should get from the Url?

[JKSH]

@victor-wang said in How can I get things from website:

@JKSH

I had change the Url back to the original one.
And i get this

Is that mean i had receive something?

Yes.

If it is why i didn't see any file that should get from the Url?

Because your code contains the wrong URL. You want LSN=201503003009, right?

[victor wang]

@JKSH
Actually, if i connect success the URl i set will have the record.
But i just check it, there is nothing on it.
I don't know what to do now.

[victor wang]

@JKSH
I solved the problem!
I 'm too stupid that i type the wrong vocabulary.
It's Empid not Empld in the Url.
Thank you so much for all your help！

[victor wang]

@JKSH
There is another questions.

manager->get(QNetworkRequest(QUrl(http://www1.winmate/PLMS/TestCheck.asp?LSN=201503003009&Empid=we9999&CPID=OS&CPKey=95Z0000000AF)));

what if the Empid is not the static one.
It will let the guest type there own id.
If i want to doing that how can i do it?

Can i type like this?

manager->get(QNetworkRequest(QUrl("http://www1.winmate/PLMS/TestCheck.asp?LSN=201503003009&"+"Empid="+ID"&CPID=OS&CPKey=95Z0000000AF")));

[jsulm]

@victor-wang You can do it like this (Empid= can be just part of the first string - no need for +"Empid=").
Take a look at http://doc.qt.io/qt-5/qstring.html#arg

[victor wang]

@jsulm @JKSH
I've got another question!
I have 10 different Url wanna connect and get information down.
And i'm using for() to do it.Here is my code.

But it will crash and will not connect to the server.
I assume that it because for() is doing too quick.
So i add this inside the case

reply->isFinished();

But it will crash in the beginning.
What else method can i try or what to fix in my code?
Do i need to add the switch case into replyfinished() slot instead of connect?

Please help!

[jsulm]

@victor-wang The problem isn't that for loop is too fast (how could it be too fast?).
Starting with case one you have:

reply->isFinished();

How do you initialize reply? Most probably it is not initialized and you're dereferencing dangling pointer.
Second question: why do you call isFinished() on reply? isFinished() is a getter method which you can use to check whether the reply is finished or not. But you do not use its return value, so the call is completely useless.
In general: if your app is crashing you should first debug it before asking in a forum.
So, please remove that useless reply->isFinished(); and debug your code to see where exactly it is crashing and why.

[J.Hilk]

@victor-wang
To add to @jsulm :

make a make a proper Network function something along the line of:

void getUrlData(QUrl url){
//Do Stuff to call data from one URL
}

Place all your QUrls(10?) into a QList<QUrl>

Now link the IsFinished Signal of your reply to Funktion to call the next URL request from your list.

Dont forget to add a cancel condition, when you reach the end of your list.

Now, start the download chain by calling the first element of your list by hand/button clicked.

[victor wang]

@J.Hilk
Is that mean that i have to connect IsFinished signal and getUrlData slot in the replyFinished() slot?
What is that mean put in the QList?
There is no IsFinished () signal for reply, just have finished signal.

[victor wang]

@jsulm
But how can i get 10 times of different Url.
What should i connect signal?

[jsulm]

@victor-wang What do you mean? You do the same: connect finished() signal to your slot. In that slot (which you already have) you can get the URL from the response to know for which URL this response is coming.
QNetworkAccessManager can handle many requests in parallel - no need to do something special.

[victor wang]

@jsulm
https://forum.qt.io/topic/77186/how-can-i-get-10-different-url

This is my new topic and i had describe it.
I will describe here for you again.
Please help.

i will send this commend for 10 times in the different CPID.

CPID="TOUCH";
URL="http://192.168.100.59/OLMS/TeskCheck.asp?LSN="+LSN+"&Empid="+EMPID+"&CPID="+CPID+"&CPKey=XXX";
manager->get(QNetworkRequest(QUrl(URL)));

But during the process it will return 500 instead of 200 and can't connect to the Url for the few times.
How can i solve this problem?

[jsulm]

@victor-wang HTTP 500 status code means: "500 Internal Server Error".
You should check using a browser whether these URLs are working.

[victor wang]

@jsulm
I'm sure it is worked because if i have just connect that one, it will work correctly.
But if it's in the loop and is not at the first one, sometimes will failed but sometime will success.
So that's why i doubt that because it sending too quick that the server cannot catch it well.