i am working with simple UDP based client server application . The problem i am facing is that theoretically the MTU size of ethernet is 1500 bytes , but when is send more than 1400 bytes of data then the the dataarrival event which is supposed to be called two times is called only once, Now this is confusing as the there should be two time the event be raised
View 1 RepliesWhen you Use Socket.Send Ether in VB6 with the Winsock control or Vb.Net sockets / Windows API does it generate that if you send "Hello" that on the other side it will get the Full Message Before the Data Arrival event is triggered??Or is it possible it can get it in two Different events like "He" & "llo" and a Last question, TCP is stream oriented, is there a Protocol that is Message Oriented but is wrapped with TCP, if not what is a good Delimitor to use with TCP, Usually ide use &H1 OR &H0 but I assume &H0 is common.. or Should I just add a Length Param before each Packet I send..?Now if thats the case and I got the Delimitor route... What if Im sending Chunks of 8192 of a File in a while loop and on a different thread I send a Command if I use the Length Param isent there a huge chance that the messages will get sent like this
[code]...
BUT the issue lies as it thinking that only the 3 of 4 of the incomming file Frames are getting Recv due to it not knowing which frames are for which. Mainly due to me sending a big burst and on the other side recving random chunk sizes on the other side.Edit: Got another question, If I send two bytes across the internet via TCP, will they ever arrive as two different I belive the term is Frame or is that only when they exceide the size of the MTU will the Message be Split. The reason why is if I send a Header saying SOH, Length Of Message(2Bytes), thats 3 bytes can I say 100% of the time the computer on the otherend will recv that all at once so I can parse it? And What ever happen to Flush for Winsock?
Im using TCP cliente to connect and receive data from my server. To read received data im using this code:
[Code]...
It works fine when server response is detected but when there is no connection or there is no server respone the program starts to crash and doesn't work, so i have to break the debuggind process.
I wish to use raw input on an application that i know accepts it and simulate ondevicearrival events for a physical hardware device so i dont have to plug it in to test on device arrival. I can find the pid and other hardware specific numbers if needed for the simulation but im really just wanting to simlulate multiple mice for ondevicearrival.
Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth. - "Sherlock holmes" "speak softly and carry a big stick" - theodore roosevelt.
Example data arrival: 07:05 -!- [URL] 366 name #test :End of /NAMES list. 07:05 -!- etc.... If i debug.writeline the returning value or use a messagebox both will display the out put above. If i try return using an if statement matching against the Nothing keyword. It will still be displayed.
View 8 RepliesI have a Visual Basic Program that, when I enter data into a textbox, uses LEAVE events to update it. However, it will not update until I go to another textbox or press a button or other similar control.This also happens when using the LOST FOCUS event.How can I make the textbox update (be it doing a financial recalculation or some other custom function) happen when the user clicks/tabs out of the textbox and NOT having to click on a button or into another textbox?Do you recommend having a separate button for performing the custom functions?
View 6 RepliesI am having a bit of trouble with using the date/time picker in a project.It is a program for calculating travelodge hotel accomodation prices. The price for a weeknight is 40 but weekends increase to �50.The code which I wrote is this:
For i As DayOfWeek = dtpArrival.Value.DayOfWeek To dtpDeparture.Value.DayOfWeek
If dtpArrival.Value.DayOfWeek = 1 Or 2 Or 3 Or 4 Then
PriceDecimal = PriceDecimal + 0[code].....
It does not work obviously because I am using the date/time picker for arrival date only. I think I need to use some other value which i would presume is something like "If DayOfWeek = 1 or 2 or 3...." but this will not work.
I've read thru Iceplug's tutorial on control arrays and got it working. I tried to add a new event by basically copying his click event code and calling it a doubleclick event. I used the proper addhandler and assigned the correct name to my sub. I have the click event changing the background color to blue and the doubleclick event changing the background color to green. The background color does not change to green. Why?
Heres the tutorial with my new code encased in asterisks ...
Code:
Imports System
Imports System.Windows.Forms
Public Class form1
[CODE]...
I am using VB.NET for Windows applications. What is the difference between Load event,Activate event and Enter event in the Form and in which order the above event is executed.
View 2 RepliesI'm trying to validate a few things in a form I'm building. It has a datagrid with clients info (taken from an access database) and a few textboxes where the user can type some search criteria. The thing is that those same textboxes are used to add new clients to the database and to modify a client's information if one from the datagrid is selected, so I made it that the buttons to insert and modify clients are disabled on load and thenevery time the text on a textbox changes ("TextChanged" event) they become enabled. So far so good. But then I wanted to make it so when a client from the datagrid is selected both buttons become disabled again until the text on a textbox changes (to make sure they're adding a different client and not the same one that was
selected).
I tried using the CellClick event from the datagrid to disable the buttons, but since every time a client is selected from the datagrid the info is shown on the textboxes, this triggers the TextChanged event too, and the buttons become available.So, is there a way I can tell the TextChanged event not to be triggered when the CellClick event occurs?
I read data into a DS from an XML file. The user has the ability to "Save" or "Save As" at any time. They can also "Open" an existing file or create a "New" one. (brilliant, don't you think?)
I need to make sure I ask the user if they want to save their existing data (i.e. rewrite the XML file) if the DS has changed from the XML load or from the last time they Saved. On Open, New or exit I have been checking the HasChanges function on the DS. This doesn't work the way that I need. I use AcceptChanges throughout the program to commit values to the DS. This appears to kill the HasChanges even though the DS is now different than the XML file.
Is there an event in the DS that fires when data changes? If so, I believe I can set a flag that can be checked later. If not, is there any other way to track that a DS has changed after the initial XML load? Would reloading the XML into a cloned DS and comparing the two work? Seems like a waste of "time", especially with large XML files, but if it's the only way.
I'm writing a forms application. I'm adding a piece that allows you to double click on a row of a datagridview control to open a new form with more details. These additional details are pulled from a database, which takes a bit of time to finish.If I run the DB query from the form's load event, the form doesn't show up until everything in the load event has completed, which can take several seconds.I want the form to show up instantly when you double click, and all of the fields to be populated once the data is ready.Is there an event I should be using other than Load?
View 6 Replies<Visual Studio 2008 / VB.NET /SQL 2008>. I have a form that populates data when Load event occurs. The problem is it looks like a slow motion movie when the form is loaded since there some quite amount data is populated. This is happen because I put a coding to populate data on Form Load event. Is there anyway that I can prevent the slowing down of form load event? I guess best thing is load form completely and trigger populating data.
View 3 RepliesI have a program that will load a datagridview with data from a database via a dataset at form load. On this same form, I have a button named "count", that when pressed, I want it to show a message box indicating how many entries were loaded into the dataset.
My question is: How can I get the data from the main window into this click event sub??
or Do I have to fill the dataset again within the Click Event Sub?[code]...
I'm trying to pass a data packet from the serial data received event.The code can capture the data without any issues.I'm spinning my wheels on getting the data packet out of the thread for further processing.[code]
View 4 RepliesI need advice on how to pass the details of a double clicked datagrid record to another form and display as text boxes etc. This will act as an edit form for the user once they have clicked their desired record.
View 1 RepliesI want to create a textbox which contents are validated every time the text in it changes. And an image is displayed beside the textbox if it is correct and another image shows up if its not correct. Pretty much like ajax.
Heres the method which I called from the class.
Public Sub read1()
cmd.CommandText = "SELECT * FROM testdb WHERE Name='" & name & "'"
Try
[Code]....
Problem is, the method seems to be only called once. And the first image that was displayed stays the same even after inputting a data which does not exist in the database. I'm connecting this program to a mysql database using odbc.
If I wanted a character in a datagridviewcolumn replaced when it's typed, not when the cell is left, how could I achieve that? Is there an eventhandler tied to that?
View 1 RepliesI have three tables set up in a MySQL database called "event", "status" and "user". (as shown below:
EVENT TABLE (below)
STATUS TABLE (below)
USER TABLE (below)
and when I get data from the event table I use the SQL query statement below to bind the persons first and last names together as one variable called "name" and then bind that name to the respective user_id; and so on. However when I make changes to the event table it doesn't show the changes I've made. I'm certain it has something to do with the way I'm retrieving the data.
SELECT CONCAT(u.lastname, ', ', u.firstname) AS Name
, s.message AS Message
, DATE_FORMAT(e.timestamp,'%b %d %Y - %r') AS DateTime[code].....
I am developing application which will read credit card no without generating keystrokes for same in POS for .net. I can enable device but when I swipe a card MSR_Dataevent is not firing. EDIT: I have done below code:
[Code]...
i have a textbox that i want to format the value and i placed it in the Validated event.. it works ok when a user enters a value but when data is being loaded from database, it doesn't format.
View 12 RepliesI had built an application such like items management, I used two table in two different database in two different engine server, the stack is, when I want to make event for add new data, how I can make the event for the combobox ID for switching it's datasource from before.. for the knowledge, the first table is Xtable, database is Xdatabase and the machine is Xmachine; and for the second one is : table is Ytable, database is Ydatabase and the server machine is Ymachine...
View 1 RepliesI have a class that I want to handle it's own events but still have the instance inherit it.for instance I want the event to display in a text box but from class level.[code]
View 12 RepliesAs it stands, when I click a button to load the data the application lags and looks as though it has locked up although it has not. There are a lot (10,000) of records to load in some cases.
I thought I could just change my status strip text to dispay "Loading database" while it's loading.
So, I raise an event (dbloading) in the "load db" button.click event before calling the procedure to load the data. When that event is raised, I change the status strip text.... but it does not work.
Here's my
Private Sub btnLoad_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnLoad.Click
jnATM = Me.atmJobNum
[Code]....
I am trying to get my grid to refresh automatically when the underlying data is updated in the database. Isn't this supposed to work? Or am I missing something? I created a DataTable within my DataSet. Then I created a new form and added a DataGridView (actually I'm using DevExpress' XtraGrid but am trying to get it to work with just the Microsoft controls). I use the menu in the upper left of the grid to set the grid datasource to the datatable in the project data source. This then automatically adds the dataset, BindingSource, and TableAdapter to the form.
[Code]...
I am using VB 2008 Express to connect to an Access 2007 database. I have a combo box that is populated by the database. When I used the Access report VBA, I used the AfterUpdate() event to calculate a sum and place the results in a text box. I need to know how to do the same operation in VB 2008 Express using the SelectedIndexChanged event of the combo box.
The combo box is called "cboYearMonth" and is populated by my database, this is working correctly.
The text box that I want the calculated results to appear in is called "ExactPagesTextbox"
I have a query in Access called "JobTypeExact_Query" that contains all the pages that I need. What I need to do is calculate the total number of "Pages" limited to the YEARMONTH selected in the combo box. YEARMONTH is a value in every record in this query.
On SqlDataSource_Insert, I'm grabbing the users unique MemberID and adding to the db. Adding the MemberID works great. I also want to add a unique EventID for the event they are submitting, but the code that I'm using below just inserts a guid with all zeros.
Protected
Sub SqlDataSource1_Inserting(ByVal
sender As
[Code]....
I have a datagridview which is populated from a database. I have added buttons to this to edit, view, delete. For some reason using the edit button and updating the database my grid fails to respond. I have it set up to display an image based on the row I click on. Before the update this works, after is does not. After the update I run a reload() where I clear out the dataset and repopulate the datagridview. Here is the code I am using for the reload and the update.
Public Sub reloadDG()
'reloadDG is used to clean out the information currently in the datagridview and is replaced with
'current data
'calls refreshForm()
[code]....
I use VS2005 and visual basic. I have a SaleDetail table has the following fields:
[Code]...
created a control inheriting a textbox. it is used to format a datetime data. i created a custom property DateTimeFormatMask which is "MM/dd/yyyy" by default. problem i'm having is that when datatable is filled by adapter and the textbox is populated with the data, it is not formatted..i placed the codes that formats the data in the Validating Event which doesn't seem to be triggered at this point.below is my code on my
View 4 Replies