If the new object to set, is structurally distinct of the previous one, set the property grid to a new one(oldpropertygrid = new PropertyGrid;), then set the selected object.
If you run the application from the Visual Studio (F5), is it working fine? If yes,
* Inside the application source folder, did you found any exe file? If yes, ** Is it located in a folder called bin? If yes, *** Did you found any other files like .dll or .res in the same folder?
* Did you created an installation project to deploy the application? If yes, ** Did you tryed to deplñoy in a test pc other than developper? If yes, *** There where errors? *** The deployed application starts?
Any additional info you can provide will be helpful.
You need to have almost to threads (or processes) to handle this situation 1) You'll need an interrup server for each source that will receive each interrupt and add the relevant info into a list. During the process of the interrupt you need to discard any other call to the same interrupt using a processing flag. 2) The second will verify if the list is not empty to get the info from position 0 in the list, remove this position from it and process the relevant interrupt (maybe you need a backgroud worker for that process). In this thread, do not forget to call as many DoEvents as you can.
In order to manage the list, you will need an object (generic) to be locked by each process to access the list, then free it.
The list can be an inmemory list or, if you need persistence, and the response time is enough fast, you can use a table in a database to handle the list.
Assume you have a text file in the path \\MyServer\MyShare\Myfolder\MyFile.txt
var PathToTheFileInTheServer = "\\\\MyServer\\MyShare\\Myfolder\\MyFile.txt";
var sourceFileInfo = new System.IO.FileInfo(PathToTheFileInTheServer);
Then you should be confident than source file exists
if (!sourceFileInfo.Exists)
{
// nothing can be done
return;
}
You can use ...
var tempFolder = System.Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData) + "\\" + System.Windows.Forms.Application.ProductName;
to obtain an application temp folder path within the local application data folder. Then with
var dirInf = new System.IO.DirectoryInfo(tempFolder);
yu'll get the info about this temp directory. Then, if the directory does not exist, you must create it using
if (!dirInf.Exists){
try
{
dirInf.Create();
}
catch(Exception exception)
{
// show a message box explaining the error or take any relevant action
// in theory, you should be able to create it
}
}
Then you need to delete the destination temp file if already exists
var destinationFilePath = tempFolder + "\\" + sourceFileInfo.FileName;
var destinationFileInfo = new System.IO.FileInfo(destinationFilePath);
if (destinationFileInfo.Exists){
try
{
destinationFileInfo.Delete
}
catch (Exception exception)
{
// show a message box explaining the error or take any relevant action
// in theory, you should be able to delete it
}
}
Then you can copy the file to the temp folder
try
{
sourceFileInfo.CopyTo(destinationFilePath);
}
catch (Exception exception)
{
// show a message box explaining the error or take any relevant action
// in theory, you should be able to copy it
}
The difference, in the tests i did, is that the ConfigurationSettings.AppSettings is always returning an empty array (??), so it is currently compiling without error, but not working to me (VS2010 .NET 4.0).
The open mode default option is Open or Create. The access default option is Read-Write. The file share default option is None.
When you launch a process with a file name, the OS searches for the default application to open the file, then applies the defaults to open the file with the application. This is by OS design.
If you need to opena file in 'shared' mode, you must specify it.
The second way:
If the user should not change the file contents, it can be copied into a temp folder and openen it from there (you will preserve the original from being modified).
Alternative: You will need 2 (or more) users modifying the same file, at the same time. Unless it is a database, IMO, there is no way.
You can mark the server file as readonly. This will permit to be read by more than one client at a time.
Another way: Copy the server file in to an application temp folder in the current user profile and launch it from local. The temp folder can be cleaned at application shutdown and/or start.
Any instantiable object can have his own instantiated dataset. Ie: each form in an application can have his own dataset. When you write var f = new form1; a new instance of the form is created and, if the form has a var ds = new dataset; this willalso be instantiated with th form.
The datasets ca be passed by reference so there is no problem to deal with several public datasets from instantiated objects. Any way, i am almost sure you can define a
You start a loop to launch 1024 threads. After each thread is started, you freeze your thread working for 100 miliseconds. Then you try to finalize the launched thread and freeze yours until the thread finishes. And start over for 1024 times.
I would suggest: 1) instead of freezing your application for 100 miliseconds, replace it by a System.Windows.Forms.Application.Doevents, to allow others threads to start processing. 2) Move the is alive and join out of the launch loop. 3) start a new loop for joining the threads. 4) before and after the join sentence, put a new doevents.
Hopefully this will 'unfreeze' (almost a little bit) your application.
and your question is how to reduce the number of parameters of your stored procedure?
A possible approach may be splitting the update in several steps all under the same transaction. Another approach is not to use a stored procedure, intead use and adhoc query from your application.
you can define a c# helper class holding all the public static variables, and having a ClassInitialize static method (mybe with parameters) to initialize all the static variable you'll need.
This methol should be called fom the New procedure of the starting form or from the static void Main from the starting program class.
If I understood well, you need to create and ad hoc query on the VB application with a variable numer of conditions depending on some rules.
I will suggest you to create a variale where clause like in the following example:
Dim strQuery as String = "SELECT * FROM table WHERE 1=1 " ' do not foret the space after
Dim strWhere as String = ""
'
' here go the rules
'
If var1 > 6 then
strWhere &= "AND F1 = " & var1 & " " ' again not forget the space
End If
If var2 > 6 then
strWhere &= "AND F2 = " & var2 & " "
End If
.
.
.
Dim Commandtext as String = strQuery & strWhere
The primary key fields should not be updated. IE: if you have an orderid = 23 is not a good practice to change it to 24 in the table orders and expect that all the related records on the processes tables will change automatically to the new key value.
Anyway, you can do it. In order to do so, all the relations (all the involved relations) between tables must be defined to update the related records in the child tables on the relations screen.
Are you sure that the internal format of the dbf file is dBASE IV? There are many formats to manage depending on the utility used to create the dbf file(dBase, Clipper, etc.)
Did you already tryed to import in an access database to verify if the format is valid?
Just some hints: 1) Compare the creation date of the executable file to the current one. 2) Create an entry in the rgistry with he installation date an chage the permission to this key to r3ead only. 3) Use a property setting in your application to be filled if empty with the current date, and another with a number of times being used. At each start, verify the date and decrease the number of remainig trys to execue. 4) Create a hidden system file in the user roaming with a name starting and ending with $ holding an encrypted value corresponding to the first usage date.
When the user click on the button to search you must: 1) Open a connection to the database, if not already open. (you already written some piece of code on that) 2) Create a SELECT command to search the free dates. That will depend on your database design, if you already have one. 3) fill a datatable with the answers from the slect command usind a data adapter 4) bind the datatable to a grid or list view to show the results.
As AppExamSchedule is autoincrement, you should create a transaction that, first inserts the values in the AppExamSchedule, then selects the highest Id in this table and uses the returned value to insert in the AppInfo table before commiting the transaction.
Please, can you clarify what do you mean with 'repeated records'? a) Allways show the same records at every refresh of the datagrid b) All the rows shown have the same values c) At every refresh, the data grid increases the number of rows, and the content of the new rows is exactly the same of the old rows
If you use a dataset, the data adapter will fill it with the data according to the select.
If the select references a query in the server, the server executes the query and returns the result to the datase.
Instead, if you fill the dataset with all the data from the table, and then apply a view to filter the data, you are wasting memory and bandwith.
Lets do some examples. Imagine you have a nice table of 16GB of data with an structure of a recordId, recordDate, recordAmount and recordQuantity. Then you need to retireve only the rows having the highest quantity (a priori you don't know wich one is/are)
If you fill a datatable with 16Gb of data ... well you know what will happen to your application.
Instead, you can fill the table using 2 techniques to obtain the desired result: + Create a query in the server that always returns the rows having the highest quantity [SELECT * FROM MyLargeTable WHERE recordQuantity = MAX(recordQauntity)] and use a SELECT * FROM MyServerQuery for the dataadapter to fill your datatable or + Create an adhoc query like SELECT * FROM MyLargeTable WHERE recordQuantity = MAX(recordQauntity) for the data adapter.
While the first solution is partially known by the server, already compiled, permissions tested and the execution plan is loaded the first time you execute it when you send the adhoc query for SELECT * FROm MyServerQuery, the second one will …
Just because your array being added to the arraylist is the same for each instance.
If you do not create a new array inside the for each loop, the array memory address is always the same (never changed), so, even added several times to the array list, internally the array list only contains the addres of the unique array being added (n times). A change to any of the items in the array list will change all.
You need to create a new array to hold the data, then fill it, then add to the array list, and start over for the next instance.
