I have a combobox that is bound to a dataset. The dataset has 3 columns of data. at any given time there could NOT be any data in the dataset.
When someone selects an item from the box I want to store data from 2 of the columns of the row they selected.I do the 'store' in the selectedindexchanged event.
so currently I am assigning each column/row value to a property from a datarowview i get from combobox.selecteditem.
But I am getting NullReference exceptions all over the place when there is not data.So i have to wrap it all in a try catch and assign nothing to the properties when the Null exception fires.
I want to also validate that there is a selection made. There must be a selection made if there is no data in the DS fill it.I do this in the combobox validate event.
It just seems like there is a better way to check for no data coming from the combobox.
I wish there was a way to do some sort of .count on the datarowview you get back from the combobox.selecteditem but anything i have found also gives a null ref exception if used.
Also what is used to programmaticly change the selected item?
I have a combobox that is bound to a dataset.The dataset has 3 columns of data.at any given time there could NOT be any data in the dataset.When someone selects an item from the box I want to store data from 2 of the columns of the row they selected.I do the 'store' in the selectedindexchanged event.so currently I am assigning each column/row value to a property from a datarowview i get from combobox.selecteditem.
But I am getting NullReference exceptions all over the place when there is not data.So i have to wrap it all in a try catch and assign nothing to the properties when the Null exception fires.I want to also validate that there is a selection made. There must be a selection made if there is no data in the DS fill it.I do this in the combobox validate event.It just seems like there is a better way to check for no data coming from the combobox.I wish there was a way to do some sort of .count on the datarowview you get back from the combobox.selecteditem but anything i have found also gives a null ref exception if used.Also what is used to programmaticly change the selected item?.selecteditem.selectedtext.selectedindex.selectedvalue?
Am I just being blind or does this If statement genuinely not do what it's meant to.[code]This displays the message box even though textSample is one of the letters. In my eyes that If statement should see that textSample is one of those letters and skip it, whereas if it was Z it would "Not" be equal to any of those and would therefore show the message box.
I'm using Visual Studio 2005, and I have a datagrid connected to a table from an Access database.
I added 4 textboxes so the user can type search filters to search within the table and a "search" button.
Then, I created a query using the "add query" tool on the datagrid. I wrote it like: select field1, field2, field3, field4, field5, field6 from table where field1=? and field2 like "%"+?+"%" and field3 like "%"+?+"%" and field4 like "%"+?+"%"
Both field5 and field6 aren't search criterias, so I didn't add them to the query. Once the query was created, I replaced the parameters inside the procedure with my textbox1.text, textbox2.text, textbox3.text, textbox4.text and then cut and pasted the whole thing inside my SEARCH button click event, so the query is executed when the user clicks on the button.
Now the problem is: when I search using the first field it goes ok, but when I try to search by any of the other fields it returns zero results, even though I double-checked I had written the words correctly. I don't know why it does this. I already tried deleting the datagrid and creating it again.[code]...
I'm trying to get my head around this issue, on a few of my functions i get a warning " 'functionDealWithHiddenFields' doesn't return a value on all code paths. A null reference exception could occur at run time when the result is used."Example function:
vb.net Function functionDealWithHiddenFields(ByVal HTML As String, ByVal numHiddenFields As Integer, ByVal X As Integer)
My system has Japanese regional settings. I have used this as default encoding in my code. But Encoding.GetString() method doesn't return proper length because of DBCS.[code]
I have myself a problem here. I created myself 2 classes like the ones below:
1) Vehicles 2) SportsCars
I then created some "Properties" like the ones below:[code]I want to get the price of a selected car, but when i try to build i get the following error: Property 'Cars' doesn't return a value on all code paths. A null reference exception could occur at run time when the result is used.
What does this warning mean and how can i get it to go away.? Warning1Function 'ipAddr' doesn't return a value on all code paths. A null reference exception could occur at run time when the result is used.C:Documents and SettingsHP_AdministratorDesktopMoney Manager in MysqlMoney Manager V1connection.vb385Money Manager V1
I have a function to recursively search through windows (and their child windows) to find specific ones, it works exactly as expected, however it causes "function doesn't return a value on all paths" warning. This is the only warning in my entire program, and although it might be silly, I'm interested in knowing if there is a way to stop this error from occurring, but still allowing the function to work properly.[code]
i get a warning " 'functionDealWithHiddenFields' doesn't return a value on all code paths. A null reference exception could occur at run time when the result is used."
Example function:
vb.net Function functionDealWithHiddenFields(ByVal HTML As String, ByVal numHiddenFields As Integer, ByVal X As Integer) Try
[code]....
The functions still work correctly (as far as i can tell) what would i need to do to the above function to remedy that warning?
I have this VB crypter I am trying to build, but I am getting 2 warnings. I Would like some help if someone has the time. Please PM me and ill send you the crypt.Warning 1 Function 'ReadEOFData' doesn't return a value on all code paths. A null reference exception could occur at run time when the result is used. I:Usersn oahDesktopI am CrypterI am CrypterForm1.vb 189 13 I am Crypter
Warning 2 Variable 'Buf' is used before it has been assigned a value. A null reference exception could result at runtime. I:Users oahDesktopI am CrypterI am CrypterForm1.vb 203 19 I am Crypter
I have written the following stored procedure: ALTER PROCEDURE ProcGet Add the parameters for the stored procedure here @id as int output, @name as varchar(50) output ASBEGIN -- SET NOCOUNT ON added to prevent extra result sets from -- interfering with SELECT statements. SET NOCOUNT ON;
Background: My application is used to execute tests using Selenium RC servers, and occasionally I'm running into a problem when my call to a Selenium command doesn't return the response from the RC server - it then ends up blocking the thread that is executing the test.
i have a dataset that i am viewing in detail view i can enter a new record and save it fine but the auto ID field enters as (-1) after i save it does not automatically change the (-1) to a number so i need to clear the dataset then refill it to give it a genuine number to prevent concurrency violations. my problem is after i refill the dataset it returns to the first record in the dataset not the last entered record, how do i get it to return to the last record.
I am trying to call a SELECT query (with parameters) in Access from VB.Net 2008. I am able to call queries without parameters using the code below. The problems are (1) how to apply the parameters to procName and (2) how to get a dataset returned. I have looked around the net for hours and have found some examples. However, they are all for ms access action (update, delete, etc) queries using ExecuteNonQuery which does not return a dataset.
I am using a Strongly Typed Dataset as DAL. I want to return a single column from my table for that i wrote the code as
SELECT DISTINCT Floor FROM Room WHERE (Building = @Building)
But when i previewed the data, it shows me all the columns of the table with Null Value and the column with primary key has -1 value. This condition raise an Exception when i link this query to a ComboBox ..
im trying to get mac adddress from this code but i get eerror on END FUNCTION line it says this "function 'getRemoteMac' doesn't return a value on all code paths. A null reference exception could occur at run time when the result is used." what am i missing here?
i have a datatable named booking_table and i filled it with column names and values
Dim booking_table As New DataTable booking_table.Columns.Add( "Time", GetType(String))
[code]....
than the rowindex(0) I want it to start with "8:00" than for example the rowindex(47) should end with "19:00" extra info: every our is parted in four sections of 15 min for example 8:15, 8:30 ,8:45?i want to select the starttime by date.bind to DGV?
i have a textbox1=Year and a textbox2=Month and a datagridview and as datasource access i want to know the code if i search for a year in databinding and how to look for a month of the focused year?
I have 2 listboxes, listbox1 holds File names, listbox2 holds fullpath of the files(listbox2 is hidden just to keep things looking tidy).
What i want to do is (using multiselection) is select files in listbox1 and have listbox2 have the same files(indexes) selected as well.
i am rather new to this but i have tried several ways but listbox2 only selects the first selected file from listbox1.I am using vs2010 visual basic & wpf?