I want to be able to have the user type in a function, say ,x^2 + 1, and have the computer store this such that it can be recalled and plug in a given value for x. For example, say they type in x+4, the program will then (in a bunch of different text boxes) return the value of x+4 when x = 1, x = 2, and so on up to x = 10. But how can I get it so that it will store x+4, be able to recall it and replace x with it's given value
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I am creating a gridview and need to gather the data from various functions that return a type of IEnumerable. I've created gridviews using a dataset as a datasource, but how does one use multiple data sources(of IEnumerable) to populate one gridview? Like how do you combine all that into one dataset?
View 1 RepliesI am currently using double data types. The problem I am encountering is that sometimes the user will have to input a value of 0 in the required text box and this creates an error. My question is what data type will allow the user to input 0 and allow the mathematical functions to work properly. Decimals maybe?
View 8 RepliesFor each column in data table i want to add parameter with same data type as column data type. But looks it's not that simple.
Dim cmd As New SqlCommand
Dim dType As New System.Data.SqlDbType
For Each cl As DataColumn In DataTable1.Columns
[CODE]...
How can I do this?
I usually always use enummerations as a pass ID of some type with a calculated value using the n^2 notation to calculate the return values. It's easy to derive with squareroots what values are derived from a sum; but most of the time I use the Identifier String to denote a combo box drop down list view. I think this is fairly routine for most developers; since in all my coding or rework I have seen it used commonly by other developers also.
Anyway, I wanted to do some sort of comparisson array of strings to fill the combobox using the *.Items.AddRange() function and it requires an array pass (this typically shrinks the code down considerably) and if you want to mix and match arrays in segments it's easier. So here is the code; for doing so I am assuming that other developers use an "AddToArray" type function like me; if not you have to write the function or just replace the code with the actual adding to array.
''' <summary>
''' Convert an enummeration to an array.
''' </summary>
''' <param name="ConvertTo">Convert to return type.</param>
[CODE]...
What I am trying to do is have a class where the functions of the same name are both instance functions and shared functions.
Public Shared Function Get...(byval xx as xx)
and
Public Function Get...
The Public Function uses a Property xx created in the constructor, whereas the Shared Function has the parameters (byval xx as xx).
Is there any alternative to VB's CBool keyword in C#?
What about all the other functions?
CBool will turn to a Boolean any valid boolean: 0, "False", null etc.
So I'm trying to import a function from a library I'm developing. I have "libraryD.dll" built for debugging and "library.dll" for release. Unfortunately, that means that I have to do this:
[Code]...
Now this would be fine but for ALL 40 functions this would make things very ugly to look at (and a tad bit unfriendly).I would like to do something more like this:
[Code]...
Is there ANY way to do this in VB?
I need to create a function which have either 1 parameter with a string as data type or 2 parameters with double as data type.Something like the substring method.
View 2 RepliesI'v designed a ms access database table with one field having Datetime datatype. I can Insert data into it from vb.net front end by trns_dt DateTime.Now.DateBut when I fetch records from the tableand assign the dataset datasource as da, it shows datatype mismatch error.
daleDbDataAdapter("SelectDaily_Transactiondtp_from_dt.value dtp_To.value con)
dsDataSet
[code].....
Planning on migrating from 1.1 to 2.0 framework.After doing the automatic vs 2005 migration, it did highlighted lot of lines: due to unused variables and functions with no return type..Is there a tool which can fix those unused variables plus function with no return types.
View 2 RepliesI have a program that calculates commission, but if the commission is nothing then I do not want it to show a zero commission. I want a message box to show a message that there is no commission earned.
View 1 RepliesMy colleague gave me a DLL that manage all database business. I wanted to invoke a function that uses Stored Procedure and return the search result. In the function receive a parameter type in ystem.Data.IDataParameter[]. Below is my codes.
[Code]...
I have a function (on vb.net) to get a data from a XMLWebService:
[Code]...
I added this lines in the form load of DataGridPrinter by Merrion in the codebank..[code]Unable to cast object of type 'System.Data.DataViewManager' to type 'System.Data.DataTable'.
View 2 Repliesevery time i run this code i get the same error
Unable to cast object of type 'System.Data.DataTable' to type 'System.Data.DataView'.
the code is
Dim plmExcelCon As New System.Data.OleDb.OleDbConnection
Dim cmdLoadExcel As System.Data.OleDb.OleDbDataAdapter
Dim PrmPathExcelFile As String
[Code]......
[code] "The conversion of a char data type to a datetime data type resulted in an out-of-range datetime value.The statement has been terminated." [code]
View 6 RepliesI have one question. i have seen some codes like:
Req = CType(System.Net.HttpWebRequest.Create("url"), Net.HttpWebRequest)
Is it really necessary to cast the same type, or is there a difference when its not casted.
I would like to have custom methods to pass data between function, or to keep it in memory throughout the program.
Example:
Private function info()
Addr1 = addr1.text
Addr2 = addr2.text
City = city.text
[code]....
Could I run this function towards the beginning of the program and use it throughout until the form is disposed? I can't seem to get the information to stick once I get out of the function, I will need to use the same information multiple times throughout the application so I figured if I could make a function to keep the info rather than declaring the 5 lines in every option but anytime I call the method, it fills it correctly then when I get back to the main function the info goes back to 'nothing'. is it possible to pass data around between functions like you could in Java?
I have a number of controls (Device1, Device2, etc.) that all inherit from BaseDeviceControl. In the DragEnter event handler I am trying to test for the correct type by using the BaseDevvceControl like this....
[Code]....
I am pulling data from a local MSSQL database using a stored procedure, then send the data to a web service. Every part of the component works well except for a pesky problem will a DBNull being returned from the DataRow field, when I know that the field is not null and has valid data. The database and associated INSERT statements that add to this field are designed to not allow NULL entries. When I debug break the program on or right before the line that throws the error I see that the field has valid data for the current row.If I add a null check to the code (as below) the operation continues as normal:
Dim dataResultsTable = Me.myViewTableAdapter.GetData(int)
For Each myDataRow In dataResultsTable.Rows
If worker.CancellationPending Then
[code]....
Why is the read operation returning DBNull instead of the data in the database?
EDIT: Just to be clear, the operation does return the proper data, but the data is not being saved into the variable.
<ItemsControl DockPanel.Dock="Top" ItemsSource="{Binding Path={x:Static vmc:clsPersonViewModel.ChildrenPath}, Mode=OneWay}">
<ItemsControl.ItemTemplate>
[Code].....
In the code above, if there are no children (the ChildrenPath property returns NULL), nothing is rendered in the view. In the code below, when ChildrenDataSetPath is NULL the XamDataGrid still gets rendered. How do I achieve the same for a single object (as opposed to a collection) as the datacontext?
<DataTemplate DataType="{x:Type vmb:clsPersonViewModel}">
<igDP:XamDataGrid DataSource="{Binding Path={x:Static vmb:clsPersonViewModel.ChildrenDataSetPath}}">
[Code].....
I have only 2 sets of "fixed" numbers used, that I need to be able to toggle between. Particularly, for array sizes/for loops. Is it best to use "Collections" in VB.NET to accomplish this?
View 5 RepliesI am trying to send data and arrays using System.Object and System.Event. Lets say I have 4 pieces of data: date, y(1),y(2),y(3).
sub main(...)
Dim date,y(1),y(2),y(3) as integer
Dim obj as System.Object
Dim args as System.Eventargs
How do I organize obj with all the integer data above so I can send it to main2.
main2(obj,args)
end sub
Sub main2(obj as System.Object,args as System.Eventargs)
End Sub
And how do I apply this to (ByVal sender as System.Object, ByVal e as System.EventArgs). I am using VB.net 2005.
I freely admit that I tend to avoid using API calls as much as possible I wish to use this API call
[Code]...
1) Is it possible to access the Excel mathematical functions without actually opening Excel?
I was thinking of through a DLL WinAPI call or maybe a delegate function or smaller program?
2) Does anyone know of a MS link or area that gives instruction on "how to" use every function of every Windows DLL at all?
Or for all those that Microsoft have chosen to document online at least.
I would like an overview of System.EventArgs. I have an understanding of System.Object where I can pass data between subroutines and functions using Public Classes. I am curious what EventArgs do?
View 3 RepliesSo im using the inno installer to set up my project and i found a nice script that will check and download 3.5 framework, but can't get it to work for 4.0 so my question is would i be able to compile my project in 3.5 and everything still work correctly?
My program just uses basic math functions and display the data in datagridviews. It uses webbrowser and other toolbox options. It doesn't use the registry and only creates one txt file.
I have an InvalidCastException Error in my program. The program is that i try to insert an employee record into a database table after getting the details from a form. I've used Money data type is SQL Server for salary and SqlTypes.SqlDecimal data type in employee template class. i've used a stored procedure to pass the values and i add the basic value by passing a parameter by the method
Dim prm8 As SqlParameter = com.Parameters.Add("@basic", SqlDbType.Money)
prm8.Direction = ParameterDirection.Input
prm8.Value = emp.Bsc
I've used the money datatype itself even in the stored procedure variable.I get the following error.
failed to convert parameter value from sql decimal to decimal
Even if i use
prm8.Value = Convert.ToDecimal(emp.Bsc)
I get an error Unable to cast object of type 'System.Data.SqlTypes.SqlDecimal' to type 'System.IConvertible'.
I am getting this error when I am tring to load string type to data table)
Using connection As New SqlConnection("connectionstring;")
connection.Open()
Using Command As New SqlCommand("SELECT ClientId,forename,surname from t_clientdetails
[code].....
