I'm working on a small project, and ran into an issue. I'm creating new picture boxes on a form to represent a control. My question is how would I code a click event for an object that isn't on the forum initially? Also, how can I keep track of which object is assigned to which data in an array? (IE picturebox 0 is array(0) of data)
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Currently, whenever I pass a string to the db, if that string is empty, then i set that object to NULL by doing the following:
IIf(DescriptionTxt.Text.length > 0, DescriptionTxt.Text, DBNull.Value)
I was thinking about writing a function to reduce the length of this code, and make it more consistent.However, I was wondering, is there already a way of doing this in .NET 3.5?
How Do I Track An Object With A Webcam?
View 2 Replieshow to track an object such as your eyes or a red ball with VB.NET using a webcam or some other video device. I know I have seen a guide to do this, but I can no longer find it.
View 1 RepliesI can define a NEW sub that runs when an object is instantiated. What is the correct sub to call when it is disposed? I would think a method named dispose, but I seem to remember somewhere that there is a better choice than dispose.
Why do I care? I want to be able to track when a given object is released.
With a form, I can use formClosing, but what about a simple class definition?
how I would know what to search for to have found it without bugging any of you? everything I tried resulted in way too many hits that had nothing to do with VB or what I wanted to achieve.
In my example, i use a class array to which I assign values looping through textboxes in my form. Using the button Store (btnStore) the values are perfectly assigned to the array (i use an msgbox to check).The problem is that when i created another button (btnTest) to test if these values can be read outside the btnstore code, I get an error (NullReferenceException unhandled) which informs me to use the new keyword (cannot be used with arrays).I suppose the same applies when trying to access the array from another form. The question is how can i assign the values to the array "forever" and be accessed from "everywhere" in my program ?(tried public, friend, redim preserve the array with no luck).
[Code]...
I am writing a class library to interact with a domain Active Directory. In my object model, I have the following:
Domain;
Organizational Unit;
Group;
User.
In my Domain object, I have an Entries property and an Add() method.
public class Domain {
// The ReadOnlyDictionary<TKey, TValue> is a custom wrapper over an IDictionary.
public ReadOnlyDictionary<string, IDirectoryEntry> Entries { get; }
public void Add(IDirectoryEntry entry) {
Entries.Add(entry.Name, entry);
[Code] .....
For your information, I implemented the INotifyPropertyChanged interface to ease my life, but I don't seem to find a way to make it work the way I want. Perhaps am I not doing things right somehow, as for the location of different methods, I don't know. How can I make my Domain aware of a change that occured within one of its Entries, so that the TKey value is also changed? That is wanted because one could possibly add an entry, change its name meanwhile adding a new entry with the "old" name of the actual within entry, and cause a conflict, etc. In the end, causing the test to fail. But I'd like to make it pass like it actually is. Is there another better approach or workaround?
I have short code like this :
Dim arr1 As New List(Of Integer)
For i As Integer = 1 To 100
arr1.Add(i)
[Code]....
My problem is : after RemoveAt command is value of array 2 is change this is true, but why it effect to array 1 , i don't want array 1 value change
I am not sure how to phrase my question properly but I want to achieve something like this.
I have a class named Products public class Products
private ID as Integer
private Name as String
Public Property ProductID()
Get
Return ID
[Code]...
When I do the same, I am getting an error "Object Reference Not Set to an Instance of an Object.
I want to create an in-memory object in VB.Net with multiple columns. What I am trying to do is create an index of some data. It will look like:
Row 1: 23 1
Row 2: 5 1
Row 3: 3 38
...
I know I can use a rectangular array to do this, but I want to be able to use indexOf opearations on this object.
I'm having a bit of trouble developing my login page! Currently i have 2 text boxes which a user can input a username and password. My form should then check whether this data relates to the data in the database and either grant or deny access.The error i'm receiving occurs at the line "If theDataReader.HasRows Then"It says 'The data reader has been used before it is assigned a value"
Here is my code:
Imports
System.Data.SqlClient
Partial
[code]....
I have made a application that detects already saved hotkeys and data assigned to them, so now whenever I press the hotkey to send the assigned data to active window it does sends the data to active but it won't stop sending data...I am calling my function that reads data from the database in timer device and the function that detects the hotkey...
Here is my code
Private Sub Hot_Checker_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Hot_Checker.Tick
gKey.CheckBox()
'is the object that calls the function to check the pressed hotkey
keyTemp = gKey.getHkey()
[Code] .....
trying to find the main error that is causing this to happen, after pressing the hotkey my app won't stop sending the data to the active window. My app should wait for the next hotkey press rather than sending data.
I have data(one byte) that want to write on the Last Track of CD (the end of a cd ,where that is not able to write any more data on it)and read that. I dont want change CDFile system data
View 1 RepliesI have created a little program that helps me keep track of tons of data by inserting it into sql. I created 5 forms and all 5 can insert data at the same time, but mostly just 1 of these is working continuously. I have noticed that the program will run, then at random times it will stop responding (can't minimize/click on anything/data entry stops), and the only way to stop is to kill the task. I can't even click in the debugger to set a break point when it happens, and setting breakpoints before debugging is useless as the program could run 2 hours and stop, or 10 minutes and stop. 5 forms, they open different excel files, insert data into sql, and repeat.
View 5 RepliesI want to create a program that will keep track of the amount of (network/internet download) data that has been received, but I have know idea how to go about doing it.Where would be a good place to start with this type of development? Or could some one give me example code that will get me started.
View 1 RepliesI am using vb.net with phpMyAdmin MySql database. While running the piece of code below, the program hangs in the for loop before the variables are assigned values from the data table(dt)...
'Check for appraisal period-----------------------------------------------------------------------
Dim sqlCheckDate As String = "SELECT * FROM tblappraisalsetting where appSetID=(select max(appSetID) from tblappraisalsetting);"
[CODE]................
i wanted to ask how to make picturebox1 ,to which functions are already assigned, perform the same function as picturebox2 ,to which no functions are assigned.For example:I have already made picturebox1 and have assigned it alot of function like when play button is pressed then picturebox1.visible = true and when we press pause button picturebox1.visible = false. So now i decided to make a theme and have to remove the picturebox1 and want to allow the picturebox2 to havefunction of picturebox1.But when i disable the theme the function of picturebox1 should go back to picturebox1.
View 6 RepliesHere is the structure that I have:
Friend Class StandardFormatFile
Friend fileType As String
Friend numberOfSeries As Integer
[code].....
I didn't think it fair to post a comment on Fredrik Mörk's answer in this 2 year old post, so I thought I'd just ask it as a new question instead..NB: This is not a critiscm of the answer in any way, I'm simply trying to understand this all before delving into memory management / the marshal class.
In that answer, the function GetByteArray allocates memory to each object within the given array, within a loop.Would the GetByteArray function on the aforementioned post have benefited at all from allocating memory for the total size of the provided array:
Dim arrayBufferPtr = Marshal.AllocHGlobal(Marshal.SizeOf(<arrayElement>) * <array>.Count)
I just wonder if allocating the memory, as shown in the answer, causes any kind of fragmentation? Assuming there may be fragmentation, would there be much of an impact to be concerned with? Would allocating the memory in the way I've shown force you to call IntPtr.ToInt## to obtain pointer offsets from the overall allocation pointer, and therefore force you to check the underlying architecture to ensure the correct method is used*1 or is there a better way? (ToInt32/ToInt64 depending on x86/64?)
*1 I read elsewhere that calling the wrong IntPtr.ToInt## will cause overflow exceptions. What I mean by that statement is would I use:
Dim anOffsetPtr As New IntPtr(arrayBufferPtr.ToInt## + (loopIndex * <arrayElementSize>))
I've read through a few articles on the VB.Net Marshal class and memory allocation; listed below, but if you know fo any other good articles I'm all ears![URL]..
I am creating a dll with all the functions and subroutines that I use all the time and I decided to create a function that I can pass different types of array to so the function obviously (or not) would have an array of type object. Now I no you can pass any type into an object type but when I pass an integer array into an object array I get an error.
value of type '1-dimensional array of integer' cannot be converted to '1-dimensional array of object' because 'integer' is not a reference type.
Shared Function CompareArray(ByVal FirstArray() As Object, ByVal SecondArray() As Object, Optional ByRef ErrorMessage As String = "") As Boolean
Dim IntArrayOne() As Integer = {1,2,3,4,5} Dim IntArrayTwo() As Integer = {1,2,3,5,6} Dim IsSame As Boolean = False IsSame = CompareArray(IntArrayOne(), IntArrayTwo())
I am having some trouble creating an object array of different object types. Here is what I have so far:
Public Sub New()
Dim b1 As New Book("Book Title 1", "Gold Book Publisher", 1.0, "Bob Jones", "192DJDJD212", "01/02/10")
Dim b2 As New Book("Book Title 2", "Gold Book Publisher", 1.0, "Bob Jones", "192DJDJD212", "01/02/10")
Dim b3 As New Book("Book Title 3", "Gold Book Publisher", 1.0, "Bob Jones", "192DJDJD212", "01/02/10")
[code]....
If I define the array As Book (Public publicationArray(6) As Book) or Magazine (Public publicationArray(6) As Magazine) I am able to access the properties of that class but not both. I think I need to define a type for each array instance but not sure how to do this.
I have an interface that describes an specialized list in my application...
[Code]....
Is there a way to make an interface serializable, or am I going to have to convert each of my objects into a concrete class implementing the interface, and then return that class?
what's the difference between variable array and object array?
View 7 RepliesThe last line in the code below throws the error. Is it because I haven't intialized the size of the byte array?
Public Class Form1
Private toSocket_IPP As Byte()
Public Sub New()
[code].....
I am working on a project and came to a junction. I have various data in a object array, myObj().
How can one convert Object Array to Byte Array
I dont know if i should be using Memory Stream, Buffer, etc.
I'm trying to set the format of a column in a datagridview.When I put the format statement in the on load event for the form, it has no effect. When I put it in the cellformatting event I get the "Object reference not set to an instance of an object" error. I checked the column name. What I am doing wrong?
This is the code:Private Sub MeetingTblDataGridView_CellFormatting(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellFormattingEventArgs) Handles MeetingTblDataGridView.CellFormatting
Me.MeetingTblDataGridView.Columns("Starttime").DefaultCellStyle.Format = "HH:mm:ss"
End Sub What I'm trying to do is get rid of the date part of a Date/Time field (stored in an Access database) in a datagridview column.
dp.SyntaxHighlighter.ClipboardSwf = '/dp.SyntaxHighlighter/Scripts/clipboard.swf'
dp.SyntaxHighlighter.HighlightAll('09dde30f062e451a854266e66205b1cf')
I was create Access database with Access 2003. I create VB project with Visual Studio 2005 Standard With connection wizzard I create coonect with this Access database, select all tablesI see this database inside Data sources and inside Server explorer Test connection is OK When I drag and drop table from Data sources, Wizzard don't create DataGridView, DataSourceBinding etc .. and I see popup window with mesage: Object reference not set to an instance of an object and then "game over"
View 2 RepliesThis is my code in vb.net 2010:
Structure feature_s
Public feature() As Integer
End Structure
[CODE]............
I keep on getting a error "object not set to an instance of an object" i am puzzled by this since there are no errors until i run the program. I redim the array. the build is fine. the exception is handled. and the structures and "dims are all global"
I'm trying to sort an array based on a structure but whenever I do this, it basically erases all the data in the entire array.I have verified that the array is populated correctly, it is when using array.sort that everything returns blank.
View 6 RepliesI want to reading in a excel file and extract the sCodenumber sDescription ans the sStatus and store them in a array : StatusComposeArray(5200) As MyCompose. After this I need this array for comparing outside this class. But as can you see the array is defined inside the sub: ReadingIn_ExcelFilesCompose [Code]
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