I have this code:
Code:
Private Sub CheckBox1_CheckedChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles CheckBox1.CheckedChanged
If CheckState.Checked Then
AmxModXInstallDir.Enabled = False
Button1.Enabled = False
[code]....
When i check the box, it enables all controls, if i uncheck it, nothing happens.
I understand that Checked is a boolean, which is not the case of CheckState.I understand that CheckState also have a undeterminate possible value.But I don't understand why we have them both. I think that CheckState would be sufficient. What is the need for Checked ?
View 10 RepliesWhat are the pros and cons of using the checkboxes checked property vs the CheckState property for databinding?
View 1 RepliesI want to create a solid checkbox that is checked by default, and is not clickable. If you click it, nothing will happen . how to do this?
View 2 Repliesfrom the code below I am trying to find out if checkBox1 is Checked or Unchecked. and then I want my settings to remember if it is checked or unchecked. so when the form is loaded I want my settings to load the last action.... ie checked or unchecked.
so if a user check's the checkbox1 then the message will not show, But if it is unchecked the the messageBox will be shown
Private Sub CheckBox1_CheckedChanged(sender As System.Object, e As System.EventArgs) Handles CheckBox1.CheckedChanged
If CheckBox1.Checked = True Then
[Code]....
The check box list has an event called "ItemChecked" or something, which triggers when an item is about to change its checked status.
So, it is before the check occurs.I couldn't find an event that occurs after the item has changed.. I want to execute some code only when an item is checked or unchecked.
In Vb.net 2005 how can i trap the checked/unchecked state of a datetimepicker through an event. I'm trying to execute two different methods based on the checked/unchecked state of a datetimepicker when the user clicks the datetimepicker. When the user checks the dtPicker Method A is executed, when the user unchecks it Method B is executed. How can i trap it.
View 1 RepliesSo I'm trying to figure out how to correctly override GetHashCode() in VB for a large number of custom objects. A bit of searching leads me to this wonderful answer.Except there's one problem: VB lacks both the checked and unchecked keyword in .NET 4.0. As far as I can tell, anyways. So using Jon Skeet's implementation, I tried creating such an override on a rather simple class that has three main members: Name As String, Value As Int32, and [Type] As System.Type. Thus I come up with:
Public Overrides Function GetHashCode() As Int32
Dim hash As Int32 = 17
[code]....
Problem: Int32 is too small for even a simple object such as this. The particular instance I tested has "Name" as a simple 5-character string, and that hash alone was close enough to Int32's upper limit, that when it tried to calc the second field of the hash (Value), it overflowed. Because I can't find a VB equivalent for granular checked/unchecked support, I can't work around this.
I also do not want to remove Integer overflow checks across the entire project. This thing is maybe....40% complete (I made that up, TBH), and I have a lot more code to write, so I need these overflow checks in place for quite some time.
What would be the "safe" version of Jon's GetHashCode version for VB and Int32? Or, does .NET 4.0 have checked/unchecked in it somewhere that I'm not finding very easily on MSDN?
EDIT:Per the linked SO question, one of the unloved answers at the very bottom provided a quasi-solution. I say quasi because it feels like it's....cheating. Beggars can't be choosers, though, right?
Translated from from C# into a more readable VB and aligned to the object described above (Name, Value, Type), we get:
Public Overrides Function GetHashCode() As Int32
Return New With { _
Key .A = _Name, _
[code]....
This triggers the compiler apparently to "cheat" by generating an anonymous type, which it then compiles outside of the project namespace, presumably with integer overflow checks disabled, and allows the math to take place and simply wrap around when it overflows. It also seems to involve box opcodes, which I know to be performance hits. No unboxing, though.
But this raises an interesting question. Countless times, I've seen it stated here and elsewhere that both VB and C# generate the same IL code. This is clearly not the case 100% of the time...Like the use of C#'s unchecked keyword simply causes a different opcode to get emitted. So why do I continue to see the assumption that both produce the exact same IL keep getting repeated? </rhetorical-question>
Anyways, I'd rather find a solution that can be implemented within each object module. Having to create Anonymous Types for every single one of my objects is going to look messy from an ILDASM perspective. I'm not kidding when I say I have a lot of classes implemented in my project.My final implementation, which fits the constraints of GetHashCode, while still being fast and unique enough for VB is below, derived from the "Rotating Hash" example on this page:
'// The only sane way to do hashing in VB.NET because it lacks the
'// checked/unchecked keywords that C# has.
Public Const HASH_PRIME1 As Int32 = 4
[code]....
I also think the "Shift-Add-XOR" hash may also apply, but I haven't tested it.
I have a checkbox list which is filled with entries from my database on page load. I need to update an entry in my database when a item is checked and when an item is unchecked. Right now I am doing the following:
<asp:CheckBoxList id="check1" AutoPostBack="True" TextAlign="Right" OnSelectedIndexChanged="Check" runat="server">
</asp:CheckBoxList>
And the function:
Sub Check(ByVal sender As Object, ByVal e As EventArgs)
Dim sql As String
If check1.SelectedItem.Selected = True Then[code]....
The error is: "Object reference not set to an instance of an object." Is there a better way to check if a list item is checked or unchecked?
I have a Main form, called Main.vb, that is a Parent Form. I have another form called Notes.vb. Inside Main.vb I have a toolstrip with a button on it called Notes. I'm wanting to change the checked status of the Button to either True when the Notes.vb window is open inside the parent or to false when it is close. Is this possible?
View 6 RepliesHow can i trap the checked/unchecked state of a datetimepicker through an event. I'm trying to execute two different methods based on the checked/unchecked state of a datetimepicker when the user clicks the datetimepicker. When the user checks the dtPicker Method A is executed, when the user unchecks it Method B is executed. How can i trap it.
View 6 RepliesHow to count the total no. of asp.net checkboxes, checkboxes checked, no. of checkboxes remain unchecked in webform using vb.net ?I m using Visual studio 2008 with vb as a language ..I my webform i have 10 checkboxes...i wanna count total no. of checkboxes in webform in textboxes1 total no. of checkboxes checked in webform in textbox2 total no. of checkboxes remain unchecked in webform in textbox3?
View 2 RepliesWith this project i had to link a MySQL database and then let it add every item in the table as a new checkboxitem, and that is working perfect, but now i need to get the check state of each of these items with an if statement because these need to act like a filter.i tried a couple of times but i just cant get the result i need.
[code]...
Ive got a CheckedListBox with 20 rows in it, each with checkbox's which are checked or not-checked. What I want to do is to check each checkbox, row by row to see if it is checked, and then to store this is a listofintegers (1 if its checked, and 0 if its not).So the output listofintegers should be something like "01011000010100010011".
Dim sw As New StreamWriter("N:
umberstring.txt")
Dim sWrite As String = Nothing
[code].....
Okay I am now using a CheckedListBox and I was wondering if there is a way to save the checkstate of the items? Its very easy with checkboxes but I have not found out how to do it with this.
View 5 RepliesI am attempting to create a dynamically built form, where by the user adds names to a listbox using a setup screen, the listbox names are written to an .ini file, then the main app:
[Code]...
im trying to get value of a constructed checkbox.checkstate value.[code]
View 3 RepliesCheckedDatetimePicker col inside DGV How can I get set checkState? I made an editControl and inserted a checkDateTimePicker column. I need to checkState of the control in currentRow. I have searched high and low..
View 1 RepliesI'm trying to read the checkbox checkstate from the listview.Here is what i got:
[code]...
The code reads ever column text perfectly but does not read the checkstate of the checkbox.Because the checkbox has no text to it.I was thinking of giving each checkbox a tag and on the click event change tag from True to False depending on checkstate. Is that a good idea or is there a faster way around this?
im trying to read 20 checkbox.checkstate into an array
[Code]....
Insert checkbox checked value when checked to textbox as comma seperated string in vb.net or javascript
suppose i have 3 checkboxes and and 1 textboxes in my webpage.aspx
when i checked checkbox1 and checkbox2 then in textbox it will appear as 1,2 only on checkboxes checked event ...
and i want its revert also :
if i set textbox de
my form contains a checked list box [data coming from the database] a combo box [bind to a database table product] and a listview [was previously a listbox]
[Code]...
project im working on for my course,the idea is a photo printing machine that loads up 4 images if usb stick is checked and a different 4 if memory card is checked. and then whatever image is selected appears in the big picturebox on the left [URL] i have 2 print size options set as radiobuttons, radiobutton 1 = 6x4, which costs 25cent per photo, radiobutton 2 = 8x10, and is 50cent per photo.i also have a textbox which will display the number of copies to be printed So here's my dilemma, when the print button is selected alongside one of the radiobuttons i want it to display a message saying something like this "you have selected (whatever the amount of copies)of this photo sized 6x4, or 8x10 depending on which radiobutton is selected, and i want it to display the total cost which is the number of copies multiplied by the rate for the print size selected, then an option saying "Do you wish to proceed" Yes or No.
I did something similar to this in class earlier in the year but cant remember it, it was an airline booking program with 3 types of payment cash, visa or mastercard,upon booking a message popped up saying there is a certain percentage discount for using visa or mastercard
I have a checkbox on my form chkActive, I want to deal with it in 3 cases. [Code] I don't have a problem with building the query, my problem is with clicking on the checkbox by clicking on the checkbox by mouse, I can only get Checked and Unchecked, I tried to use the right mouse button click, it did not fired (or I did not test deep enough) I know I can put a button to change the checkbox value to Indeterminate but that will be ugly. I can replace checkbox with combo, which is what i am thinking of doing but I just wonder: Cannot I set the checkbox state to Indeterminate by mouse any how?
View 2 RepliesI'm trying to reset a form after a game has been played. I used checkboxes to indicate when the user picked a particular line item to update and then flagged the checkbox as checked and disabled.Once all the checkboxes have been checked, the game is over and I want to show a dialog (msgbox) that will allow the user to start a new game or exit the app. To reset the form, I was changing all the checkstates back to unchecked (along with resetting other variables), but the checkchanged events are being triggered and I end up in a loop.Is there a way to change the checkstate without triggering the event?[code]....
View 2 Repliesim making dynamic sql statement rmode is a radio button and tmode is a combo box
[Code]...
I've got a checked listbox on my form which saves the checked items to a spot in my database on the .ItemCheck event.But there's a problem, when I begin checking items, I check the box and click off it, but it doesn't save. (This is if I've only chosen one item)
If I choose two or more items it will save, but unchecking them takes a lot of clicking around to figure it out.Is there a better event that I can use? I've tried the SelectedIndexChanged and that has the same result, there's a lot of clicking around in the checkboxes to end up with the desired selected items, and it does not allow a single item.
In a listview with check boxes, there are two fields being loaded, ID and Lastname. With this information I want to get the ID of the person whose box is checked with this sub:
[Code]....
I trying to get what I think should be a simple thing. I have a checked treeview. I need to get the text of each checked node into a string. For the life of me I can't get it. I am trying to loop thru all the nodes and see if they are checked but I keep getting a "object reference not set to an instance of an object" but I don't know why.
Dim value As String
Dim node As TreeNode
Dim i As Long
[Code]....
I have a project where I want to have checked arithmetic by default, except for one performance sensitive spot. Unfortunately, VB.Net doesn't have an 'unchecked' block.Ideally the framework would have some sort of integer type with explicitly unchecked arithmetic, but I didn't find anything like that. I did find that expression trees have binary expressions for unchecked operations, but the delegate overhead cancels out the unchecked advantage (and then some).
Currently I'm converting the inputs to UInt64/Int64 before doing the arithmetic, then converting back (with a bitwise And to ensure in-range). It's about 50% slower than unchecked arithmetic (according to profiling).
Moving the arithmetic-sensitive part to a project with unchecked arithmetic might work, but it seems like overkill to give it an assembly all to itself.
