Creating A Checkbox That Can't Be Checked Or Unchecked?
Mar 3, 2012I 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?
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Asp.net - Check If A Checkbox List Item Is Checked/unchecked?
May 14, 2012I 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?
Refresh Checkbox - Getting The Checkbox Unchecked For The 2nd Address?
Jun 30, 2009I've got a form with parent-child setup. The parent displays name and other demographic info.The child displays multiple addresses, one row at a time. There can only be one primary address for a name and this is designated by a checkbox at the top of the child form.If the user wants to change the primary address to another address,then they find the other address and click on the checkbox.The form checks the other addresses and if one is found that is designated as primary,the user is warned that one already exists and prompts them to change it.
So for example, a name has 2 addresses, the 2nd being the primary address.The user wants to change the 1st address to be primary.They click on the Primary Address checkbox for the 1st address.A warning displays that there is already an address listed as primary.The user then answers the prompt to change the 1st address to the primary address.The checkbox for the 2nd address will be unchecked and the checkbox will be checked for the 1st address.My problem is getting the checkbox unchecked for the 2nd address.If I close the form and reopen, then the checkbox is unchecked.How do I refresh the checkbox for the 2nd address?Here is the code I'm using to find if an address has already been marked as primary:[code]......
Checkstate.Checked Don't Work When Unchecked?
May 28, 2009I 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.
Find Out If CheckBox1 Is Checked Or Unchecked?
Apr 28, 2011from 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]....
Execute Some Code Only When An Item Is Checked Or Unchecked?
Jan 8, 2011The 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.
Trap Checked / Unchecked State Of A Datetimepicker Through An Event?
Mar 14, 2009In 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 Replies.net - Overriding GetHashCode In VB Without Checked/unchecked Keyword Support?
Jan 11, 2011So 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.
Button In Toolstrip Checked / Unchecked Depending On Window State
Jun 3, 2011I 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 RepliesForms :: Trap The Checked/unchecked State Of A Datetimepicker Through An Event?
Mar 14, 2009How 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 RepliesVS 2008 CheckBox Always Believes It Is Unchecked?
Oct 3, 2010I have a very stubborn check box . Let me tell you its story :There is Form1 with a button leading to Form2 . On Form2 there is located that stubborn check box I was telling you about . That check box has code in its CheckedChange event and accordingly to its Checked condition , it enables or disables some text boxes .Well , the first time Form2 is shown , that check box works fine : when I check it it enambles the text boxes and when I uncheck it , it disables those text boxes .Then , I press the button to return to Form1 . If needed , the code in the button is :Form1.ShowMe.CloseMy adventure starts when I show again Form2 ... This time the check box is acting weirdly . No matter if I check it or I uncheck it , it always disables the text boxes , as if it is constantly unchecked ! I can see it changing its checked state whenever I click on it , but it always runs the code to disable the text boxes.
I even used some break points in the code and found out that indeed it is the code that disables the text boxes that is called every time , no matter if the check box is checked or unchecked .I don't thing this has anything to do with the fact that this event is called by all the 4 check boxes on the form . After all , it is always the 1st check box that causes the problem (I can see it when moving the cursor over the genericindex variable) .
Javascript - Insert Checkbox Checked Value When Checked To Textbox As Comma Separated String
Nov 9, 2010Insert 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
CheckBox Unchecked - Clear Contents In RichTextBox
Jul 2, 2009I am using the following code for a checkbox, if checked it should print the text defined, unchceked, it clears the items in the ricktextbox. My problem is it prints fine (lets say it prints two lines) as defined, when I uncheck, it clears the text in rich text box, but when I check again, the text appears in the richtext box, but displayed from 4th line. I need to restart from the beginning/ or at least from the next available line. I cant use clear() since it erase all the contents as i have another 3 checkbox items placed.
If CheckBox1.Checked Then
richtextbox.SelectionColor() = Color.Blue
richtextbox.AppendText("Urgent:")
richtextbox.AppendText(CheckBox1.Text.ToString + vbNewLine)
Else
richtextbox.Refresh()
End If
User When He Checks One Checkbox The Other Two Are Unchecked By Default?
Jul 12, 2010I have a datagridview with 3 checkboxes, Yes, No and InV.At runtime, I want the user when he checks one checkbox the other two are unchecked by default. Therefore, at whatever one time ONLY one checkbox will be checked.
[Code]...
VS 2010 - New Form Opens Even When Checkbox Unchecked
Nov 16, 2009I'm trying to set my software up so that when I check the checkbox for winRAR to be installed, it'll pop up a new window asking if I want to install the 32 bit version or the 64 bit version. I have no problem getting the window to show up but than if I try to exit out of the window and than uncheck the box (in case it was accidentally checked) it'll just open the window again. I am thinking I have to tell vb that when I uncheck the box it shouldn't do anything.
Here's my code.
(I know that the Nothing under the Me.chk_rar.Checked = False doesn't work but I left that blank once and it just opened a bunch of windows and crashed my system. I know it says "E:Music" right now but I just pointed it there so that there was something there normally it'll point to the other window. If I need to created a new Form for every little window that I have for instance the little window that I want to pop up, do I need to create a new form just for that little window to ask which architecture is needed and than giving the options for 32 bit or 64 bit.
Private Sub chk_rar_CheckedChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles chk_rar.CheckedChanged
Me.chk_rar.Checked = True
Process.Start("E:Music")
Me.chk_rar.Checked = False
Nothing
End Sub
Way To Lock Textbox If Checkbox Is Check And Allow Data If It Is Unchecked
Mar 29, 2012I use a textbox for input unless one of the checkboxes is checked, then the textbox needs to have a value of 1 which I have working.What I need is a way to lock the textbox if the checkbox is check and allow data if it is unchecked.[code]
View 2 RepliesDebugging Shows That All Items In Checkbox List As Unchecked When There Are 3checked?
Aug 17, 2010so im dynamically populating a checkbox list. I have confirmed that my text and values are correct for each checkbox but when I check a few and click my event button when I loop through the items they are all set to select=false...
Dim resource As ListItem
Dim SelectedHashTable As New Hashtable
For Each resource In chkResources.Items
[code].....
Create A Checkbox In Form2 That Says If Checkbox 1 Is Checked Then Show Picture 1 In Form 1?
Apr 15, 2011I have a question, I can't really find the answer...Basically I have 2 FormsIn form number 1 I have 2 pictureboxes. I want to create a checkbox in form2 that says if checkbox 1 is checked then show picture 1 in form 1
View 1 RepliesCount The Total No. Of Asp.net Checkboxes, Checkboxes Checked, No. Of Checkboxes Remain Unchecked In Webform Using .net?
Dec 9, 2010How 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 RepliesGet Checked CheckBox Tag Value?
Aug 8, 2010I have grouped some checkbox in GroupBox1, 2, 3 respectively. Now I want to know the tag value ( I am using a TAG property to assign a some value to radio button ) of check box which is checked in either of the groupboxes.
View 1 RepliesHow To Checkbox Checked
Apr 24, 2012i have one checkbox that is not header checkbox of gridview and one gridview i want to click on check box gridview all row selected
View 1 RepliesIf Checkbox Is Checked Run 'something'
May 14, 2009I've got a simple Visual Basic 2008 Express Edition form which looks like this:[link Screenshot of simple form][1]I need some help with a skeleton script, which checks to see if each checkbox is checked or not. I've got a set of Word templates which all contain a macro.And I want to run the macro of each template, if the template exists.[code] know this pseudocode isn't correct at all, because I'm kind of a beginner, and designer over a programmer. But I've just started learning and I know this is pretty basic.it's just getting an overview of the logics in programming. And I think that getting to learn how to do this will help me with other things as well.
View 2 RepliesSet Several Checkbox To Checked?
Dec 27, 2010i'm trying to set several checkbox to be checked based on retrieved value from database.So when i load the data,if the value is the same with checkbox name,then it will be checked.Is it possible to do that?
View 2 RepliesCheck Whether Checkbox Is Checked Or Not?
Oct 3, 2010I have a datagridview with a checkbox column.i want to check whether checkbox is checked or not.If the checkbox is selected it should output as "True" in messagebox and if checkbox is not selected it should giving me a message "False".
View 3 RepliesCheckbox Checked If True
Apr 30, 2010I have the function below which I call onload, I want to be able to check the checkbox (chkactive) if the ProjectStatus is set to True, how can I do that please.[code]
View 4 RepliesCheckbox In Datagrid Not Able To Be Checked
May 17, 2011I have the following code:
[Code]...
and when a user clicks on cell4, it's supposed to add the value of "Holiday" to my database and all of the data from that line. What's happening is that I can't even click on the checkbox.
Checkbox In Datagrid Not Able To Be Checked?
May 17, 2011I have the following Private Sub holidaysaveButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles holidaysaveButton.Click For Each dr As DataGridViewRow In DataGridView1.Rows
[Code]...
and when a user clicks on cell4, it's supposed to add the value of "Holiday" to my database and all of the data from that line. What's happening is that I can't even click on the checkbox.
Checkbox Not Being Checked Using BindingSource?
Mar 20, 2010I am using a BindingSource to fill all the textboxes on my form. It is working for all the textboxes but for some reason it is not working for my check boxes. The value from the database is a boolean and I am setting the property like this.
SG.IsBifocal = CType(.Item(CN_IsBifocal), Boolean)
Is there anything special that needs to be done to bind to a check box?
Datagridview Checkbox Checked?
Mar 21, 2011I have the following code:
Code:
Private Sub dgProductAdj_CellContentClick(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles dgProductAdj.CellContentClick
If DirectCast(dgProductAdj.CurrentRow.Cells("Repeat"), DataGridViewCheckBoxCell).Value = True Then
For Each irow As DataGridViewRow In dgProductAdj.Rows
If irow.Index <> dgProductAdj.CurrentRow.Index Then
[Code]...
Getting CheckBox.Checked Values?
Jun 22, 2010I have a form that creates a row of checkboxes depending on the type of analysis the user wants to perform on the incoming file. I need to be able to determine if the checkbox is "checked" but I don't know how to do that when the controls are created at runtime.So right now I have a loop going through all the controls on the form and selecting the appropriate case: for instance chkbox1, combobox1, etc. Now I can access the values of the control by using Me.Controls.Item(chkbox1) but after that the only thing resemebling checked is .Text which wouldn't be accurate. how do you workaround the .Checked property of a checkbox when it is created at runtime?
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