I think this is a very dumb question sorry for this I am just doing some POC.  here is the code:    &lt;lightning-radio-group          name="radioGroup"         label="Radio Group"         options={options}         value={value}         required         type="radio"&gt;     &lt;/lightning-radio-group&gt;   &lt;lightning-button          variant="base"          label="Base"          title="Looks like a link"          onclick={handleClick}          class="slds-m-left_x-small"&gt;     &lt;/lightning-button&gt;   JS.  @track value;  get options() {     return [         { label: 'op1', value: 'op1' },         { label: 'op2', value: 'op2' },     ]; }  handleClick(event) {     console.log(this.value); }   The Console log is displaying me undefined...
If a lightning-radio-group has two options, and a user selects one, I want to programmatically have the UI changed back to the other one.  Link to a . (code copied below)  import { LightningElement, track } from 'lwc';  export default class RadioGroupRequired extends LightningElement {     @track value = 'option1';      get options() {         return [             { label: 'Option one', value: 'option1' },             { label: 'Option two', value: 'option2' },         ];     }      handleOnChange(evt) {         this.value = 'option1';         // how to make the UI select Option one?     } }   And the html:  &lt;template&gt;     &lt;lightning-radio-group name="radioGroup"                            label="Radio Group"                            options={options}                            value={value}                            required                            type="button"                            onchange={handleOnChange}&gt;&lt;/lightning-radio-group&gt;                             value={value} &lt;/template&gt;     I think that there is no rerendering because the bind variable, {value} doesn't actually change. However, the selected state of the lightning-radio-group does, and I want to be able to change it back. How can that be achieved?   I did not notice any methods or attributes that would seem to do the trick in the .
Since I updated Windows to 8.1 my Grub menu disappeared. I ran Ubuntu using Live USB, I used Boot-Repair but something went wrong. If I click on Reccomended repair I get this error:     GPT detected. Please create a BIOS-Boot partition (>1MB, unformatted filesystem, bios_grub flag). This can be performed via tools such as Gparted. Then try again. Alternatively, you can retry after activating the [Separate /boot/efi partition:] option.   So I tried to set my sda9 (I think that it's the Ubuntu system partition, since it's ext4) with the bios_grub flag and then to run Boot-Repair again. It didn't work.  I don't know what to do. My Grub was working fine (using UEFI) before I updated Windows.  I removed the bios_grub flag. Then I used fsck and it didn't find any error. So I tried again with Boot-Repair but it always gives me the "GPT detected" error. My boot is on UEFI mode, Secure Boot is "off".  When I boot my PC with SecureBoot OFF, I can reach the GRUB menu. But it's empty (the only voice is "System Setup").  I mounted my Ubuntu system disk:  sudo mount /dev/sda9 /mnt   and the other things:  sudo mount --bind /dev /mnt/dev sudo mount --bind /proc /mnt/proc sudo mount --bind /sys /mnt/sys   I logged on the system with chroot:  sudo chroot /mnt   I re-installed grub:  grub-install /dev/sda update-grub2   But it still doesn't work. How to split a string with any whitespace chars as delimiters Getting a closed form from $\sum_{i=1}^{n-1} \sum_{j=i+1}^{n} \sum_{k=1}^{j} 1$ Fractional Scaling 18.04 LTS If in a topological space only finite subsets are compact sets, is it then the discrete topological space?   Thank you. Rewrite code to make it faster Java Mail API - Encoding problems Fractions with large elements What is best practice for typesetting fractions with large objects in the numerator and denominator?  For example, fractions with limits, integrals, summations, etc... cause the expressions to look contracted and somewhat odd.  I understand that it is probably best to leave this as is when writing mathematics inline, but as a stand-alone fraction I feel it would be much less distracting if the symbols were typeset at normal size and the fraction was given more height in which to place itself.  Are there standards (for pure mathematics) regarding this problem? And what are the options - if it's generally permitted - for expanding the fraction size to incorporate large objects?    Example  \frac{\sum_{i=0}^{n} i^2}{\iint_{D}\frac{\partial (x,y)}{\partial (u,v)}\,\mathrm{d}u\,\mathrm{d}v}   Both the summation and the integral look somewhat cramped. Simple animation using C#/Windows Forms I need to knock out a quick animation in C#/Windows Forms for a Halloween display.  Just some 2D shapes moving about on a solid background.  Since this is just a quick one-off project I really don't want to install and learn an entire new set of tools for this.  (DirectX dev kits, Silverlight, Flash, etc..)  I also have to install this on multiple computers so anything beyond the basic .Net framework (2.0) would be a pain in the arse.  For tools I've got VS2k8, 25 years of development experience, a wheelbarrow, holocaust cloak, and about 2 days to knock this out.  I haven't done animation since using assembler on my Atari 130XE (hooray for page flipping and player/missile graphics!)  Advice?  Here's some of the things I'd like to know:   I can draw on any empty widget (like a panel) by fiddling with it's OnPaint handler, right?  That's how I'd draw a custom widget.  Is there a better technique than this? Is there a page-flipping technique for this kind of thing in Windows Forms?  I'm not looking for a high frame rate, just as little flicker/drawing as necessary.   Thanks.  Post Mortem Edit ... "a couple of coding days later"  Well, the project is done.  The links below came in handy although a couple of them were 404.  (I wish SO would allow more than one reply to be marked "correct").  The biggest problem I had to overcome was flickering, and a persistent bug when I tried to draw on the form directly.   Using the OnPaint event for the Form: bad idea.  I never got that to work; lots of mysterious errors (stack overflows, or ArgumentNullExceptions).  I wound up using a panel sized to fill the form and that worked fine. Using the OnPaint method is slow anyway.  Somewhere online I read that building the PaintEventArgs was slow, and they weren't kidding.  Lots of flickering went away when I abandoned this.  Skip the OnPaint/Invalidate() and just paint it yourself.  Setting all of the "double buffering" options on the form still left some flicker that had to be fixed.  (And I found conflicting docs that said "set them on the control" and "set them on the form".  Well controls don't have a .SetStyle() method.)  I haven't tested without them, so they might be doing something (this is the form):      this.SetStyle(ControlStyles.UserPaint, true);     this.SetStyle(ControlStyles.OptimizedDoubleBuffer, true);     this.SetStyle(ControlStyles.AllPaintingInWmPaint, true);    So the workhorse of the code wound up looking like (pf is the panel control):      void PaintPlayField()     {         Bitmap bufl = new Bitmap(pf.Width, pf.Height);         using (Graphics g = Graphics.FromImage(bufl))         {             g.FillRectangle(Brushes.Black, new Rectangle(0, 0, pf.Width, pf.Height));             DrawItems(g);             DrawMoreItems(g);             pf.CreateGraphics().DrawImageUnscaled(bufl, 0, 0);         }     }   And I just called PaintPlayField from the inside of my Timer loop.  No flicker at all. Pass ALL Arguments from Bash Script to Another Command Are there any other words similar to these words:  Award, Bestow, Donate, Grant, Give, Provide, Tax  ...that give a meaning of:  I freely give to you a portion what I have acquired or earned, without hesitation or expectation of anything in return. You are owed this, without question. There is no emotion involved with this transaction. It just is what it is.  For example: as a member of the Thief's Guild, 20% of everything you acquire will be ______ to the Guild.  Bestowed and Granted are very close...  Any other ideas? Two arrays in foreach loop I have a COM dll written in vb6. When I try to create a new object of a class module from this dll I get a Run timer error 430: Class does not support automation or does not support expected interface. 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I have installed Apache(LAMP) web server on my ubuntu machine and I want to do the above mentioned thing.I have tried creating symbolic links in the /var/www directory but it only shows files but not directories inside the directory linked.I want to redirect /var/www to my home folder so that I can access all the files and directories contained therein.Please help me. What are the criteria for questions to be selected for Hot Network Questions? How to get scroll position from GridView? How to get a normal application menu in the top- or titlebar in Gnome Let $f:(0,\infty) \to R$ be differentiable. Suppose that $\lim_{x\to\infty}(f(x)+f'(x))=L$. Show that $\lim_{x\to\infty} f(x) = L$ and $\lim_{x\to\infty} f'(x) = 0$. (Hint: Write $f(x) = e^xf(x)/e^x$ and use l’Hopital’s Rule.)    My working for $\lim_{x\to\infty}f'(x)=0$:  For $\lim_{x\to\infty}f'(x) = 0$, I let $f(x) = e^xf(x)/e^x$ and applied quotient rule which then cancels off $e^{2x}$ and I'm left with $\lim_{x\to\infty}(f(x)+f'(x)-f(x))$. Can I then equate this with $\lim_{x\to\infty} \left(f(x)+f'(x)\right) - \lim_{x\to\infty}f(x)$ which then gives $L-L=0$? Is this step correct? No custom off topic message when flagging on SO I have less than 3000 rep on StackOverflow. Now that the new closing changes are live, I cannot supply a custom off topic message:    I can enter a custom off topic flag message without issue here on meta, though it only has three canned off topic reasons, rather than five.  I'm not sure if this is the same for users with enough rep to vote to close directly, but the lack of a custom message eliminates the ability to use the correct flag reason in some cases.  For example, I wanted to flag , which is simply off topic on SO. However, I can't use a custom message, and none of the canned ones are appropriate.    appears to be the most up to date official information on custom reasons, and indicates that they are remaining in play for now.  supports that.  If this is by design, how should I flag such questions? This is not a case worth bothering the mods over, so I don't want to use a custom diamond attention flag.