I'm trying to use SqlDependencyEx it accepts the first argument as a connection string, if I use my DB connection string directly it works but I don't want to give it directly instead I want it to grab DefaultConnection using Configuration. but I'm getting this error     A field initializer cannot reference the non-static field, method, or   property 'SignalServer.connectionString' (CS0236)   public class SignalServer : Hub         {             public readonly TestController _testController;             public IConfiguration Configuration { get; }             string connectionString = "";              public SignalServer(TestController testController, IConfiguration configuration)             {                 Configuration = configuration;                 _testController = testController;                 connectionString = Configuration.GetConnectionString("DefaultConnection");             }              public async void NotifyConnection()             {                 await Clients.All.SendAsync("TestBrodcasting", _testController.GetAllApps());             }              SqlDependencyEx sqlDependency = new SqlDependencyEx(connectionString);          }   Update:  public class SignalServer : Hub {     public readonly TestController _testController;     public IConfiguration Configuration { get; }      public SignalServer(TestController testController, IConfiguration configuration)     {         Configuration = configuration;         _testController = testController;         SqlDependencyEx sqlDependency = new SqlDependencyEx(Configuration.GetConnectionString("DefaultConnection"), "dbName", "tablename");     }      public async void NotifyConnection()     {         await Clients.All.SendAsync("TestBrodcasting", _testController.GetAllApps());     }       private void RegisterNotification()     {         sqlDependency.TableChanged += OnDataChange;         sqlDependency.Start();     }      private void UnregisterNotification()     {         sqlDependency.Stop();         sqlDependency.TableChanged -= OnDataChange;     }      private void OnDataChange(object sender, SqlDependencyEx.TableChangedEventArgs e)     {      }      private void Dispose()     {         UnregisterNotification();     } }
Consider:  namespace WindowsApplication1 {     public partial class Form1 : Form     {         public Form1()         {             InitializeComponent();         }          private void button1_Click(object sender, EventArgs e)         {             //int[] val = { 0, 0};             int val;             if (textBox1.Text == "")             {                 MessageBox.Show("Input any no");             }             else             {                 val = Convert.ToInt32(textBox1.Text);                 Thread ot1 = new Thread(new ParameterizedThreadStart(SumData));                 ot1.Start(val);             }         }          private static void ReadData(object state)         {             System.Windows.Forms.Application.Run();         }          void setTextboxText(int result)         {             if (this.InvokeRequired)             {                 this.Invoke(new IntDelegate(SetTextboxTextSafe), new object[] { result });             }             else             {                 SetTextboxTextSafe(result);             }         }          void SetTextboxTextSafe(int result)         {             label1.Text = result.ToString();         }          private static void SumData(object state)         {             int result;             //int[] icount = (int[])state;             int icount = (int)state;              for (int i = icount; i &gt; 0; i--)             {                 result += i;                 System.Threading.Thread.Sleep(1000);             }             setTextboxText(result);         }          delegate void IntDelegate(int result);          private void button2_Click(object sender, EventArgs e)         {             Application.Exit();         }     } }   Why is this error occurring?     An object reference is required for the nonstatic field, method, or property 'WindowsApplication1.Form1.setTextboxText(int)
Uninstalling Ubuntu from Windows Dual Boot if I don't have Windows recovery CD I installed Ubuntu (I had already had Windows 8.1) from USB (I still have live Ubuntu on it). Is there a way I can uninstall Ubuntu in a way that my Windows will remain bootable? All the tutorials I have seen say that uninstalling ubuntu will delete GRUB also so I will need a Windows recovery CD to boot into it, but I don't have one. Is there a solution? I can't work out why Altium is doing this, or how to undo it, or how to make it stop doing it.  It happens when I use the 'Find Similar Objects... ' option; all of objects that it hasn't found are faded out and I can no longer select them.  Anyone know how to fix this?  Additionally, if anyone knows how to change, en masse, the components' footprint library to 'Any' through the SCH inspector, that'd be really helpful too. Kindle for PC via Wine I really want to get the Kindle PC program running on my computer so I can download, read, and manage my e-books. I realize that Calibre can be used to manage e-books and I do have that downloaded. However, Amazon won't let me download ebooks unless my PC is registered in their Kindle program and I'd like to just keep things streamlined.  I've viewed many tutorials and advice for setting it up. I have Wine, I have Kindle for PC, I set it to Win98, all of that. However, when I try to open KindlePC from the Wine menu or from the desktop icon, nothing happens. No error messages, nothing. I don't know what might be wrong. How can I make it work? Create longer arrows How do I install Komodo Edit? New to linux, help me install this program Komodo-Edit-7.1.0-10496-linux-x86_64  I'm running Ubuntu 12.04 64bit. What is the effect where some objects are a single bright color but the rest is black and white? There is an option to filter only one color (R,G,B,Y) in my camera. What I want to know is can this effect be achieved in photoshop? And what is this called? I tried googling monochrome and came up with nothing. My camera calls it part color. Im confused about fire. The way I see it :   Heat creates (kinetic) energy in mass and this creates stronger vibrations of atoms. When those vibrations are strong enough the electrons interact stronger due to electromagnetic forces. This causes the electrons to fly away. This is the creation of a plasma and the direction of most electrons is the direction of the flame. the shape and heat of the flame depends mainly on the amount of electrons and their velocity ( apart from the source of heat and the considered gas and solid material) the electrons move freely ( but not random ) in the flame. there is a chemical reaction going on that usually produces smoke or such. the entropy increases in all the above 6 steps and the process is repeated. the electromagnetic energy is converted into kinetic energy of the electron and conductivity in the plasma (flame). the moving electrons create an electromagnetic field.   That is more or less how I see it. What steps are ok ?  And the main question , why is there light involved ?  I mean why cant we just have kinetic energy of the electrons and a changing magnetic field ? Why are there photons ? If the electrons are in a high energy state why cant they just move faster instead of emitting a photon ???  Why is the light usually visible ? is that because of our structure of air ?  If the light is an electromagnetic wave why does the flame go up ? does that imply all electromagnetic waves go up ?? But electromagnetic waves are not influanced by gravity or buoyancy are they ??  What is the final destiny of the electrons and photons if the heat is gone ??  I am puzzled by this. Converse of Schur's Lemma in finite dimensional vector spaces I am trying to prove (or disprove) the converse of Schur's Lemma in finite dimensional vector spaces. I am not sure if it holds in this case, but I have tried to apply the idea that proves it in representation theory (see for example Theorem 4.3  that uses Maschke's theorem or in questions  and ).  The converse of Schur's Lemma in finite dimensional vector spaces is:     Let $V$ be a finite dimensional vector space over the complex numbers. Let $S$ be a set of endomorphisms of $V$ and assume that every endomorphism $A$ of $V$ such that $$AB=BA\text{ for all }B\in S$$ is of the form $\lambda I, \ \lambda\in\mathbb{C}$. Then $V$ is a simple $S$-space.   (*an endomorphism of $V$ is a linear operator from $V$ to $V$  *$V$ is a simple $S$-space if the only $S$-invariant subspaces of $V$ are $V$ itself and the zero subspace)  What I've tried so far:  Assume to the contrary that $V$ is not a simple $S-$space. Then, there exists a subspace $W$ of $V$ such that $W\not =\{0\}$, $W\not= V$ and $W$ is $S$-invariant. Let $W'=V\setminus W$. Then, since $V$ is finite, we can easily prove that $V=W\oplus W'$ (this is my attempt to translate Maschke's theorem in vector spaces). Consequently, for every $v\in V$, there exists unique $w\in W$ and $w'\in W'$, such that $v=w+w'$. Define the projection $P:V\rightarrow V$ by $Pv=w$ for every $v\in V$.   What is left to prove is that $PB=BP$ for all $B\in S$. Then $P$ is clearly not a scalar and thus we have the contradiction we are looking for.  There is a difficulty in showing that $PB=BP$ for all $B\in S$, because $W'$ might be $S$-invariant or not. More precisely:   Let $v\in V=W\oplus W'$ and $v\not =0_V$.  If $v\in W$ then $Bv\in W$ because $W$ is $S$-invariant, therefore: $PBv=Bv$ and $BPv=Bv$.  If $v\in W'$ then $Pv=0$, hence $BPv=B\cdot 0=0$, and  (i) if $Bv\in W'$ then $PBv=0$.  (ii) if $Bv\in W$ then $PBv=Bv$ and this is where the problem occurs.  Any hints, ideas or counterexamples would be very helpful. How to control the mouse in Mac using Python? What would be the easiest way to move the mouse around (and possibly click) using Python on OS X?    This is just for rapid prototyping, it doesn't have to be elegant. Linear regression with non-symmetric cost function? I want to predict some value $Y(x)$ and I am trying to get some prediction $\hat Y(x)$ that optimizes between being as low as possible, but still being larger than $Y(x)$. In other words: $$\text{cost}\left\{ Y(x) \gtrsim \hat Y(x) \right\}  &gt;&gt; \text{cost}\left\{ \hat Y(x) \gtrsim Y(x) \right\}  $$  I think a simple linear regression should do totally fine. So I somewhat know how to implement this manually, but I guess I'm not the first one with this kind of problem. Are there any packages/libraries (preferably python) out there doing what I want to do? What's the keyword I need to look for?  What if I knew a function $Y_0(x) &gt; 0$ where $Y(x) &gt; Y_0(x)$. What's the best way to implement these restrictions? Solve $p_4(x) = x^4 −(2m + 4)x^2 + (m−2)^2 $such that $p_4$ is a product of two non-constant integer-coeficient polynomials I'm having trouble getting the starting idea for a problem I've been presented with:  I need to find values for m (integer) such that the following polynomial     $p_4(x) = x^4 −(2m + 4)x^2 + (m−2)^2$; $m$ is integer   can be described as the product of two non-constant integer-coeficient polynomials.  Any help/pointers/tips on how to go about this are greatly appreciated!  Edit: I meant polynomials with integer coeficients, but for some reason typed positive. I am on Ubuntu 12.04 64-bits  I accidentally deleted a NTFS 255 GB partition using Gparted, and yes it contains LOTS of important data.  Upon realizing the deletion I haven't yet created any file-system on it. So it still shows Unallocated.    I tried Testdisk , but it shows entire partitions created from the beginning.  This sdb is my secondary drive with Xubuntu and Kubuntu on it. And that 255 GB NTFS  partition was cross platform storage drive.  I am currently in sda with Ubuntu and Win7 in dual boot, which enables me to use it as Safe recovery option rather then Live USB drive.   First ,  should i allocate it to ? file-System for better recovery .  Second , i really need to recover data from this drive so please give me possible  suggestions and proven methods of data recovery.  Third ,does Testdisk requires deleted partition to be allocated for its recovery .  I am currently trying the answer seen here  with Testdisk scanning for partition second time, hoping to recover it.   It looks a duplicate but i can't confirm if the OP got it right. Since my first doubt is to allocate it or not.  If any clarification required please do comment ,i will add it.  Edit: TestDisk deeper search results.      The following partitions can't be recovered:          Partition               Start        End    Size in sectors     &gt;  HPFS - NTFS          22241 107 11 55592   3 27  535777280        FAT32 LBA            274460 158 19 460576 228 16 2989957948  NTFS, 274 GB / 255 GiB &amp; for FAT32 LBA 1530 GB / 1425 GiB Calculate the limit including binomial coefficients I stumbled upon a  with the following paragraph:     MBIE has launched an investigation into claims Chinese galvanised   steel coil imports have been dumped on the local market, causing   "material injury" to New Zealand industry, and the case will end up on   the table of newly appointed Commerce Minister Jacqui Dean.   I thought that sentence was grammatically wrong because the author should put the word "that" (as a conjunction) right after the word "claim". I don't see why the author could drop the conjunction. Is this a prevailing phenomenon in American or Australian English? Java Manifest.mf classpath issues I've been trying to run a jar file - let's call it test.jar - that uses the Sybase jconn3.jar on a Unix system.  I have created a MANIFEST.MF file that has the following:  Class-Path: $SYBASE/jConnect-6_0/classes/jconn3.jar commons-net-1.3.0.jar   This gives a ClassNotFoundError. $SYBASE is the system variable that points to /opt/sybase13; I've also tried the following:  Class-Path: /opt/sybase13/jConnect-6_0/classes/jconn3.jar commons-net-1.3.0.jar   and  Class-Path: opt/sybase13/jConnect-6_0/classes/jconn3.jar commons-net-1.3.0.jar   However, if I copy the jconn3.jar file from the $SYBASE/jConnect-6_0/classes to the same directory as test.jar, and update my MANIFEST.MF to read as follows:  Class-Path: jconn3.jar commons-net-1.3.0.jar   The application runs as expected.  Now, I've been able to verify the jconn3.jar file works by copying it locally; my MANIFEST.MF file includes the path to my Main-Class, so that's not at issue here.  What do you think could be the problem? I've been looking at this thing for too long now. Thanks! I have Ubuntu 14.04 and two monitors. When I open applications I need some of them to be on the primary monitor and others On the secondary. At the moment, apps always open in the primary monitor.   I have dash icons only on one (left) display, so I can't launch apps using the cursor or active window setting from Compiz. Cannot get specific WMS to display in Leaflet or OpenLayers 3 How can I prove that $n^7 - n$ is divisible by $42$ for any integer $n$? I can see that this works for any integer $n$, but I can't figure out why this works, or why the number $42$ has this property. Biometric information for a UK visitor visa for the second time I submitted my biometric information when I applied for (and successfully received) the UK visitor visa.  Now, the visa has expired and I would like to apply for it again.   Do I need to submit my biometric information again?  Will the process be the exact same as before? How to find out why "context is incorrect"?