after I made a setup with my project and made it .exe in c#,i want to make my application(.exe) to open just once.Is there anyone who can help me with my problem ?thanks in advance.  I want to prevent my application from opening it again.
Using C# and WPF under .NET (rather than  or console), what is the correct way to create an application that can only be run as a single instance?  I know it has something to do with some mythical thing called a mutex, rarely can I find someone that bothers to stop and explain what one of these are.  The code needs to also inform the already-running instance that the user tried to start a second one, and maybe also pass any command-line arguments if any existed.
MySQL Prepared statements with a variable size variable list How would you write a prepared MySQL statement in PHP that takes a differing number of arguments each time? An example such query is:  SELECT `age`, `name` FROM `people` WHERE id IN (12, 45, 65, 33)   The IN clause will have a different number of ids each time it is run.  I have two possible solutions in my mind but want to see if there is a better way.  Possible Solution 1 Make the statement accept 100 variables and fill the rest with dummy values guaranteed not to be in the table; make multiple calls for more than 100 values.  Possible Solution 2 Don't use a prepared statement; build and run the query checking stringently for possible injection attacks. "Bring" vs. "take" in American English Why are there two tensions on my free body diagram? I need to read a properties files that's buried in my package structure in com.al.common.email.templates.  I've tried everything and I can't figure it out.  In the end, my code will be running in a servlet container, but I don't want to depend on the container for anything. I write JUnit test cases and it needs to work in both. The "Reputation &amp; Moderation" page on any site (/help/site-moderators) still refers to the company behind Stack Exchange as Stack Exchange and not Stack Overflow.     Moderators act as a liaison between the community and Stack Exchange the company.   Seeing as how the name change was recent, I'm not surprised this hasn't been caught yet, and I'm sure there are other instances of this around somewhere. Citations with no bibliography at the end How do you produce a document with citations (\citep, \citet) working properly in the paper but without a bibliography at the end?  I've come up with one solution that is bad because it breaks my makefile.  latex file.tex bibtex file # comment out \bibliography{} command latex file.tex   Similarly, is there a way to produce the bibliography with no accompanying text?  Again, I've come up with a solution: fill an otherwise blank .tex file with \nocite{} commands.  However, this is a pain because I have to keep two files synced by hand (and regular expressions to search for \citep{author1, author2} can be a huge pain when there are pagebreaks...). I am trying to build a custom Adventure Island. At this moment I am trying to limit the allowed items on this island. I'm trying to do this by filtering on a certain enchantment which is not item-specific.  For example.   When you want to filter an wooden sword with a custom name, you use this command:  /testfor @p[r=5] {Inventory:[{tag:{display:{Name:"Custom Sword"}}}]} &lt;   When you want to filter a wooden sword with a custom name and specific enchantement, you can use:  /testfor @p[r=5] {Inventory:[{tag:{display:{Name:"Custom Sword"},ench:[{id:16,lvl:1}]}}]} &lt;   But how can I filter on items with a specific enchantment on ANY item? I tried:  /testfor @p[r=5] {Inventory:[{tag:{ench:[{id:16,lvl:1}]}}]} &lt;   But this ain't work. Does anyone know how to solve this issue? How to access the correct `this` inside a callback? I left my cast iron pot on the gas stove, on high flame, and then forgot about it for 3 hours. It was empty and I was drying it before I oiled it to store it. After I discovered it and let it cool, I oiled it with a paper towel and all this rusty stuff came off and continues to come off. Is my pan ruined? What should I do? Reading console input in MonoDevelop Proof by induction of summation inequality: $1+\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+\dots+\frac1{2^n}\ge 1+\frac{n}2$ Prove by induction the summation of $\frac1{2^n}$ is greater than or equal to $1+\frac{n}2$.  We start with $$1+\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+\dots+\frac1{2^n}\ge 1+\frac{n}2$$ for all positive integers.   I have resolved that the following attempt to prove this inequality is false, but I will leave it here to show you my progress. In my proof, I need to define P(n), work out the base case for n=1, and then follow through with the induction step. Strong mathematical induction may be used.  This is equivalent to $$\sum_{k=0}^n\frac1{2^k}\ge 1+\frac{n}2\;.$$  Let $P(n)$ be summation shown above.   Base case for $n=1$, the first positive integer,   $$\sum_{k=0}^1\frac1{2^k}=\frac1{2^0}+\frac1{2^1}=1+\frac12=\frac32\ge 1+\frac12=\frac32\;,$$  so base case is true.  Induction step: Assume $P(n)$ is true and implies $P(n+1)$. Thus   $$\sum_{k=0}^{n+1}\frac1{2^k}\ge\frac1{2^{n+1}}+\sum_{k=0}^n\frac1{2^k}\ge 1+\frac{n+1}2\;.$$  This can be written as   $$\sum_{k=0}^{n+1}\frac1{2^k}\ge \frac1{2^{n+1}}+1+\frac{n}2\ge 1+\frac{n+1}2\;.$$  I work the math out but I get stuck contradicting my statement. Please show your steps hereafter so I can correct my mistakes. In classical logic, why is $(p\Rightarrow q)$ True if $p$ is False and $q$ is True? I have calculated AIC and AICc to compare two general linear mixed models; The AICs are positive with model 1 having a lower AIC than model 2.  However, the values for AICc are both negative (model 1 is still &lt; model 2).  Is it valid to use and compare negative AICc values? What does the , operator do in C? Does a shortcode with a single attribute have to use an array? I want to build a shortcode that takes a single attribute.  Everything online is telling me to make it using an array:  // Add Shortcode function bg_comparison_points_shortcode( $atts ) {     // Attributes     $atts = shortcode_atts(         array(             'custom_field' =&gt; '',         ),         $atts,         'comparison_points'     );     return bg_calculate_points($custom_field); } add_shortcode( 'comparison_points', 'bg_comparison_points_shortcode' );   But in my mind something like this would be much simpler  // Add Shortcode function bg_comparison_points_shortcode( $custom_field ) {     return bg_calculate_points($custom_field); } add_shortcode( 'comparison_points', 'bg_comparison_points_shortcode' );   Is there a problem doing this simpler version? Deriving Schrodinger equation from Klein-Gordon QFT with the definition $\psi(\textbf{x},t)\equiv \langle 0|\phi_0(\textbf{x},t)|\psi\rangle$ In the book "Quantum Field theory and the Standard Model" by Matthew Schwartz, , the position space wavefunction is defined as   $$\psi(x)=\langle 0|\phi(x)|\psi\rangle, \tag{2.82+2.83}$$  where $|\psi\rangle$ is any state in the Fock space. Then he uses the equations (i) $\partial_t^2\phi_0=(\nabla^2-m^2)\phi_0$ (i.e., the Klein-Gordon equation for the free massive scalar field $\phi_0(\textbf{x},t)$) and (ii) $[H,\phi_0]=-i\partial_t\phi_0$ to derive Eq. 2.85, in following 3 steps:  $$i\langle 0|\partial_t\phi_0(\textbf{x},t)|\psi\rangle=\langle 0|\int \frac{d^3\textbf{p}}{(2\pi)^3}\frac{\sqrt{\textbf{p}^2+m^2}}{\sqrt{2\omega_\textbf{p}}}(a_p e^{-ip\cdot x}-a^\dagger_p e^{ip\cdot x})|\psi\rangle\\ =\langle 0|\sqrt{m^2-\nabla^2}\phi_0(\textbf{x},t)|\psi\rangle.\tag{2.85}$$  This equation is used to successfully derive the Schrodinger equation in quantum mechanics for the state $\psi(\textbf{x},t)\equiv \langle 0|\phi_0(\textbf{x},t)|\psi\rangle$.   The first equality follows from differentiation of $\phi_0(x)$ w.r.t $t$. How does the second equality follow from the first? How are the inputs (i) and (ii) are utilized to derive the second equality from the first? Is it true that the operator $$i\partial_t\sim\sqrt{m^2-\nabla^2}~?$$ If yes, what is the use of doing the middle step? How to format numbers as currency strings Find objects between two dates MongoDB Scale Space Between Multiple Objects If I have multiple objects selected can I use scaling to make the objects closer together (without rescaling the objects)? Do we have to tune the number of trees in a random forest?