Search Results

Search found 6401 results on 257 pages for 'constant expression'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 65/257 | < Previous Page | 61 62 63 64 65 66 67 68 69 70 71 72  | Next Page >

  • Binding to element in WPF: can the Path expression do math?

    - by John
    Hi I'm trying to bind a control to the parent's Height/width property using ElementName and a Path. However, I don't want to bind to the actual height, but to exactly half the height. Can the Path expression do the math? e.g. Path={ActualHeight/2} I couldn't find a way to do that. IS there any other clever approach? Thanks!

    Read the article

  • How to use Regular Expression to extract information from a HTML webpage?

    - by user569248
    How to use Regular Expression to extract the answer "Here is the answer" from a HTML webpage like this? <b>Last Question:</b> <b>Here is the answer</b> ..:: Update ::.. Thanks everybody! Here is my solution by using BeautifulSoup since I'm using Python framework: response = opener.open(url) the_page = response.read() soup = BeautifulSoup(''.join(the_page)) paraText1 = soup.body.find('div', 'div_id', text = u'Last Question:') if paraText1: answer = paraText1.next

    Read the article

  • How To? Use an Expression Tree to call a Generic Method when the Type is only known at runtime.

    - by David Williams
    Please bear with me; I am very new to expression trees and lambda expressions, but trying to learn. This is something that I solved using reflection, but would like to see how to do it using expression trees. I have a generic function: private void DoSomeThing<T>( param object[] args ) { // Some work is done here. } that I need to call from else where in my class. Now, normally, this would be be simple: DoSomeThing<int>( blah ); but only if I know, at design time that I am working with an int. When I do not know the type until runtime is where I need the help. Like I said, I know how to do it via reflection, but I would like to do it via expression trees, as my (very limited) understanding is that I can do so. Any suggestions or points to sites where I can get this understanding, preferably with sample code?

    Read the article

  • How to create a dynamic Linq Join extension method

    - by Royd Brayshay
    There was a library of dynamic Linq extensions methods released as a sample with VS2008. I'd like to extend it with a Join method. The code below fails with a parameter miss match exception at run time. Can anyone find the problem? public static IQueryable Join(this IQueryable outer, IEnumerable inner, string outerSelector, string innerSelector, string resultsSelector, params object[] values) { if (inner == null) throw new ArgumentNullException("inner"); if (outerSelector == null) throw new ArgumentNullException("outerSelector"); if (innerSelector == null) throw new ArgumentNullException("innerSelector"); if (resultsSelector == null) throw new ArgumentNullException("resultsSelctor"); LambdaExpression outerSelectorLambda = DynamicExpression.ParseLambda(outer.ElementType, null, outerSelector, values); LambdaExpression innerSelectorLambda = DynamicExpression.ParseLambda(inner.AsQueryable().ElementType, null, innerSelector, values); ParameterExpression[] parameters = new ParameterExpression[] { Expression.Parameter(outer.ElementType, "outer"), Expression.Parameter(inner.AsQueryable().ElementType, "inner") }; LambdaExpression resultsSelectorLambda = DynamicExpression.ParseLambda(parameters, null, resultsSelector, values); return outer.Provider.CreateQuery( Expression.Call( typeof(Queryable), "Join", new Type[] { outer.ElementType, inner.AsQueryable().ElementType, outerSelectorLambda.Body.Type, innerSelectorLambda.Body.Type, resultsSelectorLambda.Body.Type }, outer.Expression, inner.AsQueryable().Expression, Expression.Quote(outerSelectorLambda), Expression.Quote(innerSelectorLambda), Expression.Quote(resultsSelectorLambda))); } I've now fixed it myself, here's the answer. Please vote it up or add a better one.

    Read the article

  • Passing in a lambda to a Where statement

    - by sonicblis
    I noticed today that if I do this: var items = context.items.Where(i => i.Property < 2); items = items.Where(i => i.Property > 4); Once I access the items var, it executes only the first line as the data call and then does the second call in memory. However, if I do this: var items = context.items.Where(i => i.Property < 2).Where(i => i.Property > 4); I get only one expression executed against the context that includes both where statements. I have a host of variables that I want to use to build the expression for the linq lambda, but their presence or absence changes the expression such that I'd have to have a rediculous number of conditionals to satisfy all cases. I thought I could just add the Where() statements as in my first example above, but that doesn't end up in a single expression that contains all of the criteria. Therefore, I'm trying to create just the lambda itself as such: //bogus syntax if (var1 == "something") var expression = Expression<Func<item, bool>>(i => i.Property == "Something); if (var2 == "somethingElse") expression = expression.Where(i => i.Property2 == "SomethingElse"); And then pass that in to the where of my context.Items to evaluate. A) is this right, and B) if so, how do you do it?

    Read the article

  • Java: refactoring static constants

    - by akf
    We are in the process of refactoring some code. There is a feature that we have developed in one project that we would like to now use in other projects. We are extracting the foundation of this feature and making it a full-fledged project which can then be imported by its current project and others. This effort has been relatively straight-forward but we have one headache. When the framework in question was originally developed, we chose to keep a variety of constant values defined as static fields in a single class. Over time this list of static members grew. The class is used in very many places in our code. In our current refactoring, we will be elevating some of the members of this class to our new framework, but leaving others in place. Our headache is in extracting the foundation members of this class to be used in our new project, and more specifically, how we should address those extracted members in our existing code. We know that we can have our existing Constants class subclass this new project's Constants class and it would inherit all of the parent's static members. This would allow us to effect the change without touching the code that uses these members to change the class name on the static reference. However, the tight coupling inherent in this choice doesn't feel right. before: public class ConstantsA { public static final String CONSTANT1 = "constant.1"; public static final String CONSTANT2 = "constant.2"; public static final String CONSTANT3 = "constant.3"; } after: public class ConstantsA extends ConstantsB { public static final String CONSTANT1 = "constant.1"; } public class ConstantsB { public static final String CONSTANT2 = "constant.2"; public static final String CONSTANT3 = "constant.3"; } In our existing code branch, all of the above would be accessible in this manner: ConstantsA.CONSTANT2 I would like to solicit arguments about whether this is 'acceptable' and/or what the best practices are.

    Read the article

  • Creating a sort function for a generic list

    - by Andrey
    I have a method for sorting generic lists by the object fields: public static IQueryable<T> SortTable<T>(IQueryable<T> q, string sortfield, bool ascending) { var p = Expression.Parameter(typeof(T), "p"); if (typeof(T).GetProperty(sortfield).PropertyType == typeof(int?)) { var x = Expression.Lambda<Func<T, int?>>(Expression.Property(p, sortfield), p); if (ascending) q = q.OrderBy(x); else q = q.OrderByDescending(x); } else if (typeof(T).GetProperty(sortfield).PropertyType == typeof(int)) { var x = Expression.Lambda<Func<T, int>>(Expression.Property(p, sortfield), p); if (ascending) q = q.OrderBy(x); else q = q.OrderByDescending(x); } else if (typeof(T).GetProperty(sortfield).PropertyType == typeof(DateTime)) { var x = Expression.Lambda<Func<T, DateTime>>(Expression.Property(p, sortfield), p); if (ascending) q = q.OrderBy(x); else q = q.OrderByDescending(x); } // many more for every type return q; } Is there any way I can collapse those ifs to a single generic statement? The main problem is that for the part Expression.Lambda<Func<T, int>> I am not sure how to write it generically.

    Read the article

  • How do I refer to a constant URL in my route configuration?

    - by Remnant
    Suppose I have the following within a webpage <% using (Html.BeginForm("ShowData", "Summary")) %> <% { %> <div class="dropdown"><%=Html.DropDownList("CourseSelection", Model.CourseList, new { @class = "dropdown", onchange="this.form.submit();" })%> </div> <% } %> When the user makes a selection from the dropdown the form is submitted and I would like it to link to another page with a URL as follows: http://localhost:1721/Summary I have the following routes: routes.MapRoute(null, "Summary", new { controller = "Summary", action = "ShowData", CourseSelection = (string) null }); routes.MapRoute("Default", "{controller}/{action}/{id}", new { controller = "Login", action = "Index", id = UrlParameter.Optional }); When a user selects an item in the dropdownlist, the URL returned is: http://localhost:1721/Summary/ShowData?CourseSelection = UserSelection Clearly the first route in the list is not being matched. I don't want the URL to show the action name and parameter. I simply want to show "Summary" which is what I have hard coded in the URL. How do I achieve this?

    Read the article

  • Any example on how to implement the new VerificationController and the KNOWN_TRANSACTIONS_KEY constant?

    - by Carles Estevadeordal
    I've been looking at implementing the new VerificationController to verify in-App-Purchases: http://developer.apple.com/library/ios/#releasenotes/StoreKit/IAP_ReceiptValidation/_index.html And I wonder if there is some example anywhere en how to validate a transaction, since it seems that the - (BOOL)verifyPurchase:(SKPaymentTransaction *)transaction; is not enough and it has to be implemented internally to verify the purchase when the data form the server is received. Another question is if anyone has a clue on what the KNOWN_TRANSACTIONS_KEY is and how to fill it, is it just the product id of the purchase?

    Read the article

  • How this is code is getting compiled even though we are using a constant which is defined later?

    - by GK
    In the following code DEFAULT_CACHE_SIZE is declared later, but it is used to assign a value to String variable before than that, so was curious how is it possible? public class Test { public String getName() { return this.name; } public int getCacheSize() { return this.cacheSize; } public synchronized void setCacheSize(int size) { this.cacheSize = size; System.out.println("Cache size now " + this.cacheSize); } private final String name = "Reginald"; private int cacheSize = DEFAULT_CACHE_SIZE; private static final int DEFAULT_CACHE_SIZE = 200; }

    Read the article

  • Constant CMS Session Expiry On 1&1 Cloud Server?

    - by leen3o
    I have a couple of 1&1's 'Dynamic Cloud Servers' and running Win2008R2 and they are setup as web servers, I have a number of Umbraco CMS installs on them and they have been running fine for over a year. On Saturday on BOTH servers, a very strange thing happened - As soon as I login to the CMS/Umbraco admin I am logged out with about 5 seconds? It's as if my session expires the moment I login? I have checked everything I can as I'm not really a server admin, and everything seems to be exactly as it was last week? Like I say this has happened EXACTLY the same time (Saturday) on TWO different servers? I'm just looking for ideas of what I should be looking for? Also the front end of the sites seem fine... Its only the backend when I login. I have gone to 1&1 about this, and as usual they have washed their hands saying its nothing to do with them - When I am certain it is. How can this happen on two different servers, and affect the same sites in exactly the same way? Any help, tips, things to try would be greatly appreciated.

    Read the article

  • Is there a standard literal constant that I can use instead of "utf-8" in C# (.Net 3.5)?

    - by Hamish Grubijan
    Hi, I would like to find a better way to do this: XmlNode nodeXML = xmlDoc.AppendChild( xmlDoc.CreateXmlDeclaration( "1.0", "utf-8", String.Empty) ); I do not want to think about "utf-8" vs "UTF-8" vs "UTF8" vs "utf8" as I type code. I would like to make my code less prone to typos. I am sure that some standard library has declatred "utf-8" as a const / readonly string. How can I find it? Also, what about "1.0"? I am assuming that major XML versions have been enumerated somewhere as well. Thanks!

    Read the article

  • How can I use the compile time constant __LINE__ in a string?

    - by John
    I can use __LINE__ as a method parameter just fine, but I would like an easy way to use it in a function that uses strings. For instance say I have this: 11 string myTest() 12 { 13 if(!testCondition) 14 return logError("testcondition failed"); 15 } And I want the result of the function to be: "myTest line 14: testcondition failed" How can I write logError? Does it have to be some monstrosity of a macro?

    Read the article

  • Should constant contructor aguments be passed by reference or value?

    - by Mike
    When const values are passed to an object construct should they be passed by reference or value? If you pass by value and the arguments are immediately fed to initializes are two copies being made? Is this something that the compiler will automatically take care of. I have noticed that all textbook examples of constructors and intitializers pass by value but this seems inefficient to me. class Point { public: int x; int y; Point(const int _x, const int _y) : x(_x), y(_y) {} }; int main() { const int a = 1, b = 2; Point p(a,b); Point q(3,5); cout << p.x << "," << p.y << endl; cout << q.x << "," << q.y << endl; } vs. class Point { public: int x; int y; Point(const int& _x, const int& _y) : x(_x), y(_y) {} }; Both compile and do the same thing but which is correct?

    Read the article

  • Construction an logical expression which will count bits in a byte.

    - by danatel
    When interviewing new candidates, we usually ask them to write a piece of C code to count the number of bits with value 1 in a given byte variable (e.g. the byte 3 has two 1-bits). I know all the common answers, such as right shifting eight times, or indexing constant table of 256 precomputed results. But, is there a smarter way without using the precomputed table? What is the shortest combination of byte operations (AND, OR, XOR, +, -, binary negation, left and right shift) which computes the number of bites?

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 61 62 63 64 65 66 67 68 69 70 71 72  | Next Page >