Possible Duplicate: C# Cannot convert from IEnumerable<Base> to IEnumerable<Derived> I have D1 and D2 which derive from B. When i write var ls = (IEnumerable<B>)(cond?lsD1:lsD2); I get a runtime cast error. IIRC this is a well known problem. My question is 1) Is this allowed yet? perhaps in .NET 4? I have 2010 but my project ...
As from subject, I have an awt.List object. When I add something to the list I would like to scroll it down to show the last inserted object. For instance: myList.add("sometext"); myList.select(myList.getItemCount()-1); myList.showSelectedItem(); // Or something like that The documentation does not seem to list any method that does s...
I need to send email to my 5000 subscribers. What is the best way to do this ? 1) By using BCC ?: $from_addr = '[email protected]'; $mailing_list = '[email protected]', '[email protected]', '[email protected]; $message_subject = 'this is a test'; `$headers = array ("From" => $from_addr, "Bcc" => $mailing_lis...
I am selecting state from country and city from state. This is my country select box: <td width=""><select name="country" onChange="getState(this.value)" class="text_box_width_190"> <option value="0">Select Country</option> <? foreach($country as $row) { ?> <option value="<?=$row['dCountry_id']?>"...
Hi there! I'm working my way through adapting a template I have been given that is basically a list of products for sale. I want to change it from a top-down list into a table layout. I want to end up with something as follows- <div id= 'ladiesproducts'> <% ladies_products = hosting_products.find_all do |product| product.name.match("lad...
I have a list of numbers I am reading left to right. Anytime I encounter a sign change when reading the sequence I want to count it. X = [-3,2,7,-4,1,-1,1,6,-1,0,-2,1] X = [-, +, +, -, +, -, +, +, -, -,-,+] So, in this list there are 8 sign changes. When Item [0] (in this case -3) is negative it is considered a sign change. Also, a...
Hi I want to know that do "head" and "tail" store any value like the other nodes?? thanks ...
Why are listener lists (e.g. in Java those that use addXxxListener() and removeXxxListener() to register and unregister listeners) called lists, and usually implemented as Lists? Wouldn't a Set be a better fit, since in the case of listeners there's No matter in which order they get called (although there may well be such needs, but th...
Hi there. I need to take the results of a query: var query = from m in db.SoilSamplingSubJobs where m.order_id == id select m; and prepare as an ICollection so that I can have something like ICollection<SoilSamplingSubJob> subjobs at the moment I create a list, which isnt appropriate to my needs: query.ToList(); what do I do...
I have two lists in python and I want to know if they intersect at the same index. Is there a mathematical way of solving this? For example if I have [9,8,7,6,5] and [3,4,5,6,7] I'd like a simple and efficient formula/algorithm that finds that at index 3 they intersect. I know I could do a search just wondering if there is a better wa...
Is there a singular regular expression that can be used in, say, a text editor's search/replace dialog to reverse the order of the items in a list? For instance, take this list: First item Second item Third item Select it in a text editor like EditPad, bring up the search and replace box, apply a regex (run as a loop or not) and tu...
I have several projects where I build a dictionary from a small class. I'm using C# 2008, Visual studio 2008 and .net 3.5 This is the code: namespace ReportsTest { class Junk { public static Dictionary<string, string> getPlatKeys() { Dictionary<string, string> retPlatKeys = new Dictionary<string, stri...
My program has a static list of type classA. ClassA implements a threading timer that executes a task. The list may contain as many instances of classA as desired. Is this technique causing threading issues where the class instances can block each other? It that is the case how can I solve the that problem. ex: static List<MyClassType> ...
i want to fill the data of the charts from values i have in 2D array, one column will present the X-axis and the second is present the Y-axis.. i did it, but its not reading from the array, it gives me the default line when i run the application, i found a solution using List<>, i had an error, so if any one could help me in this, i will...
Where to get full list of libav* formats? ...
I have enum: public enum SymbolWejsciowy { K1 , K2 , K3 , K4 , K5 , K6 , K7 , K8 } and I want to create list of this enum public List<SymbolWejsciowy> symbol; but in my way to add enum to List: 1. SymbolWejsciowy symbol ; symbol.Add(symbol = SymbolWejsciowy.K1); 2. symbol.Add(SymbolWejsciowy.K1); I always ...
Hi! I have a list consisting of other lists and some zeroes, for example: x = [[1, 1, 2], [1, 1, 1, 2], [1, 1, 2], 0, 0, 0] I would like to generate all the combinations of this list while keeping the order of the inner lists unchanged, so [[1, 1, 2], 0, 0, [1, 1, 1, 2], [1, 1, 2], 0] is fine, but [[1, 1, 1, 2], [1, 1, 2], 0, 0, ...
Given a list of lists like this [[1,2,3],[a,b,c,d],[x,y]] generate all permutations of the flattened list, [1,2,3,a,b,c,d,x,y], such that the elements of each sublist occur in the same order. For example, this one is okay [a,1,b,2,x,y,3,c,d] but this one is not [y,1,2,3,a,b,c,x,d] because y must occur after x, that being how x a...
I can't edit or sort the list. How can I get that index? ...
I was instructed to prevent this from happening in a Python program but frankly I have no idea how this is even possible. Can someone give an example of how you can slice a list and insert something into it to make it bigger? Thanks ...