categories

问题 I have a hierarchy of categories, where a category can have a single parent (and you can have multiple levels of children.) I'm investigating ways to display this information to the user and it seems like a basic vanilla tree layout is the most intuitive way to go. But I'm wondering if anyone can suggest other approaches. The requirements would be, 1) clearly demonstrate to the user the list's parent / child relationships 2) allow the user to easily move items around (whether by drag and drop

问题 I have the following dataframe, where pd.concat has been used to group the columns: a b C1 C2 C3 C4 C5 C6 C7 C8 0 15 37 17 10 8 11 19 86 1 39 84 11 5 5 13 9 11 2 10 20 30 51 74 62 56 58 3 88 2 1 3 9 6 0 17 4 17 17 32 24 91 45 63 48 Now I want to draw a bar plot where I only have two categories ( a and b ), and each category has four bars representing the average of each column. Columns C1 and C5 should have the same color, as should columns C2 and C6, and so forth. How can I do it with df

问题 I try to find the code (short code) in the woo comm plugin that made the list of all the product from one category, to be able to modify it... no luck after 1 hours, still no find. So i start coding it myself (reinventing the wheel) and here what i try to get get me all the product from category ID="151" and be able to output the name, the permalink etc etc... this is the code now, that return everything.... way too much ! and i don't know how to filter it { $args = array( 'post_type' =>

问题 As it currently stands, this question is not a good fit for our Q&A format. We expect answers to be supported by facts, references, or expertise, but this question will likely solicit debate, arguments, polling, or extended discussion. If you feel that this question can be improved and possibly reopened, visit the help center for guidance. Closed 7 years ago . It's requied to create a category with a new variable (of type NSArray). OriginalClass+Extension.h: @interface OriginalClass

问题 i'm trying to Add Categories to my Rails app, but don't quite know how to do this. I have many Pins(Images) and want the user to be able to assign a category on those Pins. ASSIGN not create, edit, or delete a Category, just selecting one for their Pin. Meaning that, When a user uploads a pin, he can choose from a dropdown list a Category. Then, another user can choose from the Menu a Category, and ONLY the Pins in this Category will be listed. How do i do this? Where to start ? Thank you 回答1

问题 I wanted to create a category on NSURLSession. The app compiles ok, but when I attempt to call the category methods I get -[__NSCFURLSession doSomething]: unrecognized selector sent to instance 0xbf6b0f0 <unknown>:0: error: -[NSURLSession_UPnPTests testCategory] : -[__NSCFURLSession doSomething]: unrecognized selector sent to instance 0xbf6b0f0 Very strange, here is a test class I built to show the issue. The category on the NSString works fine, but the category on NSURLSession fails to find

问题 I am using the code coming from this answer: Hiding tabs only for some products in WooCommerce single product pages Here is that code: add_filter( 'woocommerce_product_tabs', 'conditionaly_removing_product_tabs', 98 ); function conditionaly_removing_product_tabs( $tabs ) { // Get the global product object global $product; // Get the current product ID $product_id = method_exists( $product, 'get_id' ) ? $product->get_id() : $product->id; // Define HERE your targetted products IDs in this array

问题 I have a category on NSDate and it would be convenient if it could implement a protocol I previously created. Is this possible? what's the correct syntax for this? 回答1: Yes, that's possible. The syntax is: @interface NSDate (CategoryName) <ProtocolName> @end @implementation NSDate (CategoryName) @end Here's Apple's documentation on the topic. It's also possible to do this using a class extension. I very much like this to privately conform to delegate protocols. Doing so hides the

问题 I want to use a selector on an NSObject instance without the need for an implemented protocol. For example, there's a category method that should set an error property if the NSObject instance it's called on supports it. This is the code, and the code works as intended: if ([self respondsToSelector:@selector(setError:)]) { [self performSelector:@selector(setError:) withObject:[NSError errorWithDomain:@"SomeDomain" code:1 userInfo:nil]]; } However, the compiler doesn't see any method around

问题 Mountain Lion introduced new APIs, some of which we had implemented as categories in our project. For examples, we have a category NSColor+CGColorAdditions that implemented CGColor and colorWithCGColor: for NSColor . These methods have been added in Mountain Lion. Ideally, we would like to use these categories if the client OS is older than Mountain Lion, and not use them if it's Mountain Lion. How can we do this? Or is there a better alternative? 回答1: NSColor *_NSColor_colorWithCGColor_