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问题 In Swift, there is Raw Value in Enumeration and Default Value in class and structure. What's the different? Can someone explain that for me? Ex. of Raw Values of Enumeration (From the Office Swift Document) enum ASCIIControlCaracter: Character { case Tab = "\t" case LineFeed = "\n" case CarriageReturn = "\r" } 回答1: From Apple docs: Raw Values The barcode example in Associated Values shows how cases of an enumeration can declare that they store associated values of different types. As an

问题 I would like to do something like this: function readUser($aUser = loadDefaultUser()){ //doing read User } I find that it will display a error to me, how can I pass a function return as a default value? Thank you. 回答1: Yes, you can provide a default argument. However, the default argument "must be a constant expression, not (for example) a variable, a class member or a function call." You can fake this behaviour by using some constant value for the default, then replacing it with the results

问题 I know this may sound strange, but I want to retrieve the system default contact picture. You know, that icon that's used when there is no picture for the contact. It differs between different versions of Android, but it's generally a blank face, or a grey android, or whatever. Can I get that image from the system and use it in my app? 回答1: You can find them in the drawable folder of the resources that come with the emulator. \android-sdk\platforms\android-v#\data\res\drawable\ 回答2: I dont

问题 I know that class members with default access control can be accessible at package level but i'm confused about what does package level access actually mean. If default members can be accessed at package level then shouldn't i be visible in class Test2 in following example? class 1- package pkg1; public class Test { int i=0; } class 2- import pkg1.Test; public class Test2 { void get(){ Test t = new Test(); t.i=0; } } Please help me getting this concept. Thanks in advance. 回答1: Package level

问题 I've been searching for a way to have users set my program as the default to open files for awhile and found nothing. I have a program that is supposed to be universal for Mac, Windows and Linux, so I don't want to use a method that only works with one OS. So how can I give users the ability to set a Java app as the default file opener? Would I use the Desktop class? 回答1: No Java does not support this. You would have to write a small app for every OS that you want to support in its native

问题 Can I use default arguments in a constructor like this maybe Soldier(int entyID, int hlth = 100, int exp = 10, string nme) : entityID(entyID = globalID++), health(hlth), experience(exp), name(nme = SelectRandomName(exp)) { } I want for example exp = 10 by default but be able to override this value if I supply it in the constructor otherwise it should use the default. How can I do this, I know my approach does not work.... If I supply any value in the initialization list no matter whatever I

问题 When I have the following: <a name='test'></a> ...and load it in a browser, I can append #test to the URL and the browser will scroll so that the <a> is at the top of the page. However, I would like to change this behavior (using JavaScript if possible) so that using the hash does not scroll the page - I'd like it to simply do nothing. Is there a way to do that without removing the <a> element? Update: I need the browser to still send onhashchange() events but without scrolling to the <a>

问题 In couch base URL, e.g. server:port/pools/default what exactly a couch base pool is. Will it always be default or we can change it. There is some text written there http://www.couchbase.com/docs/couchbase-manual-1.8/couchbase-admin-restapi-key-concepts-resources.html but I cannot really get it 100%. Please anyone can explain. 回答1: A long time ago the Couchbase engineers intended to build out a concept of having pools similar to zfs pools, but for a distributed database. The feature isn't dead

问题 I am very happy with the spring-boot project so far, but I'd like to develop a deeper understanding, of how everything is glued together. Using spring-boot-starter-web, spring-boot-starter-data-jpa and hateoas I was able to assemble a nice working REST backend. But I am wondering, how it is done, that e.g. a DataIntegrityViolation is converted nicely into a JSON output like this. I actually like the info being provided, but I wonder, how I could reuse the DataObject being converted to JSON. I

问题 We all have been easily able to do this prior to Windows 8 (in XP/VISTA/WIN7) with few changes in Registry and it was done. With Windows 8 it's not that easy (I'm yet to figure it out how). Windows 8 too has few registry settings to be changed mentioned below, but along with this it also stores a unique Hash for every computer. Can any body help me to possibly create this hash for every computer or with some API provided by Microsoft to set default browser ('SetAppAsDefaultAll' does not work)