constraints

问题 I'm having some issues of figuring out when the auto-contraints setup on a XIB are applied in the view setup process. For more explanation: I've setup a XIB for a view I set the "Simulated Metrics" Size to iPhone 3.5-Inch I've added auto-constraints to the subviews inside this view In the View Controller I perform certain operations dependent on the subview ( IBOutlet ) frames/bounds in the viewDidLoad method In the View I perform certain operations dependent on the subview ( IBOutlet )

问题 I have a generic class: public class Foo<T> where T: Interface { } the interface that T is being forced to implement has 2 static methods defined inside of it. in the constructor I want to be able to basically do the following: public Foo() { value1 = T.staticmethod1(); value2 = T.staticmethod2(); } This cannot be accomplished with the psuedocode I have posted above. Is it not possible to call these static methods in this way? 回答1: You may be able to use extension methods. This technique has

问题 I did not create the database I'm working with, but I would like to see the details of a check constraint. I know a check constraint on a column is enforcing a set of specific values, and I'd like to know what those values are. For example, if a check constraint is enforcing the character 'Y' and 'N', I want to be able to query the database and see that the accepted values are 'Y' and 'N.' Is this possible to do through a query? 回答1: select constraint_name,search_condition from all

问题 I have this table CREATE TABLE [dbo].[CityMaster]( [CityID] [int] NOT NULL, [City] [varchar](100) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL, [BranchId] [varchar](10) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL CONSTRAINT [DF__CityM__Branc__74444068] DEFAULT ((0)), [ExternalBranchId] [varchar](max) COLLATE SQL_Latin1_General_CP1_CI_AS NULL, CONSTRAINT [PK_CityMaster] PRIMARY KEY CLUSTERED ( [City] ASC, [BranchId] ASC ), CONSTRAINT [uk_citymaster_cityid_branchid] UNIQUE NONCLUSTERED (

问题 Beforehand I have to say that I actually got the visible effect I've wanted but not in a satisfying way since, right now, constraints need to be "broken" instead of being properly updated. I got a ViewController which holds a UITableView. The height of that tableView can vary from 0 (not visible) to whatever the number of rows it holds is. The height is calculated in the ViewController's viewDidLoad() by multiplying the current number of rows by the row's height. The first thing I've tried

问题 I have four Database Tables like these: Book ID_Book |ID_Company|Description BookExtension ID_BookExtension | ID_Book| ID_Discount Discount ID_Discount | Description | ID_Company Company ID_Company | Description Any BookExtension record via foreign keys points indirectly to two different ID_Company fields: BookExtension.ID_Book references a Book record that contains a Book.ID_Company BookExtension.ID_Discount references a Discount record that contains a Discount.ID_Company Is it possible to

问题 I have four Database Tables like these: Book ID_Book |ID_Company|Description BookExtension ID_BookExtension | ID_Book| ID_Discount Discount ID_Discount | Description | ID_Company Company ID_Company | Description Any BookExtension record via foreign keys points indirectly to two different ID_Company fields: BookExtension.ID_Book references a Book record that contains a Book.ID_Company BookExtension.ID_Discount references a Discount record that contains a Discount.ID_Company Is it possible to

问题 Closed . This question needs to be more focused. It is not currently accepting answers. Want to improve this question? Update the question so it focuses on one problem only by editing this post. Closed 3 years ago . I am working on application which will work only horizontally and doing everything programmatically. I am having a imageview, two textfield and two buttons but I don't know how to set constraints on these textfields and buttons, means when I am using in iPhone 5s then it is fine

问题 How to drop a foreign key if I have not named it during creation create table abc( id number(10), foreign key (id) references tab(roll) ); even alter table abc drop foreign key mn_ibfk_1; is not working for me. I am using Oracle 10g. 回答1: As you did not specify a constraint name, Oracle generated one for you (something like SYS_034849548 ). You need to find the constraint name in order to be able to drop it: select constraint_name from user_constraints where table_name = 'ABC' and constraint

问题 I have UIViewController which looks like this: I set all the relevant constraints . I'm trying to shift the UIView up when the keyboard shows up - when I click on the UITextfields below. I have the following code: static func addRemoveKeyboardObserver(addObserver: Bool, keyboardMargin: CGFloat, view: UIView?) { Utils.keyboardMargin = keyboardMargin Utils.heightChangingView = view if addObserver { NotificationCenter.default.addObserver(self, selector: #selector(Utils.keyboardWillChange