constraints

问题 i made a simple circle programatically with cashapelayer in custom uiview class like this: class UserProfileCircleAnimated: UIView { private lazy var leftPhotoArc: CAShapeLayer = { let leftPhotoArc = CAShapeLayer() leftPhotoArc.lineWidth = 6 leftPhotoArc.strokeColor = UIColor.rgb(red: 232, green: 72, blue: 85, alpha: 1).cgColor leftPhotoArc.fillColor = nil leftPhotoArc.path = UIBezierPath(arcCenter: CGPoint(x: 25, y: 25), radius: 25 , startAngle: 2 * CGFloat(M_PI), endAngle: 0, clockwise:

问题 I've here a problem that I couldn't find a proper solution on my researches, maybe it's because I couldn't find out the exact terms to search for it, so if this is a duplicate I will delete it. My problem is I want to know if it is possible to avoid a combination of data between two fields. I will show the structure and the kind of data I want to avoid. It will be easier to understand. Table_A Table_B ------------------------ ------------------------------- id integer (PK) id integer (PK)

问题 Suppose x,y,z are int variables and A is a matrix, I want to express a constraint like: z == A[x][y] However this leads to an error: TypeError: object cannot be interpreted as an index What would be the correct way to do this? ======================= A specific example: I want to select 2 items with the best combination score, where the score is given by the value of each item and a bonus on the selection pair. For example, for 3 items: a, b, c with related value [1,2,1], and the bonus on

问题 So I'm trying to get the first and third button to take up the rest of the space of the tab bar and have the second button be a constant width. I'm getting close but I can't seem to quite get it. This is my first time adding constraints programmatically so I welcome constructive criticism. Here is the code. On the image each color is a button. - (void)setUpTabbarProperties { [self.tabBar setHidden: YES]; [self.customTabBarView setTranslatesAutoresizingMaskIntoConstraints: NO]; [self

问题 I am working on auto layout in my app.I have a functionality to increase the font size of entire app through slider movement.The issue is when i increase the font size the text of the label turns into ellipses. I have given the constraints to my label a fixed width and increasing variable height but this doesn't solve any problem. Do i need to give line break mode (word-wrap) and specify the number of lines for every text or there any other solution to this ? Any help will be appreciated. 回答1

问题 I have a node that have a constraint; to be more specific, it has an SCNLookAtConstraint : let constraint = SCNLookAtConstraint(target: scene.retriveNodeFromScene(cameraNodeName)) constraint.gimbalLockEnabled = false self.constraints = [constraint] But when I want to move node to other coordinates it just doesn't move. I don't receive any error, just nothing happens. I have made some tests, and if I remove constraint, everything is ok, node moves with no problem. So, what should I do? Is

问题 I'm trying simple experiment just to try how I can add constraints into an object. So, I create just a single UIView (yellow coloured) with vertical space constraint = 200 from storyboard like this : here's my interface file : #import <UIKit/UIKit.h> @interface ViewController : UIViewController @property (strong, nonatomic) IBOutlet UIView *screenView; @property (strong, nonatomic) IBOutlet UIView *container; @end and I want to programatically modify Vertical Space Constraint of _container by

问题 I have to change datatype of a column in SQL Server. So what are the constraints in doing? I know I have to remove index and other constraints? Do I have to remove not null check ? What other things do I have to check before altering the datatype? I need to remove the constraints and alter the table and then add the constraints again. Is this the right way to do so ? DROP INDEX UX_1_COMPUTATION ON dbo.Computation ALTER TABLE dbo.Computation ALTER COLUMN ComputationID NVARCHAR(25) CREATE

问题 It's not clear for me from the documentation if a db4o server in java without persistent class can handle unicity constraint, I see nothing saying no, but the way to configure it on the server we need the class on the classpath. (and I don't want that in that case). Same question for indexes ? Thanks in advance. 回答1: My recommendation: Don't do a db4o server without the persistent classes available. That leads to countless issues. Anyway, you should be able to just specify the full qualified

问题 I have two subviews in a view controller. I want the two subviews to be centered horizontally inside the main view, one on top of the other and also having the same leading space and trailing space with respect to the main view. One way I can do is to set the leading space and trailing space of the top subview with respect to the main view and also centering horizontally in the main view. After that, align the leading, trailing and center of the bottom subview with the top subview. The other