Ios – How to rotate an UIImageView by 20 degrees

cocoa-touchiosiphoneuiimageviewuikit

What do I have to do, if I need to rotate a UIImageView? I have a UIImage which I want to rotate by 20 degrees.

The Apple docs talk about a transformation matrix, but that sounds difficult. Are there any helpful methods or functions to achieve that?

Best Answer

If you want to turn right, the value must be greater than 0 if you want to rotate to the left indicates the value with the sign "-". For example -20.

CGFloat degrees = 20.0f; //the value in degrees
CGFloat radians = degrees * M_PI/180;
imageView.transform = CGAffineTransformMakeRotation(radians);

Swift 4:

let degrees: CGFloat = 20.0 //the value in degrees
let radians: CGFloat = degrees * (.pi / 180)
imageView.transform = CGAffineTransform(rotationAngle: radians)

Related Solutions

Ios – How to develop for iPhone using a Windows development machine

It's certainly possible to develop on a Windows machine, in fact, my first application was exclusively developed on the old Dell Precision I had at the time :)

There are three routes;

Install OSx86 (aka iATKOS / Kalyway) on a second partition/disk and dual boot.
Run Mac OS X Server under VMWare (Mac OS X 10.7 (Lion) onwards, read the update below).
Use Delphi XE4 and the macincloud service. This is a commercial toolset, but the component and lib support is growing.

The first route requires modifying (or using a pre-modified) image of Leopard that can be installed on a regular PC. This is not as hard as you would think, although your success/effort ratio will depend upon how closely the hardware in your PC matches that in Mac hardware - e.g. if you're running a Core 2 Duo on an Intel Motherboard, with an NVidia graphics card you are laughing. If you're running an AMD machine or something without SSE3 it gets a little more involved.

If you purchase (or already own) a version of Leopard then this is a gray area since the Leopard EULA states you may only run it on an "Apple Labeled" machine. As many point out if you stick an Apple sticker on your PC you're probably covered.

The second option is more costly. The EULA for the workstation version of Leopard prevents it from being run under emulation and as a result, there's no support in VMWare for this. Leopard server, however, CAN be run under emulation and can be used for desktop purposes. Leopard server and VMWare are expensive, however.

If you're interested in option 1) I would suggest starting at Insanelymac and reading the OSx86 sections.

I do think you should consider whether the time you will invest is going to be worth the money you will save though. It was for me because I enjoy tinkering with this type of stuff and I started during the early iPhone betas, months before their App Store became available.

Alternatively, you could pick up a low-spec Mac Mini from eBay. You don't need much horsepower to run the SDK and you can always sell it on later if you decide to stop development or buy a better Mac.

Update: You cannot create a Mac OS X Client virtual machine for OS X 10.6 and earlier. Apple does not allow these Client OSes to be virtualized. With Mac OS X 10.7 (Lion) onwards, Apple has changed its licensing agreement in regards to virtualization. Source: VMWare KnowledgeBase

Ios – How to disable the UITableView selection

All you have to do is set the selection style on the UITableViewCell instance using either:

Objective-C:

cell.selectionStyle = UITableViewCellSelectionStyleNone;

[cell setSelectionStyle:UITableViewCellSelectionStyleNone];

Swift 2:

cell.selectionStyle = UITableViewCellSelectionStyle.None

Swift 3 and 4.x:

cell.selectionStyle = .none

Further, make sure you either don't implement -tableView:didSelectRowAtIndexPath: in your table view delegate or explicitly exclude the cells you want to have no action if you do implement it.

More info here and here

Best Answer

Related Solutions

Ios – How to develop for iPhone using a Windows development machine

Ios – How to disable the UITableView selection

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