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macoscocoaappkitfoundation

macOS - [NSValue valueWithCGAffineTransform:]

How can I create an instance of NSValue that contains a CGAffineTransform?

UIKit provides [NSValue valueWithCGAffineTransform:], but AppKit does not.

Do I need to use the valueWithBytes:objCType: static method?

Solution

  • CGAffineTransform is a struct

    struct CGAffineTransform {
  CGFloat a, b, c, d;
  CGFloat tx, ty;
};

    The correct way how to handle structs is mentioned in Key-Value Coding Programming Guide - Representing Non-Object Values (Wrapping and Unwrapping Structures)

    CGAffineTransform transform;
NSValue *value = [NSValue valueWithBytes:&transform objCType:@encode(CGAffineTransform)];