在Swift中設置CIFilter

Question

如何將以下ObjC代碼的最后一行轉換為Swift：

CGAffineTransform transform = CGAffineTransformIdentity;
CIFilter *clampFilter = [CIFilter filterWithName:@"CIAffineClamp"];

[clampFilter setValue:[NSValue valueWithBytes:&transform objCType:@encode(CGAffineTransform)] forKey:@"inputTransform"];

以下行

clampFilter.setValue(transform, forKey: "inputTransform")

產生

Type 'CGAffineTransform' does not conform to protocol 'AnyObject'

Answer 1

NSValue有一個構造函數，它接受一個CGAffineTransform參數：

let transform = CGAffineTransformIdentity
let clampFilter = CIFilter(name: "CIAffineClamp")

let val = NSValue(CGAffineTransform: transform)
clampFilter.setValue(val, forKey: "inputTransform")

Swift 3更新：

let transform = CGAffineTransform.identity
let clampFilter = CIFilter(name: "CIAffineClamp")!
let val = NSValue(cgAffineTransform: transform)
clampFilter.setValue(val, forKey: "inputTransform")

Answer 2

這可能會。

var transform = CGAffineTransformIdentity;
var clampFilter = CIFilter(name: "CIAffineClamp")
var value = NSValue(CGAffineTransform: transform)
clampFilter.setValue(value, forKey: "inputTransform")