swift ViewControllerに直接図形を描画したい

Swift
1import UIKit
2
3class ViewController: UIViewController {
4
5    override func viewDidLoad() {
6        super.viewDidLoad()
7        
8        // 三角形 -------------------------------------
9        // UIBezierPath のインスタンス生成
10        let line = UIBezierPath();
11        // 起点
12        line.move(to: CGPoint(x: 50, y: 160));
13        // 帰着点
14        line.addLine(to: CGPoint(x: 200, y: 600));
15        line.addLine(to: CGPoint(x: 300, y: 280));
16        // ラインを結ぶ
17        line.close()
18        // 色の設定
19        UIColor.red.setStroke()
20        // ライン幅
21        line.lineWidth = 4
22        // 描画
23        line.stroke();
24    }
25    
26    override func didReceiveMemoryWarning() {
27        super.didReceiveMemoryWarning()
28        // Dispose of any resources that can be recreated.
29    }
30    
31}
32

実行エラーは以下の通りです

2018-06-06 17:10:00.063156+0900 UIBezierPathTest[401:270598] [Unknown process name] CGContextSetStrokeColorWithColor: invalid context 0x0. If you want to see the backtrace, please set CG_CONTEXT_SHOW_BACKTRACE environmental variable.
2018-06-06 17:10:00.063244+0900 UIBezierPathTest[401:270598] [Unknown process name] CGContextSaveGState: invalid context 0x0. If you want to see the backtrace, please set CG_CONTEXT_SHOW_BACKTRACE environmental variable.
2018-06-06 17:10:00.063273+0900 UIBezierPathTest[401:270598] [Unknown process name] CGContextSetLineWidth: invalid context 0x0. If you want to see the backtrace, please set CG_CONTEXT_SHOW_BACKTRACE environmental variable.
2018-06-06 17:10:00.063299+0900 UIBezierPathTest[401:270598] [Unknown process name] CGContextSetLineJoin: invalid context 0x0. If you want to see the backtrace, please set CG_CONTEXT_SHOW_BACKTRACE environmental variable.
2018-06-06 17:10:00.063350+0900 UIBezierPathTest[401:270598] [Unknown process name] CGContextSetLineCap: invalid context 0x0. If you want to see the backtrace, please set CG_CONTEXT_SHOW_BACKTRACE environmental variable.
2018-06-06 17:10:00.063391+0900 UIBezierPathTest[401:270598] [Unknown process name] CGContextSetMiterLimit: invalid context 0x0. If you want to see the backtrace, please set CG_CONTEXT_SHOW_BACKTRACE environmental variable.
2018-06-06 17:10:00.063418+0900 UIBezierPathTest[401:270598] [Unknown process name] CGContextSetFlatness: invalid context 0x0. If you want to see the backtrace, please set CG_CONTEXT_SHOW_BACKTRACE environmental variable.
2018-06-06 17:10:00.063462+0900 UIBezierPathTest[401:270598] [Unknown process name] CGContextAddPath: invalid context 0x0. If you want to see the backtrace, please set CG_CONTEXT_SHOW_BACKTRACE environmental variable.
2018-06-06 17:10:00.063488+0900 UIBezierPathTest[401:270598] [Unknown process name] CGContextDrawPath: invalid context 0x0. If you want to see the backtrace, please set CG_CONTEXT_SHOW_BACKTRACE environmental variable.
2018-06-06 17:10:00.063514+0900 UIBezierPathTest[401:270598] [Unknown process name] CGContextRestoreGState: invalid context 0x0. If you want to see the backtrace, please set CG_CONTEXT_SHOW_BACKTRACE environmental variable.

普段は、外側にUIViewクラスとして別に作って呼びます

Swift
1        // Screen Size の取得
2        let screenWidth = self.view.bounds.width
3        let screenHeight = self.view.bounds.height
4        
5        let testDraw = TestDraw(frame: CGRect(x: 0, y: 0,
6                                              width: screenWidth, height: screenHeight))
7        self.view.addSubview(testDraw)
8        
9    }
10

こちらでは、エラーを起こさすに動きます。
UIViewControllerに直接描画することはできないでしょうか？
参考にしている資料はこれです
資料

fuzzball

2018/06/06 09:05

ViewControllerのself.viewに描画したいということでしょうか？

L85A2

2018/06/06 09:48

そうです

行動規範の内容に同意します

回答1件

ベストアンサー

UIViewControllerのviewを描画したViewに置き換えるのはいかがでしょうか？

swift
1
2import UIKit
3
4class ViewController: UIViewController {
5    
6    override func loadView() {
7        
8        view = CustomView()
9        view.backgroundColor = .white
10    }
11
12    override func viewDidLoad() {
13        super.viewDidLoad()
14        
15    }
16}
17
18
19class CustomView: UIView {
20    
21    override func draw(_ rect: CGRect) {
22        
23        // 三角形 -------------------------------------
24        // UIBezierPath のインスタンス生成
25        let line = UIBezierPath();
26        // 起点
27        line.move(to: CGPoint(x: 50, y: 160));
28        // 帰着点
29        line.addLine(to: CGPoint(x: 200, y: 600));
30        line.addLine(to: CGPoint(x: 300, y: 280));
31        // ラインを結ぶ
32        line.close()
33        // 色の設定
34        UIColor.red.setStroke()
35        // ライン幅
36        line.lineWidth = 4
37        // 描画
38        line.stroke();
39    }
40}