如何使此代碼更流暢。 我正在嘗試繪制三角形，並且一鍵（觸摸已移動）我想要調整其大小

Question

如何使此代碼更流暢。 我正在嘗試繪制三角形，並且一鍵（觸摸已移動）我想要調整其大小。 這是我的代碼：

-(id)initWithPoint:(CGPoint )point withFrame:(CGRect)frame{

    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code
        givenPoint = point;
    }
    return self;

    }

    - (void)drawRect:(CGRect)rect
    {
    // Drawing code

    CGContextRef ctx = UIGraphicsGetCurrentContext();
    CGContextSetRGBStrokeColor(ctx, 0, 0, 0, 1);


    CGPoint points[6] = { CGPointMake(10, 10), CGPointMake(50, 10),
        CGPointMake(50, 10), givenPoint,
        givenPoint, CGPointMake(10, 10) };
    CGContextSetRGBFillColor(ctx, 255, 255, 255, 1);
    CGContextStrokeLineSegments(ctx, points, 6);


    }

    -(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
    {
    UITouch *touch = [[event allTouches] anyObject];
    CGPoint location = [touch locationInView:touch.view];
    UIView *view = touch.view;

    [view removeFromSuperview];
    TailView *tailView = [[TailView alloc] initWithPoint:CGPointMake(location.x, location.y)  withFrame:CGRectMake(100, 100, location.x + 40, location.y + 40)];
    tailView.backgroundColor = [UIColor whiteColor];
    [self.view addSubview:tailView];

    UIPanGestureRecognizer *panRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(move:)];
    [panRecognizer setMinimumNumberOfTouches:1];
    [panRecognizer setMaximumNumberOfTouches:1];
    [panRecognizer setDelegate:self];
    [tailView addGestureRecognizer:panRecognizer];

}

Answer 1

簡而言之，drawRect很慢。 如果希望平滑，則應使用轉換。 不要將視圖從超級視圖中刪除並再次添加它，從而強制重繪，而應應用縮放和旋轉變換。