objective-c：drawRect - 路径绘制不完整

Question

我正在尝试画一个六边形，并且已经在网上关注了几个教程。但我必须做错事，因为我的结果总是不完整的。最初我认为这是因为我使视图框架太小，但即使我将w / h提高到800，我仍然得到相同的结果。这是我的代码：

FEG_Map是一个UIView，它在viewcontroller中设置并保存十六进制网格。

@implementation FEG_Map

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code
    }
    return self;
}

- (void) addHex {

    float rowX = 400.0;
    float rowY = 10.0;

        FEG_Hex* thisHex = [[FEG_Hex alloc] initWithFrame:CGRectMake(rowX, rowY, 800.0, 800.0)];
        thisHex.backgroundColor = [UIColor clearColor];
        [self addSubview:thisHex];

}

在FEG_Hex我骑过drawRect并添加：

- (void)drawRect:(CGRect)rect {


    //create mutable path
    CGMutablePathRef path = CGPathCreateMutable();

    //go to start point
    CGPathMoveToPoint(path, nil, _origin.x, _origin.y);

    //move along hex path
    CGPoint newloc = CGPointMake(_origin.x - 20, _origin.y + 42);
    CGPathMoveToPoint(path, NULL, newloc.x, newloc.y);
    CGPathAddLineToPoint(path, NULL, newloc.x + 16,newloc.y + 38);
    CGPathAddLineToPoint(path, NULL, newloc.x + 49, newloc.y + 0);
    CGPathAddLineToPoint(path, NULL, newloc.x + 23,  newloc.y - 39);
    CGPathAddLineToPoint(path, NULL, newloc.x - 25,newloc.y - 40);
    CGPathAddLineToPoint(path, NULL, newloc.x -43, newloc.y + 0);
    CGPathCloseSubpath(path);

    //add a context
    CGContextRef context = UIGraphicsGetCurrentContext();

    //add path to context
    CGContextAddPath(context, path);

    //stroke path
    CGContextSetLineWidth(context, 2.0);

    //set the stroke color
    CGContextSetStrokeColorWithColor(context, [UIColor blackColor].CGColor);

    CGContextStrokePath(context);




}

我的结果是：

Answer 1

更改您的代码：

CGPoint newloc = CGPointMake(_origin.x - 20, _origin.y + 42);

到

CGPoint newloc = CGPointMake(_origin.x + 42, _origin.y + 20);

你会看到你的六边形。但这不正确。

要获得更正确的六边形，请使用以下代码：

CGPoint newloc = CGPointMake(_origin.x + 46, _origin.y + 20);
CGPathMoveToPoint(path, NULL, newloc.x + 23, newloc.y + 40);
CGPathAddLineToPoint(path, NULL, newloc.x + 46, newloc.y + 0);
CGPathAddLineToPoint(path, NULL, newloc.x + 23, newloc.y - 40);
CGPathAddLineToPoint(path, NULL, newloc.x - 23, newloc.y - 40);
CGPathAddLineToPoint(path, NULL, newloc.x - 46, newloc.y + 0);
CGPathAddLineToPoint(path, NULL, newloc.x - 23, newloc.y + 40);
CGPathCloseSubpath(path);