Question

我一直在研究，但没有找到答案。

如果我使用CGGontext将它绘制到视图中，是否可以从UIView中获取UIVezierPath（UIView）？（如果是的话，你能告诉我怎么做？）UIBezierPath来自用户输入，所以如果用户绘制了大量的UIBezierPath，我需要所有这些路径并将其保存到.svg文件中。

Answer 1

这是一个更好的工作示例，在测试了我在提交中给出的一些答案之后，这将是一个将根据您要查找的内容返回一个shapelayers或图层的数组：

CAShapeLayer * firstNameCorners = [CAShapeLayer layer];
[firstNameCorners setPath:[UIBezierPath bezierPathWithRoundedRect:CGRectMake(100, 100, 196.75, 44.0) byRoundingCorners:UIRectCornerBottomLeft|UIRectCornerTopLeft cornerRadii:(CGSize){2.5, 2.5}].CGPath];
[[self.view layer] addSublayer:firstNameCorners];

NSMutableArray *this = [[NSMutableArray alloc] init];

for (CALayer * rd in self.view.layer.sublayers) {
    if ([rd isKindOfClass:[CAShapeLayer class]]) {
        [this addObject:rd];
        NSLog(@"this is a layer: %@", rd);
    }
}
NSLog(@"this is an Array of Shapes: %@", this);

CAShapeLayer也可以只存储一行，无论该行有多复杂，如果它来自UIBezierPath，则该对象可以存储它，并将其存储在您正在绘制的UIView的子层中。事实上，为了进一步扩展这一点，为了您的目的，请参阅以下内容，这将返回CGPath，根据您的问题，这是您想要的：

CAShapeLayer * firstNameCorners = [CAShapeLayer layer];
[firstNameCorners setPath:[UIBezierPath bezierPathWithRoundedRect:CGRectMake(100, 100, 96.75, 44.0) byRoundingCorners:UIRectCornerBottomLeft|UIRectCornerTopLeft cornerRadii:(CGSize){2.5, 2.5}].CGPath];
[[self.view layer] addSublayer:firstNameCorners];

NSMutableArray *this = [[NSMutableArray alloc] init];

for (CALayer * rd in self.view.layer.sublayers) {
    if ([rd isKindOfClass:[CAShapeLayer class]]) {
        [this addObject:rd];
        CAShapeLayer * rf = (CAShapeLayer*)rd;
        NSLog(@"this is a layer: %@", rf.path);
        CGRect pathBounds = CGPathGetBoundingBox(rf.path);
        NSLog(@"this is this boundingBox: origin.X: %f, origin.X: %f, size.Width: %f, size.Height: %f", pathBounds.origin.x, pathBounds.origin.y, pathBounds.size.width, pathBounds.size.height);
    }
}
NSLog(@"this is an Array of Shapes: %@", this);

而且，如果你想更进一步，那么这可以存储CGRect坐标，而且，这将显示如何检索和使用这些坐标：

CAShapeLayer * firstNameCorners = [CAShapeLayer layer];
[firstNameCorners setPath:[UIBezierPath bezierPathWithRoundedRect:CGRectMake(100, 100, 196.75, 44.0) byRoundingCorners:UIRectCornerBottomLeft|UIRectCornerTopLeft cornerRadii:(CGSize){2.5, 2.5}].CGPath];
[[self.view layer] addSublayer:firstNameCorners];

NSMutableArray *this = [[NSMutableArray alloc] init];

NSMutableArray *that = [[NSMutableArray alloc] init];

for (CALayer * rd in self.view.layer.sublayers) {
    if ([rd isKindOfClass:[CAShapeLayer class]]) {
        [this addObject:rd];
        CAShapeLayer * rf = (CAShapeLayer*)rd;
        NSLog(@"this is a layer: %@", rf.path);
        CGRect pathBounds = CGPathGetBoundingBox(rf.path);
        [that addObject:[NSValue valueWithCGRect:pathBounds]];
        NSLog(@"this is this boundingBox: origin.X: %f, origin.X: %f, size.Width: %f, size.Height: %f", pathBounds.origin.x, pathBounds.origin.y, pathBounds.size.width, pathBounds.size.height);
    }
}

现在，完成，这是https://github.com/erica/iOS-6-Cookbook的改编，这是为了展示我开始绘制UIBezierPath的完全解读：

#define VALUE(_INDEX_) [NSValue valueWithCGPoint:points[_INDEX_]]

-(void)showPaths
{
    CAShapeLayer * firstNameCorners = [CAShapeLayer layer];
    [firstNameCorners setPath:[UIBezierPath bezierPathWithRoundedRect:CGRectMake(100, 100, 196.75, 44.0) byRoundingCorners:UIRectCornerBottomLeft|UIRectCornerTopLeft cornerRadii:(CGSize){2.5, 2.5}].CGPath];
    [[self.view layer] addSublayer:firstNameCorners];

    NSMutableArray *this = [[NSMutableArray alloc] init];

    NSMutableArray *that = [[NSMutableArray alloc] init];

    for (CALayer * rd in self.view.layer.sublayers) {
        if ([rd isKindOfClass:[CAShapeLayer class]]) {
            [this addObject:rd];
            CAShapeLayer * rf = (CAShapeLayer*)rd;
            NSLog(@"this is a layer: %@", rf.path);
            CGRect pathBounds = CGPathGetBoundingBox(rf.path);
            [that addObject:[NSValue valueWithCGRect:pathBounds]];

            CGMutablePathRef p3 = CGPathCreateMutableCopy(rf.path);
            NSArray *p3points = [self pointsFromCGPath:p3];
            for (NSValue *point in p3points) {
                NSLog(@"path element in p3: %@", NSStringFromCGPoint(point.CGPointValue));
            }
            NSLog(@"this is this boundingBox: origin.X: %f, origin.X: %f, size.Width: %f, size.Height: %f", pathBounds.origin.x, pathBounds.origin.y, pathBounds.size.width, pathBounds.size.height);
        }
    }
}

void getPointsFromBezier(void *info, const CGPathElement *element)
{
    NSMutableArray *bezierPoints = (__bridge NSMutableArray *)info;

    // Retrieve the path element type and its points
    CGPathElementType type = element->type;
    CGPoint *points = element->points;

    switch (type) {
        case kCGPathElementMoveToPoint:
            NSLog(@"MoveToPoint (%3.2f, %3.2f", points->x, points->y);
            break;
        case kCGPathElementAddLineToPoint:
            NSLog(@"AddLineToPoint (%3.2f, %3.2f)", points->x, points->y);
            break;
        case kCGPathElementAddQuadCurveToPoint:
            NSLog(@"AddQuadCurveToPoint (%3.2f, %3.2f), (%3.2f, %3.2f)", points->x, points->y, points[1].x, points[1].y);
            break;
        case kCGPathElementAddCurveToPoint:
            NSLog(@"AddCurveToPoint (%3.2f, %3.2f), (%3.2f, %3.2f), (%3.2f, %3.2f)", points->x, points->y, points[1].x, points[1].y, points[2].x, points[2].y);
            break;
        case kCGPathElementCloseSubpath:
            NSLog(@"CloseSubpath (%3.2f, %3.2f)", points->x, points->y);
            break;
        default:
            NSLog(@"unknown");
            break;
    }

    // Add the points if they're available (per type)
    if (type != kCGPathElementCloseSubpath)
    {
        [bezierPoints addObject:VALUE(0)];
        if ((type != kCGPathElementAddLineToPoint) &&
            (type != kCGPathElementMoveToPoint))
            [bezierPoints addObject:VALUE(1)];
    }
    if (type == kCGPathElementAddCurveToPoint)
        [bezierPoints addObject:VALUE(2)];
}

- (NSArray *)pointsFromCGPath:(CGPathRef)path
{
    NSMutableArray *points = [NSMutableArray array];
    CGPathApply(path, (__bridge void *)points, getPointsFromBezier);
    return points;
}

输出将记录到控制台，我们开始使用的所有路径都存储在CAShapeLayer中，输出太大而且很麻烦，不能在这里发布，但是这里的开头是这样的：

[30146：2680987] MoveToPoint（103.82,100.00

[30146：2680987] AddLineToPoint（296.75,100.00）

[30146：2680987] AddLineToPoint（296.75,144.00）

[30146：2680987] AddLineToPoint（103.82,144.00）

[30146：2680987] AddCurveToPoint（102.72,144.00），（102.17,144.00），   （101.67,143.84）

[30146：2680987] AddLineToPoint（101.58,143.81）

[30146：2680987] AddCurveToPoint（100.93,143.58），（100.42,143.07），   （100.19,142.42）

[30146：2680987] AddCurveToPoint（100.00,141.83），（100.00,141.28），   （100.00,140.18）

[30146：2680987] AddLineToPoint（100.00,103.82）

[30146：2680987] AddCurveToPoint（100.00,102.72），（100.00,102.17），   （100.16,101.67）

[30146：2680987] AddLineToPoint（100.19,101.58）

[30146：2680987] AddCurveToPoint（100.42,100.93），（100.93,100.42），   （101.58,100.19）

[30146：2680987] AddCurveToPoint（102.17,100.00），（102.72,100.00），   （103.82,100.00）

[30146：2680987] AddLineToPoint（103.82,100.00）

[30146：2680987] p3中的路径元素：{103.8216625,100}

[30146：2680987] p3中的路径元素：{296.75,100}

[30146：2680987] p3中的路径元素：{296.75,144}

[30146：2680987] p3中的路径元素：{103.8216625,144}

[30146：2680987] p3中的路径元素：{102.72123239404632,144}

[30146：2680987] p3中的路径元素：{102.17101736015751,144}

Answer 2

如果您正在使用Core Graphics绘制路径，那么您可能有一些模型支持drawRect利用的视图以绘制所有路径。如果你不这样做（即你只是更新位图），你应该简单地重构该代码以捕获并保存表示路径所需的信息。

是否可以从uiview获取所有uibezerpath？

2 个答案: