7

我正在尝试通过以下方式为线条的绘制设置动画：

。H

CAShapeLayer *rootLayer;
CAShapeLayer *lineLayer;
CGMutablePathRef path;

.m

 path = CGPathCreateMutable();
 CGPathMoveToPoint(path, nil, self.frame.size.width/2-100, 260);
 CGPathAddLineToPoint(path, nil, self.frame.size.width/2+100.0, 260);    
 CGPathCloseSubpath(path);

 self.rootLayer = [CALayer layer];
 rootLayer.frame = self.bounds;
[self.layer addSublayer:rootLayer];

 self.lineLayer = [CAShapeLayer layer];
[lineLayer setPath:path];
[lineLayer setFillColor:[UIColor redColor].CGColor];
[lineLayer setStrokeColor:[UIColor blueColor].CGColor];
[lineLayer setLineWidth:1.5];
[lineLayer setFillRule:kCAFillRuleNonZero];
[rootLayer addSublayer:lineLayer];

[self performSelector:@selector(startTotalLine) withObject:nil afterDelay:1.5];

- (void)startTotalLine
{    
      CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"animatePath"];
      [animation setDuration:3.5];
       animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
      [animation setAutoreverses:NO];
      [animation setFromValue:(id)path];
      [animation setToValue:(id)path];
      [lineLayer addAnimation:animation forKey:@"animatePath"];    
}

startTotalLine在调用方法之前绘制的线。此外，该startTotalLine方法不会影响线路。

我希望它从右到左为线条图设置动画。

4

3 回答 3

6

我会用动画属性来做。

为了实现这一点，我将创建一个自定义CALayer类 - 我们称之为LineLayer。定义一个startPoint属性，一个length属性。然后我将length属性配置为“动画”。

代码如下所示：

// LineLayer.h
@interface LineLayer: CALayer

@property (nonatomic, assign) int length;
// This was omitted from the SO code snippet.
@property (nonatomic, assign) CGPoint startPoint;

@end

// LineLayer.m
@implementation LineLayer

@synthesize length = _length;
// This was omitted from the SO code snippet.
@synthesize startPoint= _startPoint;

- (id) initWithLayer:(id)layer 
{
    if(self = [super initWithLayer:layer]) 
    {
        if([layer isKindOfClass:[LineLayer class]]) 
        {
            // This bit is required for when we CA is interpolating the values.
            LineLayer *other = (LineLayer*)layer;
            self.length = other.length;
            self.startPoint = other.startPoint; // This was omitted.
        }
    }
    return self;
}

+ (BOOL)needsDisplayForKey:(NSString *)key 
{
    if ([key isEqualToString:@"length"]) {
        return YES;
    }
    return [super needsDisplayForKey:key];
}

- (void) setLength:(int)newLength
{
    if (newLength < 0) {
        return; // Fail early.
    }
    _length = newLength; 
    [self setNeedsDisplay]; 
} 

/*
    This should have been drawInContext:(CGContextRef)context
    - (void) drawRect:(CGRect) rect 
*/
- (void) drawInContext:(CGContextRef)context
{
    //...Do your regular drawing here.

    // This was omitted from the SO code snippet.
    CGContextSetStrokeColorWithColor(context, [UIColor redColor].CGColor);
    CGContextSetLineWidth(context, 2);
    CGContextMoveToPoint(context, _startPoint.x, _startPoint.y);
    CGContextAddLineToPoint(context, _startPoint.x + _length, _startPoint.y);
    CGContextStrokePath(context);
}

@end

然后在您的视图控制器中，您可以LineLayer像这样使用：

- (void)viewDidLoad
{
    [super viewDidLoad];

    LineLayer *lineLayer = [LineLayer new];

    // This was omitted from the SO code snippet.
    lineLayer.frame = CGRectMake(0, 0, 320, 480);
    [lineLayer setNeedsDisplay];
    // ---

    lineLayer.startPoint = CGPointMake(0, 100);
    lineLayer.length = 0;

    [self.view.layer addSublayer:lineLayer];

    // Now animate the changes to the length property
    CABasicAnimation *anim = [CABasicAnimation animationWithKeyPath:@"length"];
    anim.duration = 5; // Change should table about 5 mins.
    anim.fromValue = [NSNumber numberWithInt:0];
    anim.toValue = [NSNumber numberWithInt:200];

    [lineLayer addAnimation:anim forKey:@"animateLength"];
    lineLayer.length = 200;
    //Do clean up below...
}

快乐编码:)

于 2012-05-15T18:54:59.890 回答
4

我认为做你想做的最简单的方法是呈现一些 1.5 像素高度的 UIView 并为其宽度设置动画。问我是否不清楚。

我认为您的代码不起作用，因为您的变量path不是图层属性。阅读手册：

CABasicAnimation 为图层属性提供基本的单关键帧动画功能。

你在这里做了一些奇怪的事情：

[animation setFromValue:(id)path];
[animation setToValue:(id)path];

编辑：我偶然发现了一篇文章，并了解您要达到的目标！现在我认为你失败的原因是你可以为不改变点数的路径设置动画。现在我想你可以用两点创建一条路径线。起初它们在同一个地方，另一条路径是你想要结束的那条线。现在从第一条路径动画到第二条。我认为它应该工作，但我不确定。

编辑：绝对！你需要这个人的代码。吉特链接。

于 2012-05-15T15:19:48.153 回答
1

这是我使用“UIBezierPath”、“CAShapeLayer”和属性“strokeEnd”针对您的情况的解决方案：

.m 文件

@synthesize shapeLayer;
[self drawLine];

-(void)drawLine {
    CGFloat X1 = self.frame.size.width/2-100;
    CGFloat Y1 = 260;
    CGFloat X2 = self.frame.size.width/2+100.0;
    CGFloat Y2 = 260;

    UIBezierPath *path = [UIBezierPath bezierPath];
    [path moveToPoint:CGPointMake(X1, Y1)];
    [path addLineToPoint:CGPointMake(X2, Y2)];

    CAShapeLayer *shapeLayer = [CAShapeLayer layer];
    shapeLayer.path = [path CGPath];
    shapeLayer.strokeColor = [[UIColor blueColor] CGColor];
    shapeLayer.lineWidth = 1.5;
    shapeLayer.fillColor = [[UIColor redColor] CGColor];
    shapeLayer.strokeEnd =0;

    [self.layer addSublayer:shapeLayer];
    [self performSelector:@selector(startTotalLine) withObject:nil afterDelay:1.5];
}

- (void)startTotalLine {   
    CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"strokeEnd"];
    animation.duration = 3.5f;
    animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
    [animation setAutoreverses:NO];
    [animation setFromValue:[NSNumber numberWithInt:0]];
    [animation setToValue:[NSNumber numberWithInt:1]];
    [shapeLayer addAnimation:animation forKey:@"animatePath"];
}

默认的“strokeEnd”值为1，因此，在开头设为0（不会出现线条）。顺便说一句，这里提供了有用的例子：http: //jamesonquave.com/blog/fun-with-cashapelayer/

于 2015-07-04T01:43:34.417 回答