我正在尝试在一个小框架中为正弦波设置动画,我在 SO 和网络上进行了很多搜索,但我能够达到的唯一目标是绘制一个从一侧转换到另一侧的静态正弦波,但不想要翻译我想要在帧中重复动画的正弦波的动画绘制。任何人都可以帮助我吗?这就是我现在要做的:
波.h
@interface Wave : UIView
@end
Wave.m
@implementation Wave
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// Initialization code
self.backgroundColor = [UIColor clearColor];
}
return self;
}
- (void)drawRect:(CGRect)rect
{
[[UIColor colorWithRed:0 green:192/255.0 blue:255/255.0 alpha:1] set];
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetLineWidth(context, 1);
CGContextSetLineJoin(context, kCGLineJoinRound);
float width = rect.size.width;
const CGFloat amplitude = 30 / 4;
for(CGFloat x = 0; x < width; x += 0.5)
{
CGFloat y = amplitude * sinf(2 * M_PI * (x / width) * 5) + 30;
if(x == 0)
CGContextMoveToPoint(context, x, y);
else
CGContextAddLineToPoint(context, x, y);
}
CGContextStrokePath(context);
}
然后在 UIViewController 我这样做:
- (void)viewDidLoad
{
self.wave = [[Wave alloc] initWithFrame:CGRectMake(self.view.frame.size.width/2-58, 205, 90, 200)];
[self.view addSubview:self.wave];
[self animateWave];
}
- (void)animateWave {
[UIView animateWithDuration:2.5 delay:0.0 options:UIViewAnimationOptionRepeat|UIViewAnimationOptionCurveLinear animations:^{
self.wave.transform = CGAffineTransformMakeTranslation(+self.wave.frame.size.width/2, 0);
} completion:^(BOOL finished) {
self.wave.transform = CGAffineTransformMakeTranslation(0, 0);
}];
}
但我不想要翻译,我想要连续绘制动画。
编辑:
我已经使用评论中的 CADisplayLink 建议编辑了我的问题:
// MainView.h
#import <UIKit/UIKit.h>
#import <QuartzCore/QuartzCore.h>
#import "AnimationLayer.h"
@interface MainView : UIView
{
AnimationLayer *alayer;
}
@end
// 主视图.m
#import "MainView.h"
@implementation MainView
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// Initialization code
[self setBackgroundColor:[UIColor clearColor]];
}
return self;
}
- (void)didMoveToSuperview
{
if ([self superview])
{
alayer = [[AnimationLayer alloc] init];
alayer.frame = self.frame;
[self.layer addSublayer:alayer];
}
}
@end
// AnimationLayer.h
#import <Foundation/Foundation.h>
#import <QuartzCore/QuartzCore.h>
@interface AnimationLayer : CALayer
{
CADisplayLink *displayLink;
}
@end
// 动画层.m
#import "AnimationLayer.h"
static bool _running;
@implementation AnimationLayer
- (id)init
{
self = [super init];
if (self)
{
displayLink = [CADisplayLink displayLinkWithTarget:self selector:@selector(setNeedsDisplay)];
[self setNeedsDisplayOnBoundsChange:YES];
}
return self;
}
static CGPoint lastPoint = {0, 0};
- (void)drawInContext:(CGContextRef)ctx
{
if (!_running)
{
[displayLink addToRunLoop:[NSRunLoop mainRunLoop] forMode:NSDefaultRunLoopMode];
_running = YES;
return;
}
CGContextSetStrokeColorWithColor(ctx, [[UIColor blackColor] CGColor]);
CGRect rect = CGContextGetClipBoundingBox(ctx);
CGContextSetLineWidth(ctx, 2);
CGContextSetLineJoin(ctx, kCGLineJoinRound);
float width = rect.size.width;
const CGFloat amplitude = 30 / 4;
CGContextMoveToPoint(ctx, lastPoint.x, lastPoint.y);
lastPoint.x += 0.5;
lastPoint.y = amplitude * sinf(2 * M_PI * (lastPoint.x / width) * 5) + 30;
CGContextAddLineToPoint(ctx, lastPoint.x, lastPoint.y);
CGContextStrokePath(ctx);
if (lastPoint.x == rect.size.width)
{
[displayLink invalidate];
_running = NO;
}
}
@end
并在uiviecontroller中以这种方式使用它:
MainView *view = [[MainView alloc] initWithFrame:CGRectMake(0, 0, 200, 200)];
[self.view addSubview:view];
现在我的问题是绘图代码只画了一个正弦波移动的小段,但没有画线,只有这个小段,这是我的所有代码,所以你可以尝试看看问题,我是如何可以修吗?