前言
当写完了所有需要使用的素材类后，我们开始搭建一个比较完整的K线Demo。
它包含以下功能：
1、可以展示蜡烛图
2、可以展示OHLC图
3、可以左右滑动
4、可以长按出现十字叉
5、有基本的价格和日期区间展示
GO
在上几篇文章中，我们已经知道如何绘制蜡烛、边框、OHLC等。所以在这里，可以直接使用已经写好的类。
绘制边框
首页，我们先绘制一个包含主副图的边框：
/**
绘制边框
*/
- (void)drawBorder
{
//设置主图、主图指标、副图、副图指标rect
_mainIndexRect = CGRectMake(0, 0, CGRectGetWidth(self.frame), mainIndexH);
_mainRect = CGRectMake(0, mainIndexH, CGRectGetWidth(self.frame), (CGRectGetHeight(self.frame) - (mainIndexH + accessoryIndexH + dateH)) * mainFrameScale);
_accessoryIndexRect = CGRectMake(0, mainIndexH + CGRectGetHeight(_mainRect)+dateH, CGRectGetWidth(self.frame), accessoryIndexH);
_accessoryRect = CGRectMake(0, mainIndexH + CGRectGetHeight(_mainRect)+dateH+accessoryIndexH, CGRectGetWidth(self.frame), (CGRectGetHeight(self.frame) - (mainIndexH + accessoryIndexH + dateH)) * (1-mainFrameScale));
CAShapeLayer *borderLayer = [CAShapeLayer layer];
UIBezierPath *path = [UIBezierPath bezierPathWithRect:self.bounds];
[path moveToPoint:CGPointMake(0, mainIndexH)];
[path addLineToPoint:CGPointMake(CGRectGetWidth(self.frame), mainIndexH)];
[path moveToPoint:CGPointMake(0, CGRectGetMaxY(_mainRect))];
[path addLineToPoint:CGPointMake(CGRectGetWidth(self.frame), CGRectGetMaxY(_mainRect))];
[path moveToPoint:CGPointMake(0, CGRectGetMinY(_accessoryIndexRect))];
[path addLineToPoint:CGPointMake(CGRectGetWidth(self.frame), CGRectGetMinY(_accessoryIndexRect))];
[path moveToPoint:CGPointMake(0, CGRectGetMinY(_accessoryRect))];
[path addLineToPoint:CGPointMake(CGRectGetWidth(self.frame), CGRectGetMinY(_accessoryRect))];
float mainUnitH = CGRectGetHeight(_mainRect) / 4.f;
float mainUnitW = CGRectGetWidth(_mainRect) / 4.f;
for (int idx = 1; idx <= 3; idx++)
{
//画3条横线
[path moveToPoint:CGPointMake(0, mainIndexH + mainUnitH * idx)];
[path addLineToPoint:CGPointMake(CGRectGetWidth(self.frame), mainIndexH + mainUnitH * idx)];
//画3条竖线
[path moveToPoint:CGPointMake(idx * mainUnitW, mainIndexH)];
[path addLineToPoint:CGPointMake(idx * mainUnitW, CGRectGetMaxY(_mainRect))];
//画3条竖线
[path moveToPoint:CGPointMake(idx * mainUnitW, CGRectGetMinY(_accessoryRect))];
[path addLineToPoint:CGPointMake(idx * mainUnitW, CGRectGetMaxY(_accessoryRect))];
}
float accessoryUnitH = CGRectGetHeight(_accessoryRect) / 2.f;
[path moveToPoint:CGPointMake(0, CGRectGetMaxY(_accessoryRect) - accessoryUnitH)];
[path addLineToPoint:CGPointMake(CGRectGetWidth(self.frame), CGRectGetMaxY(_accessoryRect) - accessoryUnitH)];
borderLayer.path = path.CGPath;
borderLayer.lineWidth = 0.5f;
borderLayer.strokeColor = [UIColor colorWithRed:222.f/255.f green:222.f/255.f blue:222.f/255.f alpha:1.f].CGColor;
borderLayer.fillColor = [UIColor clearColor].CGColor;
[self.layer addSublayer:borderLayer];
}
效果如下：
边框
导入数据
边框绘制完以后，我们把k线数据转换为坐标点。在转换之前，还需要寻找当前在屏幕上展示数据的极限值，也就是最大最小值。
这里要注意，因为当前屏幕中一般最多显示60个左右的蜡烛数量，但是某一个周期K线的蜡烛数量一般是几百个，所以在K线数据转为模型数据后，需要有一个起始索引来标识当前展示的数据范围。
寻找极限值：
//求出最大最小值
_min = (float)INT32_MAX;
_max = (float)INT32_MIN;
for (int idx=_startIndex; idx<_endIndex; idx++)
{
YKKLineModel *model = self.kLineModelArr[idx];
if (_min > model.low)
{
_min = model.low;
}
if (_max < model.high)
{
_max = model.high;
}
}
把数据转换为坐标点：
[self.displayPointArr removeAllObjects];
//每根蜡烛的宽度
float candleW = CGRectGetWidth(_mainRect) / candleCount;
for (int idx = _startIndex; idx<_endIndex; idx++)
{
YKKLineModel *model = self.kLineModelArr[idx];
float x = CGRectGetMinX(_mainRect) + candleW * (idx - (_startIndex - 0));
CGPoint hPoint = CGPointMake(x + candleW/2,
ABS(CGRectGetMaxY(_mainRect) - (model.high - _min)/unitValue));
CGPoint lPoint = CGPointMake(x + candleW/2,
ABS(CGRectGetMaxY(_mainRect) - (model.low - _min)/unitValue));
CGPoint oPoint = CGPointMake(x + candleW/2,
ABS(CGRectGetMaxY(_mainRect) - (model.open - _min)/unitValue));
CGPoint cPoint = CGPointMake(x + candleW/2,
ABS(CGRectGetMaxY(_mainRect) - (model.close - _min)/unitValue));
[_displayPointArr addObject:[YKCandlePointModel candlePointModelWithOpoint:oPoint
Hpoint:hPoint
Lpoint:lPoint
Cpoint:cPoint]];
}
绘制蜡烛/OHLC
导入数据并且转换为坐标点以后，接下来开始绘制。
绘制蜡烛：
//每根蜡烛的宽度
float candleW = CGRectGetWidth(_mainRect) / candleCount;
for (int idx = 0; idx< candleCount; idx++)
{
YKCandlePointModel *model = pointModelArr[idx];
CAShapeLayer *layer = [CAShapeLayer getCandleLayerWithPointModel:model candleW:candleW];
[self.candleLayer addSublayer:layer];
}
[self.layer addSublayer:self.candleLayer];
绘制OHLC：
//每根OHLC的宽度
float candleW = CGRectGetWidth(_mainRect) / candleCount;
for (int idx = 0; idx< candleCount; idx++)
{
YKCandlePointModel *model = pointModelArr[idx];
CAShapeLayer *layer = [CAShapeLayer getOHLCLayerWithPointModel:model candleW:candleW];
[self.ohlcLayer addSublayer:layer];
}
[self.layer addSublayer:self.ohlcLayer];
效果如下：
蜡烛
OHLC
绘制价格、日期区间
蜡烛绘制完以后，我们还剩下价格、日期。价格是指左侧的5个价格的区间标识，从上往下降序排列；日期为下方5个日期的区间标识，每一个标识都是距离当前点最近的点的日期。
绘制左侧价格：
float unitPrice = (_max - _min) / 4.f;
float unitH = CGRectGetHeight(_mainRect) / 4.f;
//求得价格rect
NSDictionary *attribute = @{NSFontAttributeName:[UIFont systemFontOfSize:9.f]};
CGRect priceRect = [self rectOfNSString:[NSString stringWithFormat:@"%.2f", _max] attribute:attribute];
for (int idx = 0; idx < 5; idx++)
{
float height = 0.f;
if (idx == 4)
{
height = idx * unitH - CGRectGetHeight(priceRect);
} else
{
height = idx * unitH;
}
CGRect rect = CGRectMake(CGRectGetMinX(_mainRect),
CGRectGetMinY(_mainRect) + height,
CGRectGetWidth(priceRect),
CGRectGetHeight(priceRect));
//计算价格
NSString *str = [NSString stringWithFormat:@"%.2f", _max - idx * unitPrice];
CATextLayer *layer = [CATextLayer getTextLayerWithString:str
textColor:[UIColor blackColor]
fontSize:9.f
backgroundColor:[UIColor clearColor]
frame:rect];
[self.leftPriceLayer addSublayer:layer];
}
[self.layer addSublayer:self.leftPriceLayer];
绘制日期（这里要注意，因为使用的Demo数据周期为天，所以日期也具体到天）：
NSMutableArray *kLineDateArr = [NSMutableArray array];
int unitCount = candleCount / 4;
for (int idx=0; idx<5; idx++)
{
YKKLineModel *model = self.kLineModelArr[_startIndex + idx * unitCount];
NSDate *detaildate = [NSDate dateWithTimeIntervalSince1970:model.timeStamp];
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"YYYY-MM-dd"];
NSString *dateStr = [dateFormatter stringFromDate:detaildate];
[kLineDateArr addObject:dateStr];
}
NSDictionary *attribute = @{NSFontAttributeName:[UIFont systemFontOfSize:9.f]};
CGRect strRect = [self rectOfNSString:@"0000-00-00" attribute:attribute];
float strW = CGRectGetWidth(strRect);
float strH = CGRectGetHeight(strRect);
float unitW = CGRectGetWidth(_mainRect) / 4;
//循环绘制坐标点
for (int idx = 0; idx < kLineDateArr.count; idx++)
{
CATextLayer *textLayer = nil;
if (idx == kLineDateArr.count-1)
{//最后一个
CGRect rect = CGRectMake(idx * unitW - strW, CGRectGetMaxY(_mainRect), strW, strH);
textLayer = [CATextLayer getTextLayerWithString:kLineDateArr[idx] textColor:[UIColor blackColor] fontSize:9.f backgroundColor:[UIColor clearColor] frame:rect];
}else if(idx == 0)
{//第一个
CGRect rect = CGRectMake(idx * unitW, CGRectGetMaxY(_mainRect), strW, strH);
textLayer = [CATextLayer getTextLayerWithString:kLineDateArr[idx] textColor:[UIColor blackColor] fontSize:9.f backgroundColor:[UIColor clearColor] frame:rect];
}else
{//中间
CGRect rect = CGRectMake(idx * unitW - strW/2, CGRectGetMaxY(_mainRect), strW, strH);
textLayer = [CATextLayer getTextLayerWithString:kLineDateArr[idx] textColor:[UIColor blackColor] fontSize:9.f backgroundColor:[UIColor clearColor] frame:rect];
}
[self.bottomDateLayer addSublayer:textLayer];
}
[self.layer addSublayer:self.bottomDateLayer];
效果如下：
区间标识
添加左右滑动
在以前我们讨论过滑动偏移量的获取方式，这里就暂且通过添加手势来获取偏移量。使用长按手势来做十字叉效果，使用拖动手势来做左右滑动效果。
当检测到用户长按时，获取坐标点然后转换为柱子索引，再绘制十字叉，左侧和下侧展示当前索引的数据。当用户抬起手指时，可以选择及时清除掉十字叉，也可以加一个延时清除。
当检测到用户拖动时，用偏移量的正负来判断用户是向左还是向右拖动。每次检测到拖动后，获取到偏移量，因为这个偏移量不是太线性，所以添加一个范围的判断。拿到偏移量以后，再更新展示数据的起始索引值，然后再更新视图。
添加手势：
//添加左右拖动手势
UIPanGestureRecognizer *panG = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panGestureAction:)];
[_kLineView addGestureRecognizer:panG];
//添加长按手势
UILongPressGestureRecognizer *longG = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(kLineLongGestureAction:)];
longG.minimumPressDuration = 0.5f;
longG.numberOfTouchesRequired = 1;
[_kLineView addGestureRecognizer:longG];
响应手势：
/**
K线响应长按手势
@param longGesture 手势对象
*/
- (void)kLineLongGestureAction:(UILongPressGestureRecognizer *)longGesture
{
if (longGesture.state == UIGestureRecognizerStateBegan || longGesture.state == UIGestureRecognizerStateChanged)
{
CGPoint point = [longGesture locationInView:_kLineView];
float x = 0.f;
if (point.x < 0.f)
{
x = 0.f;
}else if (point.x > CGRectGetWidth(_kLineView.frame))
{
x = CGRectGetWidth(_kLineView.frame)-1;
}else
{
x = point.x;
}
//当长按滑动时，每滑动一次话会重新刷新十字叉
[_kLineView drawCrossViewWithX:x];
}else
{
//当手指抬起时，及时把十字叉取消掉
[_kLineView clearCrossViewLayer];
}
}
/**
响应拖动手势
@param panGesture 手势对象
*/
- (void)panGestureAction:(UIPanGestureRecognizer *)panGesture
{
CGPoint point = [panGesture translationInView:_kLineView];
float offset = point.x - kLineGlobalOffset;
if (panGesture.state == UIGestureRecognizerStateChanged && ABS(offset) > 3)
{
if (offset > 0)
{
if (ABS(offset) > 20)
{
[_kLineView dragRightOffsetcount:5];
} else if(ABS(offset) > 6)
{
[_kLineView dragRightOffsetcount:2];
} else
{
[_kLineView dragRightOffsetcount:1];
}
}else
{
if (ABS(offset) > 20)
{
[_kLineView dragLeftOffsetcount:5];
} else if(ABS(offset) > 6)
{
[_kLineView dragLeftOffsetcount:2];
} else
{
[_kLineView dragLeftOffsetcount:1];
}
}
kLineGlobalOffset = point.x;
}
if (panGesture.state == UIGestureRecognizerStateEnded ||
panGesture.state == UIGestureRecognizerStateCancelled ||
panGesture.state == UIGestureRecognizerStateFailed)
{
kLineGlobalOffset= 0.f;
}
}
效果如下：
OHLC线
Demo源码下载
至此，我们已经把K线主图大部分的功能搭建完毕。Demo源码点击这里下载。下篇文章，会说到主副图指标的一些事，敬请期待。
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