EXC_BAD_ACCESS in my code - ios

Question

Can be bad access from this part of code?
I'm trying to draw graph.And in my function i have BAD_ACCESS.I can't find what is wrong.
- (void)drawPlot:(SHPlot *)plot {
NSDictionary *theme = plot.plotThemeAttributes;
CAShapeLayer *backgroundLayer = [CAShapeLayer layer];
backgroundLayer.frame = self.bounds;
backgroundLayer.fillColor = ((UIColor *)theme[kPlotFillColorKey]).CGColor;
backgroundLayer.backgroundColor = [UIColor clearColor].CGColor;
[backgroundLayer setStrokeColor:[UIColor clearColor].CGColor];
[backgroundLayer setLineWidth:((NSNumber *)theme[kPlotStrokeWidthKey]).intValue];
CGMutablePathRef backgroundPath = CGPathCreateMutable();
CAShapeLayer *circleLayer = [CAShapeLayer layer];
UIBezierPath *circle = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(0, 0, 75, 75)];
circleLayer.path = circle.CGPath;
circleLayer.strokeColor = [UIColor orangeColor].CGColor;
circleLayer.fillColor = [UIColor whiteColor].CGColor;
circleLayer.shadowColor =[UIColor blackColor].CGColor;
circleLayer.lineWidth = 3.0;
[self.layer addSublayer:circleLayer];
CGMutablePathRef circlePath = CGPathCreateMutable();
CAShapeLayer *graphLayer = [CAShapeLayer layer];
graphLayer.frame = self.bounds;
graphLayer.fillColor = [UIColor clearColor].CGColor;
graphLayer.backgroundColor = [UIColor clearColor].CGColor;
[graphLayer setStrokeColor:((UIColor *)theme[kPlotStrokeColorKey]).CGColor];
[graphLayer setLineWidth:((NSNumber *)theme[kPlotStrokeWidthKey]).intValue];
CGMutablePathRef graphPath = CGPathCreateMutable();
double yRange = [_yAxisRange doubleValue];
double yIntervalValue = yRange / INTERVAL_COUNT;
[plot.plottingValues enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
NSDictionary *dic = (NSDictionary *)obj;
[dic enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
int xIndex = [self getIndexForValue:key forPlot:plot];
double height = self.bounds.size.height - BOTTOM_MARGIN_TO_LEAVE;
double y = height - ((height / ([_yAxisRange doubleValue] + yIntervalValue)) * [obj doubleValue]);
(plot.xPoints[xIndex]).x = ceil((plot.xPoints[xIndex]).x);
(plot.xPoints[xIndex]).y = ceil(y);
}];
}];
CGPathMoveToPoint(graphPath, NULL, _leftMarginToLeave, plot.xPoints[0].y);
CGPathMoveToPoint(backgroundPath, NULL, _leftMarginToLeave, plot.xPoints[0].y);
int count = _xAxisValues.count;
for(int i=0; i< count; i++){
CGPoint point = plot.xPoints[i];
CGPathAddLineToPoint(graphPath, NULL, point.x, point.y);
CGPathAddLineToPoint(backgroundPath, NULL, point.x, point.y);
CGPathAddEllipseInRect(circlePath, NULL, CGRectMake(point.x - 5, point.y - 5, 10, 10));
}
CGPathAddLineToPoint(backgroundPath, NULL, _leftMarginToLeave + PLOT_WIDTH, self.bounds.size.height - BOTTOM_MARGIN_TO_LEAVE);
CGPathAddLineToPoint(backgroundPath, NULL, _leftMarginToLeave, self.bounds.size.height - BOTTOM_MARGIN_TO_LEAVE);
CGPathCloseSubpath(backgroundPath);
backgroundLayer.path = backgroundPath;
graphLayer.path = graphPath;
circleLayer.path = circlePath;
CGPathRelease(backgroundPath);
CGPathRelease(circlePath);
CGPathRelease(graphPath);
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:#"strokeEnd"];
animation.duration = 1;
animation.fromValue = #(0.0);
animation.toValue = #(1.0);
[graphLayer addAnimation:animation forKey:#"strokeEnd"];
backgroundLayer.zPosition = 0;
graphLayer.zPosition = 1;
circleLayer.zPosition = 2;
[self.layer addSublayer:graphLayer];
[self.layer addSublayer:circleLayer];
[self.layer addSublayer:backgroundLayer];
NSUInteger count2 = _xAxisValues.count;
for(int i=0; i< count2; i++){
CGPoint point = plot.xPoints[i];
UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];
btn.backgroundColor = [UIColor clearColor];
btn.tag = i;
btn.frame = CGRectMake(point.x - 10, point.y - 10, 40, 40);
[btn addTarget:self action:#selector(clicked:) forControlEvents:UIControlEventTouchUpInside];
//objc_setAssociatedObject(btn, kAssociatedPlotObject, plot, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
[self addSubview:btn];
}
circleLayer = nil;
graphLayer = nil;
backgroundLayer = nil;
}
This is my full function I have bad access in line [self addSubview:btn];

Answer 1

Move your code into the enumerate block
[plot.plottingValues enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
NSDictionary *dic = (NSDictionary *)obj;
[dic enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
int xIndex = [self getIndexForValue:key forPlot:plot];
double height = self.bounds.size.height - BOTTOM_MARGIN_TO_LEAVE;
double y = height - ((height / ([_yAxisRange doubleValue] + yIntervalValue)) * [obj doubleValue]);
(plot.xPoints[xIndex]).x = ceil((plot.xPoints[xIndex]).x);
(plot.xPoints[xIndex]).y = ceil(y);
}];
}];