iPhone LineChart

#define AXIS_Y_ITEM_COUNT 5 #define AXIS_X_ITEM_COUNT 5 NSMutableArray* radom_data() { srand((unsigned)time(NULL)); float base = 30; NSMutableArray *array = [[NSMutableArray alloc] init]; for (int i = 0; i < 100; i++) { NSLog(@"%f", (rand() % 1000) / 100.f + base); [array addObject:[NSNumber numberWithFloat:((rand() % 1000) / 100.f + base)]]; } return array; } float _max(NSArray *data) { float max = [[data objectAtIndex:0] floatValue]; for(NSNumber* num in data) { max = [num floatValue] > max ? [num floatValue] : max; } return max; } float _min(NSArray *data) { float min = [[data objectAtIndex:0] floatValue]; for(NSNumber* num in data) { min = [num floatValue] < min ? [num floatValue] : min; } return min; } - (id)initWithFrame:(CGRect)frame { if ((self = [super initWithFrame:frame])) { viewFrame = frame; } return self; } - (void)drawRect:(CGRect)rect { NSLog(@"######################## %f %f", viewFrame.size.width, viewFrame.size.height); NSNumberFormatter *numberFormatter = [NSNumberFormatter new]; [numberFormatter setNumberStyle:NSNumberFormatterDecimalStyle]; [numberFormatter setMinimumFractionDigits:2]; [numberFormatter setMaximumFractionDigits:2]; NSMutableArray* data = radom_data(); float max = _max(data); float min = _min(data); float offsetWidth = 80.0f; // 50 * 2 + 10 * 2 float offsetHeight = 60.0f; // 20 * 2 + 10 * 2 float stepY = (max - min) / AXIS_Y_ITEM_COUNT; float axisY_step = (viewFrame.size.height - offsetHeight) / (max - min); CGContextRef context = UIGraphicsGetCurrentContext(); CGContextClearRect(context, rect); for (int i = 0; i < AXIS_Y_ITEM_COUNT + 1; i++) { CGFloat lineDash[2]; lineDash[0] = 10.0f; lineDash[1] = 15.0f; CGContextSetLineDash(context, 0.0f, lineDash, 2); CGContextSetLineWidth(context, 0.6f); CGPoint sPoint = CGPointMake(offsetWidth / 2, viewFrame.size.height - (offsetHeight / 2) - i * stepY * axisY_step); CGPoint ePoint = CGPointMake(viewFrame.size.width - offsetWidth / 2, viewFrame.size.height - (offsetHeight / 2) - i * stepY * axisY_step); CGContextMoveToPoint(context, sPoint.x, sPoint.y); CGContextAddLineToPoint(context, ePoint.x, ePoint.y); CGContextClosePath(context); CGContextSetStrokeColorWithColor(context, [UIColor whiteColor].CGColor); CGContextStrokePath(context); UIFont *axisFont = [UIFont systemFontOfSize:[UIFont smallSystemFontSize]]; NSNumber *axisValue = [NSNumber numberWithFloat:(min + i * stepY)]; CGRect axisRect = CGRectMake(0.0f, sPoint.y - axisFont.capHeight, 50.0f, 20.0f); //CGRect axisRect = CGRectMake(0.0f, sPoint.y, 50.0f, 20.0f); [[UIColor redColor] set]; NSLog(@"%@", [numberFormatter stringForObjectValue:axisFont]); [[numberFormatter stringForObjectValue:axisValue] drawInRect:axisRect withFont:axisFont lineBreakMode:UILineBreakModeTailTruncation alignment:UITextAlignmentLeft]; } float stepX = 100 / AXIS_X_ITEM_COUNT; float axisX_step = (viewFrame.size.width - offsetWidth) / 100; CGContextSetLineDash(context, 0.0f, NULL, 0); for(int i = 0; i < AXIS_X_ITEM_COUNT + 1; i++) { CGPoint sPoint = CGPointMake(offsetWidth / 2 + i * stepX * axisX_step, viewFrame.size.height - offsetHeight / 2); CGContextMoveToPoint(context, sPoint.x, viewFrame.size.height - offsetHeight / 2); CGContextAddLineToPoint(context, sPoint.x, viewFrame.size.height - offsetHeight / 2 + 10); CGContextClosePath(context); CGContextSetStrokeColorWithColor(context, [UIColor redColor].CGColor); CGContextStrokePath(context); CGRect axisRect = CGRectMake(sPoint.x - 50 / 2, viewFrame.size.height - 20, 50.0f, 20.0f); UIFont *axisFont = [UIFont systemFontOfSize:[UIFont smallSystemFontSize]]; NSNumber *axisValue = [NSNumber numberWithInt:(i * stepX)]; NSLog(@"%f %f %@", axisRect.origin.x, axisRect.origin.y, [axisValue stringValue]); [[UIColor yellowColor] set]; [[axisValue stringValue] drawInRect:axisRect withFont:axisFont lineBreakMode:UILineBreakModeTailTruncation alignment:UITextAlignmentCenter]; } /* CGContextSetLineDash(context, 0.0f, NULL, 0); CGContextMoveToPoint(context, offsetWidth / 2, 0.0); CGContextAddLineToPoint(context, offsetWidth / 2, viewFrame.size.height - offsetHeight / 2 + 10); CGContextClosePath(context); CGContextSetStrokeColorWithColor(context, [UIColor whiteColor].CGColor); CGContextStrokePath(context); */ int _x = 0; for (NSNumber *number in data) { float value = [number floatValue]; CGPoint point = CGPointMake(_x++ * axisX_step + offsetWidth / 2, viewFrame.size.height - offsetHeight / 2 - (value - min) * axisY_step); if(_x == 1) { CGContextMoveToPoint(context, point.x, point.y); } else { CGContextAddLineToPoint(context, point.x, point.y); } } //CGContextSetLineCap(context, kCGLineCapRound); //CGContextSetLineJoin(context, kCGLineJoinRound); CGContextSetStrokeColorWithColor(context, [UIColor cyanColor].CGColor); CGContextStrokePath(context); } - (void)dealloc { [super dealloc]; }