我正在使用核心情节来制作实时图表。 这些值来自Web服务，但只提供了45个值，然后必须停止。 我得到了核心图1.4的实时图样本，它几乎正常工作。
我有两个问题，我的图形固定为0,0而我的y轴消失了。 该图正确地在值数组（轴X）处输入数据。 日期数组（轴Y）与值数组不同。 此外，在此之前，我让图表在没有动画的情况下工作。
到目前为止，这是我的代码，我相信所需要的只是：
#pragma mark - CPTPlotDataSource methods
-(NSUInteger)numberOfRecordsForPlot:(CPTPlot *)plot {
return [plotData count];
}
-(void)newData:(NSTimer *)theTimer
{
// CPTGraph *theGraph = [self.graphs objectAtIndex:0];
CPTPlot *thePlot = [self.hostView.hostedGraph plotWithIdentifier:CPDTickerSymbolGOOG];
if ( thePlot ) {
if ( plotData.count >= kMaxDataPoints ) {
[plotData removeObjectAtIndex:0];
[thePlot deleteDataInIndexRange:NSMakeRange(0, 1)];
[dataTimer invalidate];
return;
}
CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *)self.hostView.hostedGraph.defaultPlotSpace;
NSUInteger location = (currentIndex >= kMaxDataPoints ? currentIndex - kMaxDataPoints + 2 : 0);
CPTPlotRange *newRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromUnsignedInteger(location)
length:CPTDecimalFromUnsignedInteger(kMaxDataPoints - 2)];
[CPTAnimation animate:plotSpace
property:@"xRange"
fromPlotRange:plotSpace.xRange
toPlotRange:newRange
duration:(1.0 / kFrameRate)];
currentIndex++;
NSLog(@"%@",plotData);
[plotData addObject:[arrValues lastObject]];
[arrValues removeObjectAtIndex:[arrValues count] -1];
[thePlot insertDataAtIndex:plotData.count - 1 numberOfRecords:1];
}
}
-(NSNumber *)numberForPlot:(CPTPlot *)plot field:(NSUInteger)fieldEnum recordIndex:(NSUInteger)index {
NSInteger valueCount = [[self datesInMonth]count];
// switch (fieldEnum) {
// case CPTScatterPlotFieldX:
// if (index < valueCount) {
// return [NSNumber numberWithUnsignedInteger:index];
// }
// break;
//
// case CPTScatterPlotFieldY:
//
// if ([plot.identifier isEqual:CPDTickerSymbolAAPL] == YES) {
// return [[[CPDStockPriceStore sharedInstance] monthlyPrices:CPDTickerSymbolAAPL] objectAtIndex:index];
// } else if ([plot.identifier isEqual:CPDTickerSymbolGOOG] == YES) {
// return [[[CPDStockPriceStore sharedInstance] monthlyPrices:CPDTickerSymbolGOOG] objectAtIndex:index];
// } else if ([plot.identifier isEqual:CPDTickerSymbolMSFT] == YES) {
// return [[[CPDStockPriceStore sharedInstance] monthlyPrices:CPDTickerSymbolMSFT] objectAtIndex:index];
// }
// break;
// }
NSNumber *num = nil;
switch ( fieldEnum ) {
case CPTScatterPlotFieldX:
num = [NSNumber numberWithUnsignedInteger:index + currentIndex - plotData.count];
break;
case CPTScatterPlotFieldY:
num = [plotData objectAtIndex:index];
break;
default:
break;
}
return num;
return [NSDecimalNumber zero];
}
-(void)configureAxes {
// 1 - Create styles
CPTMutableTextStyle *axisTitleStyle = [CPTMutableTextStyle textStyle];
axisTitleStyle.color = [CPTColor whiteColor];
axisTitleStyle.fontName = @"Helvetica-Bold";
axisTitleStyle.fontSize = 16.0f;
CPTMutableTextStyle *axisTextStyle = [[CPTMutableTextStyle alloc] init];
axisTextStyle.fontName = @"Helvetica";
axisTextStyle.fontSize = 12.0f;
CPTMutableLineStyle *axisLineStyle = [CPTMutableLineStyle lineStyle];
axisLineStyle.lineWidth = 0.5f;
axisLineStyle.lineColor = [[CPTColor whiteColor] colorWithAlphaComponent:0.4];
CPTMutableLineStyle *tickLineStyle = [CPTMutableLineStyle lineStyle];
tickLineStyle.lineColor = [CPTColor whiteColor];
tickLineStyle.lineWidth = 0.0f;
CPTMutableLineStyle *majorGridLineStyle = [CPTMutableLineStyle lineStyle];
majorGridLineStyle.lineWidth = 1.0;
majorGridLineStyle.lineColor = [[CPTColor whiteColor] colorWithAlphaComponent:0.4];
CPTMutableLineStyle *minorGridLineStyle = [CPTMutableLineStyle lineStyle];
minorGridLineStyle.lineColor = [CPTColor whiteColor];
minorGridLineStyle.lineWidth = 1.0f;
// 2 - Get axis set
CPTXYAxisSet *axisSet = (CPTXYAxisSet *) self.hostView.hostedGraph.axisSet;
// 3 - Configure x-axis
CPTXYAxis *x = axisSet.xAxis;
x.orthogonalCoordinateDecimal = CPTDecimalFromInteger(0);
//x.title = @"Day of Month";
x.titleTextStyle = axisTitleStyle;
x.titleOffset = 15.0f;
x.axisLineStyle = axisLineStyle;
// x.majorGridLineStyle = majorGridLineStyle;
x.labelingPolicy = CPTAxisLabelingPolicyNone;
x.majorTickLineStyle = axisLineStyle;
x.majorTickLength = 30.0f;
x.tickDirection = CPTSignNegative;
//x.labelOffset = -25;
CGFloat dateCount = 1;
NSMutableSet *xLabels = [NSMutableSet setWithCapacity:dateCount];
NSMutableSet *xLocations = [NSMutableSet setWithCapacity:dateCount];
NSInteger i = 0;
// NSLog(@"datesInMonth - >%@",[self datesInMonth]);
NSArray *_weekDays = @[@"", @"D", @"S", @"T", @"Q", @"Q", @"S", @"S"];
int z = 0;
for (NSString *date in [self datesInMonth]) {
int contador = i++;
NSDateFormatter *df = [[NSDateFormatter alloc] init];
[df setDateFormat:@"dd/MM/yyyy"];
NSString *dateTimeString = [date stringByAppendingString:@"12:00:00"];
const char* dateString = [dateTimeString UTF8String];
struct tm tm;
time_t timestamp;
strptime(dateString, "%d/%m/%Y %H:%M:%S", &tm);
timestamp = mktime(&tm);
NSDate *myDate = [NSDate dateWithTimeIntervalSince1970:timestamp];
NSDateComponents *components = [[NSCalendar currentCalendar] components:NSCalendarUnitDay |
NSCalendarUnitMonth |
NSCalendarUnitYear fromDate:myDate];
NSCalendar *calendar = [NSCalendar currentCalendar];
NSRange weekdayRange = [calendar maximumRangeOfUnit:NSWeekdayCalendarUnit];
NSDateComponents *_components = [calendar components:NSWeekdayCalendarUnit fromDate:myDate];
NSUInteger weekdayOfDate = [_components weekday];
if (weekdayOfDate == weekdayRange.location || weekdayOfDate == weekdayRange.length) {
axisTextStyle.color = [CPTColor orangeColor];
CPTPlotRange *bandRange;
bandRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromDouble((double)z-1) length:CPTDecimalFromDouble(1)];
CPTColor *areaColor = [CPTColor colorWithComponentRed:1.0 green:1.0 blue:1.0 alpha:0.1];
CPTColor *areaColorEnd = [CPTColor colorWithComponentRed:1.0 green:1.0 blue:1.0 alpha:1.0];
CPTGradient *areaGradient = [CPTGradient gradientWithBeginningColor:areaColor endingColor:areaColorEnd];
areaGradient.angle = -90.0f;
CPTFill *areaGradientFill = [CPTFill fillWithGradient:areaGradient];
areaGradient.angle = -90.0f;
areaGradientFill = [CPTFill fillWithGradient:areaGradient];
[x addBackgroundLimitBand:[CPTLimitBand limitBandWithRange:bandRange fill:areaGradientFill]];
} else {
axisTextStyle.color = [CPTColor whiteColor];
}
axisTextStyle.textAlignment = CPTAlignmentCenter;
x.labelTextStyle = axisTextStyle;
CPTAxisLabel *label = [[CPTAxisLabel alloc]
initWithText:[NSString stringWithFormat:@"%i\n%@",[components day], _weekDays[weekdayOfDate]]
textStyle:x.labelTextStyle];
label.alignment = CPTAlignmentRight;
NSDecimal location = CPTDecimalFromInteger(contador);
label.tickLocation = CPTDecimalFromCGFloat(contador);
//label.offset = x.majorTickLength - 10;
if (label){
[xLabels addObject:label];
}
[xLocations addObject:[NSDecimalNumber decimalNumberWithDecimal:location]];
z++;
}
axisTextStyle.color = [CPTColor whiteColor];
axisTextStyle.textAlignment = CPTAlignmentCenter;
x.axisLabels = xLabels;
x.majorTickLocations = xLocations;
CPTXYAxis *y = axisSet.yAxis;
// y.title = @"";
y.titleTextStyle = axisTitleStyle;
// y.titleOffset = -40.0f;
y.axisLineStyle = axisLineStyle;
y.majorTickLineStyle = axisLineStyle;
// y.minorTickLineStyle = nil;
y.majorGridLineStyle = majorGridLineStyle;
// y.minorGridLineStyle = minorGridLineStyle;
y.labelingPolicy = CPTAxisLabelingPolicyNone;
y.labelTextStyle = axisTextStyle;
y.labelOffset = 36.0f;
//y.majorTickLineStyle = axisLineStyle;
//y.majorTickLength = 4.0f;
//y.minorTickLength = 1.0f;
y.gridLinesRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(-1.0f) length:CPTDecimalFromFloat(45.0f)];
y.tickDirection = CPTSignPositive;
NSInteger majorIncrement = 10000000;
NSInteger minorIncrement = 10000000;
CGFloat yMax = 180000000; // should determine dynamically based on max price
NSMutableSet *yLabels = [NSMutableSet set];
// NSMutableSet *yMajorLocations = [NSMutableSet set];
// NSMutableSet *yMinorLocations = [NSMutableSet set];
NSMutableSet *yLocations = [NSMutableSet set];
for (NSInteger j = minorIncrement; j <= yMax; j += minorIncrement) {
NSUInteger mod = j % majorIncrement;
NSNumberFormatter *numFormatter = [[NSNumberFormatter alloc] init];
[numFormatter setNumberStyle:NSNumberFormatterDecimalStyle];
if (mod == 0) {
CPTAxisLabel *label = [[CPTAxisLabel alloc] initWithText:[numFormatter stringFromNumber:[NSNumber numberWithInt:j]] textStyle:y.labelTextStyle];
NSDecimal location = CPTDecimalFromInteger(j);
label.tickLocation = location;
label.offset = -y.majorTickLength - y.labelOffset - 60;
if (label) {
[yLabels addObject:label];
}
[yLocations addObject:[NSDecimalNumber decimalNumberWithDecimal:location]];
}
}
y.axisLabels = yLabels;
// y.majorTickLocations = yMajorLocations;
// y.minorTickLocations = yMinorLocations;
y.majorTickLocations = yLocations;
}
答案 0 :(得分：1)
您应该使用约束来定位y轴，使其在图表滚动时不会移动。
y.axisConstraints = [CPTConstraints constraintWithLowerOffset:0.0];
kMaxDataPoints的价值是多少？如果它大于数据点的数量，则图形将不会滚动。