我在使用 单击绘图符号时显示了注释plotSymbolWasSelectedAtRecordIndex，但是对于某些绘图符号，它们看起来很远，而对于符号附近的一些符号，就像它应该的那样。例如，当单击图表中的最小点时， 会CTPPlotSpaceAnnotiation出现在屏幕左侧，而不是该点附近。
编辑：我想出了问题所在。NSNumber x 没有值，因为变量 dates 是一个 NSString，我认为它必须先转换为 NSDate，然后再转换为 NSNumber。我应该从变量日期中获取月数吗？，以便在变量锚点中使用它，以便注释将显示在绘图符号附近。
另一个编辑：就像我上面说的，我将 NSString 日期转换为 NSDate，然后转换为 NSNumber，当我现在调试时，它显示了我认为的天数。但是现在当我单击绘图符号时，注释不再出现。例如，如果日期是 07.2010，则 x 获取值 299624400.0，并且注释不再起作用。
这是代码：
-(void)scatterPlot:(CPTScatterPlot *)plot plotSymbolWasSelectedAtRecordIndex:(NSUInteger)index
{
if ( symbolTextAnnotation ) {
[graph.plotAreaFrame.plotArea removeAnnotation:symbolTextAnnotation];
symbolTextAnnotation = nil;
}
// Setup a style for the annotation
CPTMutableTextStyle *hitAnnotationTextStyle = [CPTMutableTextStyle textStyle];
hitAnnotationTextStyle.color = [CPTColor whiteColor];
hitAnnotationTextStyle.fontSize = 16.0f;
hitAnnotationTextStyle.fontName = @"Helvetica-Bold";
// Determine point of symbol in plot coordinates
NSNumber *x = [[CPDStockPriceStore sharedInstance].dates objectAtIndex:index];
NSNumber *y = [[CPDStockPriceStore sharedInstance].prices objectAtIndex:index];
NSArray *anchorPoint = [NSArray arrayWithObjects:x, y, nil];
NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init];
[formatter setMaximumFractionDigits:2];
NSString *currentValue = [formatter stringFromNumber:[[CPDStockPriceStore sharedInstance].prices objectAtIndex:index]];
currentValue = [currentValue stringByAppendingString:@"-"];
NSString *currentValue1 = [[CPDStockPriceStore sharedInstance].dates objectAtIndex:index];
// Now add the annotation to the plot area
CPTTextLayer *textLayer = [[CPTTextLayer alloc] initWithText:[currentValue stringByAppendingString:currentValue1] style:hitAnnotationTextStyle];
symbolTextAnnotation = [[CPTPlotSpaceAnnotation alloc] initWithPlotSpace:graph.defaultPlotSpace anchorPlotPoint:anchorPoint];
symbolTextAnnotation.contentLayer = textLayer;
symbolTextAnnotation.displacement = CGPointMake(0.0f, 10.0f);
[graph.plotAreaFrame.plotArea addAnnotation:symbolTextAnnotation];
}
这是绘图、x 轴和 y 轴的代码：-(void)configurePlots {
// 1 - Get graph and plot space
graph = self.hostView.hostedGraph;
plotSpace = (CPTXYPlotSpace *) graph.defaultPlotSpace;
// 2 - Create the three plots
aaplPlot = [[CPTScatterPlot alloc] init];
aaplPlot.dataSource = self;
aaplPlot.delegate = self;
aaplPlot.plotSymbolMarginForHitDetection = 20.0f;
aaplPlot.identifier = CPDTickerSymbolAAPL;
CPTColor *aaplColor = [CPTColor redColor];
[graph addPlot:aaplPlot toPlotSpace:plotSpace];
msftPlot = [[CPTScatterPlot alloc] init];
msftPlot.dataSource = self;
msftPlot.identifier = CPDTickerSymbolMSFT;
CPTColor *msftColor = [CPTColor clearColor];
[graph addPlot:msftPlot toPlotSpace:plotSpace];
// 3 - Set up plot space
NSArray *array = [[NSArray alloc] initWithObjects:aaplPlot, msftPlot, nil];
[plotSpace scaleToFitPlots:array];
CPTMutablePlotRange *xRange = [plotSpace.xRange mutableCopy];
[xRange expandRangeByFactor:CPTDecimalFromCGFloat(1.1f)];
plotSpace.xRange = xRange;
CPTMutablePlotRange *yRange = [plotSpace.yRange mutableCopy];
[yRange expandRangeByFactor:CPTDecimalFromCGFloat(1.2f)];
plotSpace.yRange = yRange;
// 4 - Create styles and symbols
CPTMutableLineStyle *aaplLineStyle = [aaplPlot.dataLineStyle mutableCopy];
aaplLineStyle.lineWidth = 2.5;
aaplLineStyle.lineColor = aaplColor;
aaplPlot.dataLineStyle = aaplLineStyle;
CPTMutableLineStyle *aaplSymbolLineStyle = [CPTMutableLineStyle lineStyle];
aaplSymbolLineStyle.lineColor = aaplColor;
CPTPlotSymbol *aaplSymbol = [CPTPlotSymbol ellipsePlotSymbol];
aaplSymbol.fill = [CPTFill fillWithColor:aaplColor];
aaplSymbol.lineStyle = aaplSymbolLineStyle;
aaplSymbol.size = CGSizeMake(6.0f, 6.0f);
aaplPlot.plotSymbol = aaplSymbol;
}
-(void)configureAxes {
// 1 - Create styles
CPTMutableTextStyle *axisTitleStyle = [CPTMutableTextStyle textStyle];
axisTitleStyle.color = [CPTColor whiteColor];
axisTitleStyle.fontName = @"Helvetica-Bold";
axisTitleStyle.fontSize = 12.0f;
CPTMutableLineStyle *axisLineStyle = [CPTMutableLineStyle lineStyle];
axisLineStyle.lineWidth = 2.0f;
axisLineStyle.lineColor = [CPTColor whiteColor];
CPTMutableTextStyle *axisTextStyle = [[CPTMutableTextStyle alloc] init];
axisTextStyle.color = [CPTColor whiteColor];
axisTextStyle.fontName = @"Helvetica-Bold";
axisTextStyle.fontSize = 11.0f;
CPTMutableLineStyle *tickLineStyle = [CPTMutableLineStyle lineStyle];
tickLineStyle.lineColor = [CPTColor whiteColor];
tickLineStyle.lineWidth = 2.0f;
CPTMutableLineStyle *gridLineStyle = [CPTMutableLineStyle lineStyle];
tickLineStyle.lineColor = [CPTColor blackColor];
tickLineStyle.lineWidth = 1.0f;
// 2 - Get axis set
CPTXYAxisSet *axisSet = (CPTXYAxisSet *) self.hostView.hostedGraph.axisSet;
// 3 - Configure x-axis
CPTAxis *x = axisSet.xAxis;
x.title = @"Ziua Lunii";
x.titleTextStyle = axisTitleStyle;
x.titleOffset = 15.0f;
x.axisLineStyle = axisLineStyle;
x.labelingPolicy = CPTAxisLabelingPolicyNone;
x.labelTextStyle = axisTextStyle;
x.majorTickLineStyle = axisLineStyle;
x.majorTickLength = 4.0f;
x.tickDirection = CPTSignNegative;
CGFloat dateCount = [[[CPDStockPriceStore sharedInstance] datesInMonth] count];
NSMutableSet *xLabels = [NSMutableSet setWithCapacity:dateCount];
NSMutableSet *xLocations = [NSMutableSet setWithCapacity:dateCount];
NSInteger i = 0;
for (NSString *date in [[CPDStockPriceStore sharedInstance] datesInMonth]) {
CPTAxisLabel *label = [[CPTAxisLabel alloc] initWithText:date textStyle:x.labelTextStyle];
label.rotation = M_PI/4;
CGFloat location = i++;
label.tickLocation = CPTDecimalFromCGFloat(location);
label.offset = x.majorTickLength;
if (label) {
[xLabels addObject:label];
[xLocations addObject:[NSNumber numberWithFloat:location]];
}
}
x.axisLabels = xLabels;
x.majorTickLocations = xLocations;
// 4 - Configure y-axis
CPTAxis *y = axisSet.yAxis;
y.title = @"Pret";
y.titleTextStyle = axisTitleStyle;
y.titleOffset = -50.0f;
y.axisLineStyle = axisLineStyle;
y.majorGridLineStyle = gridLineStyle;
y.labelingPolicy = CPTAxisLabelingPolicyNone;
y.labelTextStyle = axisTextStyle;
y.labelOffset = 23.0f;
y.majorTickLineStyle = axisLineStyle;
y.majorTickLength = 4.0f;
y.minorTickLength = 2.0f;
y.tickDirection = CPTSignPositive;
NSInteger majorIncrement = 100;
NSInteger minorIncrement = 50;
CGFloat yMax = 1300.0f; // should determine dynamically based on max price
NSMutableSet *yLabels = [NSMutableSet set];
NSMutableSet *yMajorLocations = [NSMutableSet set];
NSMutableSet *yMinorLocations = [NSMutableSet set];
for (NSInteger j = minorIncrement; j <= yMax; j += minorIncrement) {
NSUInteger mod = j % majorIncrement;
if (mod == 0) {
CPTAxisLabel *label = [[CPTAxisLabel alloc] initWithText:[NSString stringWithFormat:@"%i", j] textStyle:y.labelTextStyle];
NSDecimal location = CPTDecimalFromInteger(j);
label.tickLocation = location;
label.offset = - y.majorTickLength - y.labelOffset;
if (label) {
[yLabels addObject:label];
}
[yMajorLocations addObject:[NSDecimalNumber decimalNumberWithDecimal:location]];
} else {
[yMinorLocations addObject:[NSDecimalNumber decimalNumberWithDecimal:CPTDecimalFromInteger(j)]];
}
}
y.axisLabels = yLabels;
y.majorTickLocations = yMajorLocations;
y.minorTickLocations = yMinorLocations;
}