core-Plot学习二 自定义CorePlot label及majorGridLine莫名其妙消失的Bug

设置corePlot可拖动： 

plotSpace.allowsUserInteraction = YES;  

设置x显示的范围：

plotSpace.xRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromInt(8 * oneDay)length:CPTDecimalFromInt(23 * oneDay)];  

设置x轴拖动范围：

plotSpace.globalXRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromInt(0) length:CPTDecimalFromInt(31 * oneDay)];  

禁止corePlot缩放(Self是CPTGraphHostingView)：

    [self setAllowPinchScaling:NO];//禁止缩放  

自定义label：

    x.axisLabels = [self buildLabelTitle];  

    x.labelingPolicy = CPTAxisLabelingPolicyNone;  

      

    //构建30天的label样式  

    - (NSMutableSet*)buildLabelTitle  

    {  

        NSMutableSet *newAxisLabels = [NSMutableSet set];  

          

        CPTMutableTextStyle *textStyleB = [CPTMutableTextStyle textStyle];  

        textStyleB.color = [CPTColor colorWithComponentRed:CPTFloat((float)0x09/0xFF) green:CPTFloat((float)0x31/0xFF) blue:CPTFloat((float)0x4A/0xFF) alpha:CPTFloat(1.0)];  

        NSDateFormatter *dateFormatter = [[[NSDateFormatter alloc] init] autorelease];  

        [dateFormatter setDateFormat:@"MM.dd"];  

      

        int n = 1;  

        for ( NSUInteger i = 29; i > 0; i--) //从今起前29天  

        {  

            NSTimeInterval secondsPerDay = 24 * 60 * 60 * i;  

            NSDate *ago = [[NSDate alloc] initWithTimeIntervalSinceNow:-secondsPerDay];  

            CPTAxisLabel *newLabel = [[CPTAxisLabel alloc] initWithText:[dateFormatter stringFromDate:ago]  

                                                              textStyle:textStyleB];  

            [ago release];  

            newLabel.tickLocation = CPTDecimalFromUnsignedInteger(n++ * oneDay);  

            newLabel.offset = 5;  

            [self.locationLabels addObject:[NSNumber numberWithInt:(n-1) * oneDay]];  

            [newAxisLabels addObject:newLabel];  

            [newLabel release];  

        }  

          

        //今天  

        CPTMutableTextStyle *textStyleW = [CPTMutableTextStyle textStyle];  

        textStyleW.color = [CPTColor whiteColor];  

        CPTAxisLabel *newLabel = [[CPTAxisLabel alloc] initWithText:@"今日" textStyle:textStyleW];  

        newLabel.tickLocation = CPTDecimalFromUnsignedInteger(oneDay * n);  

        [self.locationLabels addObject:[NSNumber numberWithInt:(n) * oneDay]];  

        newLabel.offset = 5;  

        [newAxisLabels addObject:newLabel];  

        [newLabel release];  

          

        return newAxisLabels;  

    }  

View Code

但是写好后发现majorGridLine不见了，之后各种折腾后终于找到原因是：

CPTAxisLabelingPolicyNone       No labels provided; user sets labels and tick locations.

设置这个属性是要自己重新定义majorGridLine位置的

所以需要使用：

 

    x.majorTickLocations = [NSSet setWithArray:locationLabels];