为什么我的图形在iOS 8的视图中如此缓慢？

Question

我正在开发一个图表。在我的图形视图控制器中，我使用了带有三个按钮"Growth“、"Dancis”、"Ponderal“的UISegmentView。当用户点击段按钮时，我想显示三个不同的图形。

当我点击"Dancis“按钮来显示一个图形时，会花费大量的时间，我不明白为什么要花这么长时间。

我的代码如下：

- (void)viewDidLoad {
    [super viewDidLoad];
    mainSegment = [[UISegmentedControl alloc] initWithItems:[NSArray arrayWithObjects:@"Growth", @"Dancis", @"Ponderal Index",nil]];

    mainSegment.frame = CGRectMake(250,80,320,43);
    [self.view addSubview:mainSegment];
    // mainSegment.selectedSegmentIndex = 0;
    [mainSegment setWidth:130 forSegmentAtIndex:2];
    [mainSegment setWidth:95 forSegmentAtIndex:1];
    [mainSegment setWidth:95 forSegmentAtIndex:0];
    [mainSegment addTarget:self action:@selector(mainSegmentControl:) forControlEvents: UIControlEventValueChanged];
    [self.view addSubview:mainSegment];

    growthView = [[UIView alloc]initWithFrame:CGRectMake(0 ,125, self.view.frame.size.width, self.view.frame.size.height)];
    [self.view addSubview:growthView];

    dancisView = [[UIView alloc]initWithFrame:CGRectMake(0 ,125, self.view.frame.size.width, self.view.frame.size.height)];
    [self.view addSubview:dancisView];

    ponderalIndexView = [[UIView alloc]initWithFrame:CGRectMake(0 ,125, self.view.frame.size.width, self.view.frame.size.height)];
    [self.view addSubview:ponderalIndexView];

    // Do any additional setup after loading the view.
}


- (void)mainSegmentControl:(UISegmentedControl *)segment
{
    if(mainSegment.selectedSegmentIndex == 0)
    {
        [dancisView setHidden:YES];
        [ponderalIndexView setHidden:YES];
        [growthView setHidden:NO];
        [self initPlot];
    }
    else if(mainSegment.selectedSegmentIndex == 1)
    {
        [dancisView setHidden:NO];
        [ponderalIndexView setHidden:YES];
        [growthView setHidden:YES];

        [self initPlotForDancis];
    }
    else
    {
        [dancisView setHidden:YES];
        [ponderalIndexView setHidden:NO];
        [growthView setHidden:YES];
        [self initPlotForPonderalIndex];
    }
}

生长图包含两个y轴

-(void)configureHost {
    self.hostView = [(CPTGraphHostingView *) [CPTGraphHostingView alloc] initWithFrame:CGRectMake(0 ,0, growthView.frame.size.width, growthView.frame.size.height-150)];
    self.hostView.allowPinchScaling = YES;
    [growthView addSubview:self.hostView];
}


-(void)configureGraph {
    // 1 - Create the graph
    CPTGraph *graph = [[CPTXYGraph alloc] initWithFrame:self.hostView.bounds];
    [graph applyTheme:[CPTTheme themeNamed:kCPTDarkGradientTheme]];
    self.hostView.hostedGraph = graph;

    // 2 - Set graph title
    NSString *title = @"Ponderal Index Graph";
    graph.title = title;
    // 3 - Create and set text style
    CPTMutableTextStyle *titleStyle = [CPTMutableTextStyle textStyle];
    titleStyle.color = [CPTColor whiteColor];
    titleStyle.fontName = @"Helvetica-Bold";
    titleStyle.fontSize = 16.0f;
    graph.titleTextStyle = titleStyle;
    graph.titlePlotAreaFrameAnchor = CPTRectAnchorTop;
    graph.titleDisplacement = CGPointMake(0.0f, 10.0f);
    // 4 - Set padding for plot area
    [graph.plotAreaFrame setPaddingLeft:80.0f];
    [graph.plotAreaFrame setPaddingBottom:80.0f];
    [graph.plotAreaFrame setPaddingRight:80.0f];
    // [graph.plotAreaFrame setPaddingBottom:50.0f];

    // 5 - Enable user interactions for plot space
    CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *) graph.defaultPlotSpace;
    plotSpace.allowsUserInteraction = YES;
    plotSpace.delegate = self;

    self.hostView.allowPinchScaling = YES;

}

-(void)configurePlots {

    // 1 - Get graph and plot space
    CPTGraph *graph = self.hostView.hostedGraph;
    CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *) graph.defaultPlotSpace;
    // 2 - Create the three plots
    CPTScatterPlot *aaplPlot = [[CPTScatterPlot alloc] init];
    aaplPlot.dataSource = self;
    [plotSpace setDelegate:self];
    aaplPlot.identifier = CPDTickerSymbolAAPL;
    CPTColor *aaplColor = [CPTColor redColor];
    [graph addPlot:aaplPlot toPlotSpace:plotSpace];
    CPTScatterPlot *googPlot = [[CPTScatterPlot alloc] init];
    googPlot.dataSource = self;
    googPlot.identifier = CPDTickerSymbolGOOG;
    CPTColor *googColor = [CPTColor greenColor];
    [graph addPlot:googPlot toPlotSpace:plotSpace];
    CPTScatterPlot *msftPlot = [[CPTScatterPlot alloc] init];
    msftPlot.dataSource = self;
    msftPlot.identifier = CPDTickerSymbolMSFT;
    CPTColor *msftColor = [CPTColor blueColor];
    [graph addPlot:msftPlot toPlotSpace:plotSpace];
    // 3 - Set up plot space
    [plotSpace scaleToFitPlots:[NSArray arrayWithObjects:aaplPlot, googPlot, msftPlot, nil]];
    CPTMutablePlotRange *xRange = [plotSpace.xRange mutableCopy];
    [xRange expandRangeByFactor:CPTDecimalFromCGFloat(3.0f)];
    plotSpace.xRange = xRange;
    CPTMutablePlotRange *yRange = [plotSpace.yRange mutableCopy];
    [yRange expandRangeByFactor:CPTDecimalFromCGFloat(1.2f)];
    plotSpace.yRange = yRange;

    plotSpace.delegate = self;

    // 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;
    CPTMutableLineStyle *googLineStyle = [googPlot.dataLineStyle mutableCopy];
    googLineStyle.lineWidth = 1.0;
    googLineStyle.lineColor = googColor;
    googPlot.dataLineStyle = googLineStyle;
    CPTMutableLineStyle *googSymbolLineStyle = [CPTMutableLineStyle lineStyle];
    googSymbolLineStyle.lineColor = googColor;
    CPTPlotSymbol *googSymbol = [CPTPlotSymbol starPlotSymbol];
    googSymbol.fill = [CPTFill fillWithColor:googColor];
    googSymbol.lineStyle = googSymbolLineStyle;
    googSymbol.size = CGSizeMake(6.0f, 6.0f);
    googPlot.plotSymbol = googSymbol;
    CPTMutableLineStyle *msftLineStyle = [msftPlot.dataLineStyle mutableCopy];
    msftLineStyle.lineWidth = 2.0;
    msftLineStyle.lineColor = msftColor;
    msftPlot.dataLineStyle = msftLineStyle;
    CPTMutableLineStyle *msftSymbolLineStyle = [CPTMutableLineStyle lineStyle];
    msftSymbolLineStyle.lineColor = msftColor;
    CPTPlotSymbol *msftSymbol = [CPTPlotSymbol diamondPlotSymbol];
    msftSymbol.fill = [CPTFill fillWithColor:msftColor];
    msftSymbol.lineStyle = msftSymbolLineStyle;
    msftSymbol.size = CGSizeMake(6.0f, 6.0f);
    msftPlot.plotSymbol = msftSymbol;

}

-(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
    CPTXYAxis *x = axisSet.xAxis;
    x.title = @"GA in Week";
    x.titleTextStyle = axisTitleStyle;
    x.titleOffset = 25.0f;
    x.axisLineStyle = axisLineStyle;
    x.labelingPolicy = CPTAxisLabelingPolicyNone;
    x.labelTextStyle = axisTextStyle;
    x.majorTickLineStyle = axisLineStyle;
    x.majorTickLength = 4.0f;
    x.tickDirection = CPTSignNegative;
    x.axisConstraints = [CPTConstraints constraintWithLowerOffset:15.0];

    NSInteger majorIncrementx = 5;
    NSInteger minorIncrementx =1;
    CGFloat xMax = 50000.0f;  // should determine dynamically based on max price
    NSMutableSet *xLabels = [NSMutableSet set];
    NSMutableSet *xMajorLocations = [NSMutableSet set];
    NSMutableSet *xMinorLocations = [NSMutableSet set];

    // NSInteger m = 0;
    for (NSInteger j = minorIncrementx; j <= xMax; j += minorIncrementx) {
        NSUInteger mod = j % majorIncrementx;
        if (mod == 0) {
            CPTAxisLabel *label = [[CPTAxisLabel alloc] initWithText:[NSString stringWithFormat:@"%i", j] textStyle:x.labelTextStyle];
            NSDecimal location = CPTDecimalFromInteger(j-10);
            // CGFloat location = m+5;
            label.tickLocation = location;
            label.offset = -x.majorTickLength+10 - x.labelOffset+10;
            if (label) {
                [xLabels addObject:label];
            }
            [xMajorLocations addObject:[NSDecimalNumber decimalNumberWithDecimal:location]];
        } else {
            [xMinorLocations addObject:[NSDecimalNumber decimalNumberWithDecimal:CPTDecimalFromInteger(j)]];
        }
    }
    x.axisLabels = xLabels;
    x.majorTickLocations = xMajorLocations;
    x.minorTickLocations = xMinorLocations;


    // 4 - Configure y-axis
    CPTXYAxis *y = axisSet.yAxis;
    y.title = @"PI %";
    y.titleTextStyle = axisTitleStyle;
    y.titleOffset = 30.0f;
    y.axisLineStyle = axisLineStyle;
    y.majorGridLineStyle = gridLineStyle;
    y.labelingPolicy = CPTAxisLabelingPolicyNone;
    y.labelTextStyle = axisTextStyle;
    y.labelOffset = -10.0f;
    y.majorTickLineStyle = axisLineStyle;
    y.majorTickLength = 4.0f;
    y.minorTickLength = 2.0f;
    y.tickDirection = CPTSignNegative;
    y.axisConstraints = [CPTConstraints constraintWithLowerOffset:10.0];

    NSInteger majorIncrement = 1;
    NSInteger minorIncrement =1;
    CGFloat yMax = 50000.0f;  // 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);
            NSDecimal location = CPTDecimalFromInteger(j*30);

            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;

    CPTGraph *graph = self.hostView.hostedGraph;
    //CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *) graph.defaultPlotSpace;


    CPTXYPlotSpace *plotSpace2 =(CPTXYPlotSpace *) graph.defaultPlotSpace;
    //[[CPTXYPlotSpace alloc] init];
    plotSpace2.delegate = self;
    plotSpace2.allowsUserInteraction = YES;


    [graph addPlotSpace:plotSpace2];

    CPTXYAxis *y2 = [[CPTXYAxis alloc] init] ;
    // 4 - Configure y-axis
    y2.title = @"lenght ";
    y2.titleTextStyle = axisTitleStyle;
    y2.titleOffset = 10.0f;
    y2.axisLineStyle = axisLineStyle;
    y2.majorGridLineStyle = gridLineStyle;
    y2.labelingPolicy = CPTAxisLabelingPolicyNone;
    y2.labelTextStyle = axisTextStyle;
    y2.labelOffset = 50.0f;
    y2.majorTickLineStyle = axisLineStyle;
    y2.majorTickLength = 4.0f;
    y2.minorTickLength = 2.0f;
    y2.tickDirection = CPTSignNegative;
    y2.coordinate = CPTCoordinateY;
    y2.axisConstraints = [CPTConstraints constraintWithUpperOffset:20.0];
    y2.coordinate = CPTCoordinateY;
    y2.plotSpace = plotSpace2;

    NSInteger majorIncrement2 = 100;
    NSInteger minorIncrement2 = 50;
    CGFloat y2Max = 50000.0f;  // should determine dynamically based on max price
    NSMutableSet *y2Labels = [NSMutableSet set];

    NSMutableSet *y2MajorLocations = [NSMutableSet set];
    NSMutableSet *y2MinorLocations = [NSMutableSet set];

    for (NSInteger j = minorIncrement2; j <= y2Max; j += minorIncrement2) {
        NSUInteger mod = j % majorIncrement2;
        if (mod == 0) {
            CPTAxisLabel *label = [[CPTAxisLabel alloc] initWithText:[NSString stringWithFormat:@"%i", j] textStyle:y.labelTextStyle];
            NSDecimal location = CPTDecimalFromInteger(j);
            // NSDecimal location = CPTDecimalFromInteger(j*30);

            label.tickLocation = location;
            label.offset = -y2.majorTickLength - y2.labelOffset;
            if (label) {
                [y2Labels addObject:label];
            }
            [y2MajorLocations addObject:[NSDecimalNumber decimalNumberWithDecimal:location]];
        } else {
            [y2MinorLocations addObject:[NSDecimalNumber decimalNumberWithDecimal:CPTDecimalFromInteger(j)]];
        }
    }

    axisSet.axes = [NSArray arrayWithObjects:x, y,y2, nil];

    y2.axisLabels = y2Labels;
    y2.majorTickLocations = y2MajorLocations;
    y2.minorTickLocations = y2MinorLocations;
}

-(NSNumber*) numberForPlot:(CPTPlot *)plot field:(NSUInteger)fieldEnum recordIndex:      (NSUInteger)idx {

    babyWeight = [[NSMutableArray alloc]init];

    [babyWeight insertObject:@"150" atIndex:0];
    [babyWeight insertObject:@"200" atIndex:1];
    [babyWeight insertObject:@"800" atIndex:2];
    [babyWeight insertObject:@"1000" atIndex:3];
    [babyWeight insertObject:@"1500" atIndex:4];


    switch ( fieldEnum ) {
        case CPTBarPlotFieldBarLocation:
            return @(idx);
            break;

        case CPTBarPlotFieldBarTip:
            return [babyWeight objectAtIndex:idx];
            break;

        default:
            break;
    }

    return nil;
}

- (CPTPlotRange *)plotSpace:(CPTPlotSpace *)space
      willChangePlotRangeTo:(CPTPlotRange *)newRange
              forCoordinate:(CPTCoordinate)coordinate
{
    if (coordinate == CPTCoordinateY) {
        newRange = ((CPTXYPlotSpace*)space).yRange;

       // return newRange;
    }
     return newRange;
}

@end

Answer 1

您正在创建100,000多个轴标签。这需要时间，而且会给应用程序带来很大的内存压力。选择主要的和次要的增量，以便应用程序只为每个轴生成合理数量的标签。