在coreplot中啓用x軸（水平）滾動

Question

我使用的代碼來自this link。而目前如果我有50欄欄或150欄欄，那麼下面的標籤是壓縮的，我想水平滾動X軸而不是壓縮的X軸。

我已經試過這樣：

plotSpace.xRange = CPTPlotRangeplotRangeWithLocation:CPTDecimalFromInt(-1)length:CPTDecimalFromInt(50)]; 

從文件附加代碼：

#import "GraphView.h" 

@implementation GraphView 

- (void)generateData 
{ 
    NSMutableDictionary *dataTemp = [[NSMutableDictionary alloc] init]; 

    //Array containing all the dates that will be displayed on the X axis 
    dates = [NSArray arrayWithObjects:@"2012-05-01", @"2012-05-02", @"2012-05-03", 
      @"2012-05-04", @"2012-05-05", @"2012-05-06", @"2012-05-07", nil]; 

    //Dictionary containing the name of the two sets and their associated color 
    //used for the demo 
    sets = [NSDictionary dictionaryWithObjectsAndKeys:[UIColor blueColor], @"Plot 1", 
      [UIColor redColor], @"Plot 2", 
      [UIColor greenColor], @"Plot 3", nil]; 

    //Generate random data for each set of data that will be displayed for each day 
    //Numbers between 1 and 10 
    for (NSString *date in dates) { 
     NSMutableDictionary *dict = [NSMutableDictionary dictionary]; 
     for (NSString *set in sets) { 
      NSNumber *num = [NSNumber numberWithInt:arc4random_uniform(10)+1]; 
      [dict setObject:num forKey:set]; 
     } 
     [dataTemp setObject:dict forKey:date]; 
    } 

    data = [dataTemp copy]; 
    [dataTemp release]; 

    NSLog(@"%@", data); 
} 

- (void)generateLayout 
{ 
    //Create graph from theme 
    graph        = [[CPTXYGraph alloc] initWithFrame:CGRectZero]; 
    [graph applyTheme:[CPTTheme themeNamed:kCPTStocksTheme]]; 
    self.hostedGraph     = graph; 
    graph.plotAreaFrame.masksToBorder = NO; 
    graph.paddingLeft     = 0.0f; 
    graph.paddingTop     = 0.0f; 
    graph.paddingRight     = 0.0f; 
    graph.paddingBottom     = 0.0f; 

    CPTMutableLineStyle *borderLineStyle = [CPTMutableLineStyle lineStyle]; 
    borderLineStyle.lineColor    = [CPTColor whiteColor]; 
    borderLineStyle.lineWidth    = 2.0f; 
    graph.plotAreaFrame.borderLineStyle  = borderLineStyle; 
    graph.plotAreaFrame.paddingTop   = 10.0; 
    graph.plotAreaFrame.paddingRight  = 10.0; 
    graph.plotAreaFrame.paddingBottom  = 80.0; 
    graph.plotAreaFrame.paddingLeft   = 70.0; 

    //Add plot space 
    CPTXYPlotSpace *plotSpace  = (CPTXYPlotSpace *)graph.defaultPlotSpace; 
    plotSpace.delegate    = self; 
    plotSpace.yRange    = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromInt(0) 
                    length:CPTDecimalFromInt(10 * sets.count)]; 
    plotSpace.xRange    = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromInt(-1) 
                    length:CPTDecimalFromInt(8)]; 

    //Grid line styles 
    CPTMutableLineStyle *majorGridLineStyle = [CPTMutableLineStyle lineStyle]; 
    majorGridLineStyle.lineWidth   = 0.75; 
    majorGridLineStyle.lineColor   = [[CPTColor whiteColor] colorWithAlphaComponent:0.1]; 
    CPTMutableLineStyle *minorGridLineStyle = [CPTMutableLineStyle lineStyle]; 
    minorGridLineStyle.lineWidth   = 0.25; 
    minorGridLineStyle.lineColor   = [[CPTColor whiteColor] colorWithAlphaComponent:0.1]; 

    //Axes 
    CPTXYAxisSet *axisSet = (CPTXYAxisSet *)graph.axisSet; 

    //X axis 
    CPTXYAxis *x     = axisSet.xAxis; 
    x.orthogonalCoordinateDecimal = CPTDecimalFromInt(0); 
    x.majorIntervalLength   = CPTDecimalFromInt(1); 
    x.minorTicksPerInterval   = 0; 
    x.labelingPolicy    = CPTAxisLabelingPolicyNone; 
    x.majorGridLineStyle   = majorGridLineStyle; 
    x.axisConstraints    = [CPTConstraints constraintWithLowerOffset:0.0]; 

    //X labels 
    int labelLocations = 0; 
    NSMutableArray *customXLabels = [NSMutableArray array]; 
    for (NSString *day in dates) { 
     CPTAxisLabel *newLabel = [[CPTAxisLabel alloc] initWithText:day textStyle:x.labelTextStyle]; 
     newLabel.tickLocation = [[NSNumber numberWithInt:labelLocations] decimalValue]; 
     newLabel.offset   = x.labelOffset + x.majorTickLength; 
     newLabel.rotation  = M_PI/4; 
     [customXLabels addObject:newLabel]; 
     labelLocations++; 
     [newLabel release]; 
    } 
    x.axisLabels     = [NSSet setWithArray:customXLabels]; 

    //Y axis 
    CPTXYAxis *y   = axisSet.yAxis; 
    y.title     = @"Value"; 
    y.titleOffset   = 50.0f; 
    y.labelingPolicy  = CPTAxisLabelingPolicyAutomatic; 
    y.majorGridLineStyle = majorGridLineStyle; 
    y.minorGridLineStyle = minorGridLineStyle; 
    y.axisConstraints  = [CPTConstraints constraintWithLowerOffset:0.0]; 

    //Create a bar line style 
    CPTMutableLineStyle *barLineStyle = [[[CPTMutableLineStyle alloc] init] autorelease]; 
    barLineStyle.lineWidth    = 1.0; 
    barLineStyle.lineColor    = [CPTColor whiteColor]; 
    CPTMutableTextStyle *whiteTextStyle = [CPTMutableTextStyle textStyle]; 
    whiteTextStyle.color    = [CPTColor whiteColor]; 

    //Plot 
    BOOL firstPlot = YES; 
    for (NSString *set in [[sets allKeys] sortedArrayUsingSelector:@selector(localizedCaseInsensitiveCompare:)]) { 
     CPTBarPlot *plot  = [CPTBarPlot tubularBarPlotWithColor:[CPTColor blueColor] horizontalBars:NO]; 
     plot.lineStyle   = barLineStyle; 
     CGColorRef color  = ((UIColor *)[sets objectForKey:set]).CGColor; 
     plot.fill    = [CPTFill fillWithColor:[CPTColor colorWithCGColor:color]]; 
     if (firstPlot) { 
      plot.barBasesVary = NO; 
      firstPlot   = NO; 
     } else { 
      plot.barBasesVary = YES; 
     } 
     plot.barWidth   = CPTDecimalFromFloat(0.8f); 
     plot.barsAreHorizontal = NO; 
     plot.dataSource   = self; 
     plot.identifier   = set; 
     [graph addPlot:plot toPlotSpace:plotSpace]; 
    } 

    //Add legend 
    CPTLegend *theLegend  = [CPTLegend legendWithGraph:graph]; 
    theLegend.numberOfRows = sets.count; 
    theLegend.fill   = [CPTFill fillWithColor:[CPTColor colorWithGenericGray:0.15]]; 
    theLegend.borderLineStyle = barLineStyle; 
    theLegend.cornerRadius = 10.0; 
    theLegend.swatchSize  = CGSizeMake(15.0, 15.0); 
    whiteTextStyle.fontSize = 13.0; 
    theLegend.textStyle  = whiteTextStyle; 
    theLegend.rowMargin  = 5.0; 
    theLegend.paddingLeft  = 10.0; 
    theLegend.paddingTop  = 10.0; 
    theLegend.paddingRight = 10.0; 
    theLegend.paddingBottom = 10.0; 
    graph.legend    = theLegend; 
    graph.legendAnchor  = CPTRectAnchorTopLeft; 
    graph.legendDisplacement = CGPointMake(80.0, -10.0); 
} 

- (void)createGraph 
{ 
    //Generate data 
    [self generateData]; 

    //Generate layout 
    [self generateLayout]; 
} 

- (void)dealloc 
{ 
    [data release]; 
    [super dealloc]; 
} 

#pragma mark - CPTPlotDataSource methods 

- (NSUInteger)numberOfRecordsForPlot:(CPTPlot *)plot 
{ 
    return dates.count; 
} 

- (double)doubleForPlot:(CPTPlot *)plot field:(NSUInteger)fieldEnum recordIndex:(NSUInteger)index 
{ 
    double num = NAN; 

    //X Value 
    if (fieldEnum == 0) { 
     num = index; 
    } 

    else { 
     double offset = 0; 
     if (((CPTBarPlot *)plot).barBasesVary) { 
      for (NSString *set in [[sets allKeys] sortedArrayUsingSelector:@selector(localizedCaseInsensitiveCompare:)]) { 
       if ([plot.identifier isEqual:set]) { 
        break; 
       } 
       offset += [[[data objectForKey:[dates objectAtIndex:index]] objectForKey:set] doubleValue]; 
      } 
     } 

     //Y Value 
     if (fieldEnum == 1) { 
      num = [[[data objectForKey:[dates objectAtIndex:index]] objectForKey:plot.identifier] doubleValue] + offset; 
     } 

     //Offset for stacked bar 
     else { 
      num = offset; 
     } 
    } 

    //NSLog(@"%@ - %d - %d - %f", plot.identifier, index, fieldEnum, num); 

    return num; 
} 

#pragma mark - CPTBarPlotDelegate methods 
-(void)barPlot:(CPTBarPlot *)plot barWasSelectedAtRecordIndex:(NSUInteger)index { 

    NSLog(@"barWasSelectedAtRecordIndex %d", index); 
} 


@end 

Answer 1

得到滾動，你需要設置globalXRange上plotspace是整個範圍，並設置xRange將是可見區域。

例如0-150的globalXRange和0-50的xRange。那麼你可以向上滾動查看51-150範圍。