CorePlot x軸定位問題

Question

在下面的代碼中，我嘗試添加5個自定義標籤並將其顯示在x軸上。但我面臨以下問題。我使用散點圖示例代碼來測試它。附上結果以及結果。

1. 並非所有5個標籤都顯示。
2. X軸標記從負側開始。所有x應該位於正面。
3. 在x軸上我想要 獲得與y軸相同的效果。同樣的灰色效果。

// Create graph from theme 
graph = [[CPTXYGraph alloc] initWithFrame:CGRectZero]; 
CPTTheme *theme = [CPTTheme themeNamed:kCPTDarkGradientTheme]; 
[graph applyTheme:theme]; 
CPTGraphHostingView *hostingView = (CPTGraphHostingView *)self.view; 
hostingView.collapsesLayers = NO; // Setting to YES reduces GPU memory usage, but can slow drawing/scrolling 
hostingView.hostedGraph  = graph; 

graph.paddingLeft = 10.0; 
graph.paddingTop = 10.0; 
graph.paddingRight = 10.0; 
graph.paddingBottom = 10.0; 

// Setup plot space 
CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *)graph.defaultPlotSpace; 
plotSpace.allowsUserInteraction = YES; 
plotSpace.yRange    = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(-80.0) length:CPTDecimalFromFloat(500.0)]; 
plotSpace.xRange    = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(-1) length:CPTDecimalFromFloat(15.0)]; 

CPTMutableLineStyle *xLineStyle = [CPTMutableLineStyle lineStyle]; 
xLineStyle.miterLimit  = 1.0f; 
xLineStyle.lineWidth   = 3.0f; 
xLineStyle.lineColor = [CPTColor whiteColor]; 
// Axes 
CPTXYAxisSet *axisSet = (CPTXYAxisSet *)graph.axisSet; 
CPTXYAxis *x   = axisSet.xAxis; 
x.visibleRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(0) length:CPTDecimalFromFloat(100)]; 
x.axisLineStyle    = xLineStyle; 
x.majorTickLineStyle   = xLineStyle; 
x.minorTickLineStyle   = xLineStyle; 
x.majorIntervalLength   = CPTDecimalFromString(@"1"); 
x.orthogonalCoordinateDecimal = CPTDecimalFromString(@"1"); 
x.titleLocation    = CPTDecimalFromFloat(0.5f); 
x.titleOffset     = 5.0f; 

x.labelingPolicy = CPTAxisLabelingPolicyNone; 
NSArray *customTickLocations = [NSArray arrayWithObjects:[NSDecimalNumber numberWithInt:1], [NSDecimalNumber numberWithInt:2], [NSDecimalNumber numberWithInt:3], [NSDecimalNumber numberWithInt:4], nil]; 
NSArray *xAxisLabels   = [NSArray arrayWithObjects:@"Label A", @"Label B", @"Label C", @"Label D", @"Label E", nil]; 
NSUInteger labelLocation  = 0; 
NSMutableArray *customLabels = [NSMutableArray arrayWithCapacity:[xAxisLabels count]]; 
for (NSNumber *tickLocation in customTickLocations) { 
    CPTAxisLabel *newLabel = [[CPTAxisLabel alloc] initWithText:[xAxisLabels objectAtIndex:labelLocation++] textStyle:x.labelTextStyle]; 
    newLabel.tickLocation = [tickLocation decimalValue]; 
    newLabel.offset  = x.labelOffset + x.majorTickLength; 
    newLabel.rotation  = M_PI/4; 
    [customLabels addObject:newLabel]; 
    [newLabel release]; 
} 

x.axisLabels = [NSSet setWithArray:customLabels]; 

CPTXYAxis *y = axisSet.yAxis; 
y.visibleRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(0) length:CPTDecimalFromFloat(500)]; 
y.majorIntervalLength   = CPTDecimalFromString(@"40"); 
y.minorTicksPerInterval  = 5; 
y.orthogonalCoordinateDecimal = CPTDecimalFromString(@"2"); 

y.delegate    = self; 

// Create a blue plot area 
CPTScatterPlot *boundLinePlot = [[[CPTScatterPlot alloc] init] autorelease]; 
CPTMutableLineStyle *lineStyle = [CPTMutableLineStyle lineStyle]; 
lineStyle.miterLimit  = 1.0f; 
lineStyle.lineWidth   = 3.0f; 
lineStyle.lineColor   = [CPTColor blueColor]; 
boundLinePlot.dataLineStyle = lineStyle; 
boundLinePlot.identifier = @"Blue Plot"; 
boundLinePlot.dataSource = self; 
[graph addPlot:boundLinePlot]; 

// Do a blue gradient 
CPTColor *areaColor1  = [CPTColor colorWithComponentRed:0.3 green:0.3 blue:1.0 alpha:0.8]; 
CPTGradient *areaGradient1 = [CPTGradient gradientWithBeginningColor:areaColor1 endingColor:[CPTColor clearColor]]; 
areaGradient1.angle = -90.0f; 
CPTFill *areaGradientFill = [CPTFill fillWithGradient:areaGradient1]; 
boundLinePlot.areaFill  = areaGradientFill; 
boundLinePlot.areaBaseValue = [[NSDecimalNumber zero] decimalValue]; 

// Add plot symbols 
CPTMutableLineStyle *symbolLineStyle = [CPTMutableLineStyle lineStyle]; 
symbolLineStyle.lineColor = [CPTColor blackColor]; 
CPTPlotSymbol *plotSymbol = [CPTPlotSymbol ellipsePlotSymbol]; 
plotSymbol.fill   = [CPTFill fillWithColor:[CPTColor blueColor]]; 
plotSymbol.lineStyle  = symbolLineStyle; 
plotSymbol.size   = CGSizeMake(10.0, 10.0); 
boundLinePlot.plotSymbol = plotSymbol; 

// Add some initial data 
NSMutableArray *contentArray = [[NSMutableArray alloc] init]; 
NSUInteger i; 
for (i = 0; i < 5; i++) { 

    id x = [NSNumber numberWithFloat:i]; 
    id y = [NSNumber numberWithFloat:200-i]; 
    [contentArray addObject:[NSMutableDictionary dictionaryWithObjectsAndKeys:x, @"x", y, @"y", nil]]; 
} 
self.dataForPlot = contentArray; 
[contentArray release]; 

Answer 1

1. 你只創建了四個標籤。 customTickLocations數組包含四個位置;爲每個位置創建一個標籤。

2. 標籤位於代碼中指定的位置。數據點位於（0,1,2,3,4），而標籤位於（1,2,3,4）。由於orthogonalCoordinateDecimal屬性設置的原因，y軸在x = 2處穿過x軸。

3. 如果要保留主題中的默認值，請不要在x軸上設置軸線或刻度線樣式。