在 iPhone 应用程序中未显示的视图

Posted 2023-02-26

【中文标题】在 iPhone 应用程序中未显示的视图

【英文标题】：View Not Showing Up in iPhone App

【发布时间】：2012-07-24 11:57:18

【问题描述】：

我有 4 个文件，BarPlot.h 和 BarPlot.m，BarPlotViewController.h 和 BarPlotViewController.m 我的（对你们来说可能非常直截了当）是我无法让 BarplotViewController 显示我的图表。

我已确保在情节提要中调用了正确的视图控制器。

我已经多次查看代码，但我无法弄清楚为什么当我在模拟器中运行应用程序时视图没有显示..

我已包含以下文件。

非常感谢任何和所有帮助。

BarPlotViewController.h

#import <UIKit/UIKit.h>
#import "CorePlot-CocoaTouch.h"
#import "BarPlot.h"

@interface BarPlotViewController : UIViewController 
    CPTGraphHostingView *_graphHostingView;


@property (nonatomic, retain) BarPlot *barPlot;

@end

BarPlotViewController.m

#import "BarPlotViewController.h"

@implementation BarPlotViewController
@synthesize barPlot = _barPlot;


- (void)viewWillAppear:(BOOL)animated
   
    self.barPlot = [[BarPlot alloc] initWithHostingView:_graphHostingView];
    [self.barPlot generateBarPlot];


@end

条形图.h

#import <UIKit/UIKit.h>
#import "CorePlot-CocoaTouch.h"

@interface BarPlot : UIViewController <CPTBarPlotDataSource, CPTBarPlotDelegate> 
    CPTGraphHostingView *_hostingView;  
CPTXYGraph *_graph;


@property (nonatomic, retain) NSMutableArray *data;
@property (nonatomic, retain) CPTGraphHostingView *hostingView;
@property (nonatomic, retain) CPTXYGraph *graph;


// Methods to create this object and attach it to it's hosting view.
-(id)initWithHostingView:(CPTGraphHostingView *)hostingView;


// Generate the bar plot
- (void) generateBarPlot;

@end

条形图.m

#import "BarPlot.h"

@implementation BarPlot

#define BAR_POSITION @"POSITION"
#define BAR_HEIGHT @"HEIGHT"
#define COLOR @"COLOR"
#define CATEGORY @"CATEGORY"

#define AXIS_START 0
#define AXIS_END 50

@synthesize data;
@synthesize hostingView = _hostingView;
@synthesize graph = _graph;


// Initialise the bar plot in the provided hosting
-(id)initWithHostingView:(CPTGraphHostingView *)hostingView

    self = [super init];

if ( self != nil ) 
    self.hostingView = hostingView;
    self.graph = nil;



NSLog(@"Bar Plot: I'm in the initWithHostingView (in the barplot.m file)");

return self;



- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil

self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) 

    self.data = [NSMutableArray array];

    int bar_heights[] = 20,30;


    UIColor *colors[] = 
        [UIColor redColor],
        [UIColor blueColor],
        [UIColor orangeColor],
        [UIColor purpleColor];


    NSString *categories[] = @"", @"";



    for (int i = 0; i < 2 ; i++)
        double position = i*20; //Bars will be 10 pts away from each other
        double height = bar_heights[i];

        NSDictionary *bar = [NSDictionary dictionaryWithObjectsAndKeys:
                             [NSNumber numberWithDouble:position],BAR_POSITION,
                             [NSNumber numberWithDouble:height],BAR_HEIGHT,
                             colors[i],COLOR,
                             categories[i],CATEGORY,
                             nil];
        [self.data addObject:bar];

    
    [self generateBarPlot];

return self;



- (void)generateBarPlot

//Create host view
/*self.hostingView = [[CPTGraphHostingView alloc] 
                    initWithFrame:[[UIScreen mainScreen]bounds]];
[self.view addSubview:self.hostingView];



//Create graph and set it as host view's graph
self.graph = [[CPTXYGraph alloc] initWithFrame:self.hostingView.bounds];
[self.hostingView setHostedGraph:self.graph];*/



// Create a graph object which we will use to host just one scatter plot.
CGRect frame = [self.hostingView bounds];
self.graph = [[CPTXYGraph alloc] initWithFrame:frame];

// Tie the graph we've created with the hosting view.
self.hostingView.hostedGraph = self.graph;



//set graph padding and theme
self.graph.plotAreaFrame.paddingTop = 20.0f;
self.graph.plotAreaFrame.paddingRight = 20.0f;
self.graph.plotAreaFrame.paddingBottom = 70.0f;
self.graph.plotAreaFrame.paddingLeft = 70.0f;
[self.graph applyTheme:[CPTTheme themeNamed:kCPTDarkGradientTheme]];



// Gets rid of decimal on years
NSNumberFormatter *labelFormatter = [[NSNumberFormatter alloc] init];
labelFormatter.maximumFractionDigits = 0;



//set axes ranges
CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *)self.graph.defaultPlotSpace;
plotSpace.xRange = [CPTPlotRange plotRangeWithLocation:
                    CPTDecimalFromFloat(AXIS_START)
                                                length:CPTDecimalFromFloat((AXIS_END - AXIS_START))];
plotSpace.yRange = [CPTPlotRange plotRangeWithLocation:
                    CPTDecimalFromFloat(AXIS_START)
                                                length:CPTDecimalFromFloat((AXIS_END - AXIS_START))];




CPTXYAxisSet *axisSet = (CPTXYAxisSet *)self.graph.axisSet;
//set axes' title, labels and their text styles
CPTMutableTextStyle *textStyle = [CPTMutableTextStyle textStyle];
textStyle.fontName = @"Helvetica";
textStyle.fontSize = 14;
textStyle.color = [CPTColor whiteColor];



axisSet.xAxis.title = @"A";
axisSet.yAxis.title = @"B";
axisSet.xAxis.titleTextStyle = textStyle;
axisSet.yAxis.titleTextStyle = textStyle;
axisSet.xAxis.titleOffset = 30.0f;
axisSet.yAxis.titleOffset = 40.0f;
axisSet.xAxis.labelTextStyle = textStyle;
axisSet.yAxis.labelTextStyle = textStyle;
axisSet.xAxis.labelOffset = 3.0f;
axisSet.yAxis.labelOffset = 3.0f;



//set axes' line styles and interval ticks
CPTMutableLineStyle *lineStyle = [CPTMutableLineStyle lineStyle];
lineStyle.lineColor = [CPTColor whiteColor];
lineStyle.lineWidth = 3.0f;
axisSet.xAxis.axisLineStyle = lineStyle;
axisSet.yAxis.axisLineStyle = lineStyle;
axisSet.xAxis.majorTickLineStyle = lineStyle;
axisSet.yAxis.majorTickLineStyle = lineStyle;
axisSet.xAxis.majorIntervalLength = CPTDecimalFromFloat(5.0f);
axisSet.yAxis.majorIntervalLength = CPTDecimalFromFloat(5.0f);
axisSet.xAxis.majorTickLength = 10.0f;
axisSet.yAxis.majorTickLength = 10.0f;
axisSet.xAxis.minorTickLineStyle = lineStyle;
axisSet.yAxis.minorTickLineStyle = lineStyle;
axisSet.xAxis.minorTicksPerInterval = 1;
axisSet.yAxis.minorTicksPerInterval = 1;
axisSet.xAxis.minorTickLength = .0f;
axisSet.yAxis.minorTickLength = .0f;
axisSet.xAxis.labelFormatter = labelFormatter;
axisSet.yAxis.labelFormatter = labelFormatter;



// Create bar plot and add it to the graph
CPTBarPlot *plot = [[CPTBarPlot alloc] init] ;
plot.delegate = self;
plot.dataSource = self;
plot.barWidth = [[NSDecimalNumber decimalNumberWithString:@"5.0"]
                 decimalValue];
plot.barOffset = [[NSDecimalNumber decimalNumberWithString:@"10.0"]
                  decimalValue];
plot.barCornerRadius = 5.0;



// Remove bar outlines
CPTMutableLineStyle *borderLineStyle = [CPTMutableLineStyle lineStyle];
borderLineStyle.lineColor = [CPTColor clearColor];
plot.lineStyle = borderLineStyle;



// Identifiers are handy if you want multiple plots in one graph
plot.identifier = @"chocoplot";
[self.graph addPlot:plot];




-(NSUInteger)numberOfRecordsForPlot:(CPTPlot *)plot

if ( [plot.identifier isEqual:@"chocoplot"] ) 

    return [self.data count];


return 0;




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

if ( [plot.identifier isEqual:@"chocoplot"] )


    NSDictionary *bar = [self.data objectAtIndex:index];


    if( fieldEnum == 2 ) 
        return [bar valueForKey:BAR_POSITION];
        //return [NSNumber numberWithDouble:20];
    
    else if( fieldEnum == 3 ) 
        return [bar valueForKey:BAR_HEIGHT];
        //return [NSNumber numberWithDouble:20];
    


NSLog(@"numberForPlot return before");
return [NSNumber numberWithDouble:15];


@end

【问题讨论】：

您需要将_graphHostingView 视图作为子视图添加到self.view 中

很抱歉，您能告诉我具体的代码以及在哪里插入吗？我在这里尝试但没有成功。

【参考方案1】：

嗯，我注意到的第一件事是你从不调用 addSubview。那是实际上“添加视图”的代码，所以我将从那里开始。另外，看到这个问题，第二个答案看起来可能会有所帮助：Adding CPTGraphHostingView as a subview

【讨论】：

我正在阅读，谢谢。很有帮助，但是可以告诉我在哪里添加子视图吗？

我不确定在哪里添加它。您在 generateBarPlot 下注释掉的代码怎么样？那不行吗？此外，这也可能有所帮助：***.com/questions/7645935/…

这是我一直在努力的代码。你能告诉我要添加的确切代码吗？到目前为止，我不确定我是否在尝试调用正确的视图/变量。我也许能弄清楚自己在哪里。