iphone - 执行 CorePlot 代码时出现警告

Question

- (void)viewDidLoad
{
graph = [[CPTXYGraph alloc] initWithFrame: self.view.bounds];   
CPTGraphHostingView *hostingView = (CPTGraphHostingView *)self.view;
hostingView.hostedGraph = graph;
CPTPieChart *pieChart = [[CPTPieChart alloc] init];
pieChart.dataSource = self;
pieChart.pieRadius = 100.0;
pieChart.identifier = @"PieChart1";
pieChart.startAngle = M_PI_4;
pieChart.sliceDirection = CPTPieDirectionCounterClockwise;

self.pieData=   [NSMutableArray arrayWithObjects:[NSNumber numberWithDouble:90.0], 
                [NSNumber numberWithDouble:20.0],
                [NSNumber numberWithDouble:30.0],
                [NSNumber numberWithDouble:40.0],
                [NSNumber numberWithDouble:50.0], 
                [NSNumber numberWithDouble:60.0], nil];

CPTTheme *theme = [CPTTheme themeNamed:kCPTDarkGradientTheme];
[graph applyTheme:theme];
[graph addPlot:pieChart];
[pieChart release];
}

我在网上找到了这段代码。这段代码工作正常，但在
收到了两条警告 pieChart.dataSource = self;

它说。

warning: class 'SOTC_CorePlotExampleViewController' does not implement the 'CPTPlotDataSource' protocol

warning: Semantic Issue: Assigning to 'id' from incompatible type 'SOTC_CorePlotExampleViewController *'

Answer 1

添加<CPTPlotDataSource>到您的@interface (.h) 文件中自定义 View Controller 声明的末尾:

@interface YourViewController  : UIViewController <CPTPlotDataSource>

(将我示例中的 YourViewController 更改为您的 View Controller 的名称)