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我正在 iPhone 应用程序中创建一个饼图，它工作正常，但我还想显示每个部分的百分比，例如 17% 25% 等。

我正在使用以下代码

-(void)createGraph
{
    PieClass *myPieClass=[[PieClass alloc]initWithFrame:CGRectMake(50,440,320,230)];
    myPieClass.backgroundColor=[UIColor clearColor];
    myPieClass.itemArray=[[NSArray alloc]initWithObjects:valueOne,valueTwo,valueThree,valueFour, nil];
    myPieClass.myColorArray=[[NSArray alloc]initWithObjects:[UIColor blueColor],[UIColor redColor],[UIColor greenColor],[UIColor brownColor], nil];
    myPieClass.radius=100;
    [self.view addSubview:myPieClass];
}

馅饼类

   #import <UIKit/UIKit.h>
   @interface PieClass : UIView 
   {
          NSArray* itemArray;
          NSArray* myColorArray; 
          int radius;
   }

  @property(nonatomic,retain)NSArray* itemArray;
  @property(nonatomic,retain)NSArray* myColorArray;
  @property(nonatomic,assign) int radius;

  @end

  #import "PieClass.h"
  @implementation PieClass
  @synthesize itemArray,myColorArray,radius;

 - (id)initWithFrame:(CGRect)frame
 {
   self = [super initWithFrame:frame];
   if (self) {
    // Initialization code
   }
   return self;
 }

// 仅覆盖 drawRect: 如果您执行自定义绘图。// 空实现会对动画期间的性能产生不利影响。

 - (void)drawRect:(CGRect)rect
 {
   // Drawing code
   int c=[itemArray count];
   CGFloat angleArray[c];
   CGFloat offset;
   int sum=0;

   CGContextRef context = UIGraphicsGetCurrentContext();    
   CGContextSetAllowsAntialiasing(context, false);
   CGContextSetShouldAntialias(context, false);

   for(int i=0;i<[itemArray count];i++)
          sum+=[[itemArray objectAtIndex:i] intValue];

   for(int i=0;i<[itemArray count];i++)
   {
          angleArray[i]=(float)(([[itemArray objectAtIndex:i] intValue])/(float)sum)*(2*3.14); // in radians
           CGContextMoveToPoint(context, radius, radius);
           if(i==0)
               CGContextAddArc(context, radius, radius, radius, 0,angleArray[i], 0);
           else
               CGContextAddArc(context, radius, radius, radius,offset,offset+angleArray[i], 0);
           offset+=angleArray[i];

           CGContextSetFillColorWithColor(context, ((UIColor *)[myColorArray objectAtIndex:i]).CGColor);
           CGContextClosePath(context); 
           CGContextFillPath(context);
    }
 }
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