Demo of using a program to draw a pie chart for ios

Demo function: Use a program to draw a pie chart demo.

Demo Description: draws a pie chart based on the given title array, value array, and color array. The main code is in CLMView. m.

Demo screenshot:

 

 

Demo main code: drawing part

[Csharp]
-(Void) drawRect :( CGRect) rect
{
CGContextRef context = UIGraphicsGetCurrentContext ();
// Cgcontextsets

// Anti-aliasing
CGContextSetAllowsAntialiasing (context, TRUE );

// Int arr [5] = {20, 15, 35, 85, 60 };

Float sum = 0;


For (int j = 0; j <[valueArr count]; j ++)
{
Sum + = [[valueArr objectAtIndex: j] floatValue];
}


CGContextMoveToPoint (context, 160,230 );

Float currentangel = 0;

// Pie chart
CGContextSaveGState (context );
CGContextScaleCTM (context, 1.0, scaleY );
 
Currentangel = 0;

For (int I = 0; I <[valueArr count]; I ++)
{
 
Float startAngle = KDGREED (currentangel );

Currentangel + = [[valueArr objectAtIndex: I] floatValue]/sum;

Float endAngle = KDGREED (currentangel );


// Draw the slice above
CGContextMoveToPoint (context, 160,230 );

[[ColorArr objectAtIndex: I % [valueArr count] setFill];

[[UIColor colorWithWhite: 1.0 alpha: 0.8] setStroke];

CGContextAddArc (context, 160,230,150, startAngle, endAngle, 0 );

CGContextClosePath (context );
CGContextDrawPath (context, kCGPathFill );



// Draw the side
Float starx = cos (startAngle) × 150 + 160;
Float stary = sin (startAngle) × 150 + 230;

Float endx = cos (endAngle) * 150 + 160;
Float endy = sin (endAngle) * 150 + 230;

// Float starty1 = stary + spaceHeight;
Float endy1 = endy + spaceHeight;


If (endAngle <K_PI)
{
}

// Only a radian of 3.14 can draw the thickness of the front.
Else if (startAngle <K_PI)
{
EndAngle = K_PI;
Endx = 10;
Endy1 = 230 + spaceHeight;
}

Else
Break;


// CGContextSetBlendMode (context, kCGBlendModeMultiply );


// Draw the thickness
CGMutablePathRef path = CGPathCreateMutable ();
CGPathMoveToPoint (path, nil, starx, stary );
CGPathAddArc (path, nil, 160,230,150, startAngle, endAngle, 0 );
CGPathAddLineToPoint (path, nil, endx, endy1 );

CGPathAddArc (path, nil, 160,230 + spaceHeight, 150, endAngle, startAngle, 1 );
CGContextAddPath (context, path );

[[ColorArr objectAtIndex: I % [valueArr count] setFill];
[[UIColor colorWithWhite: 0.9 alpha: 1.0] setStroke];

CGContextDrawPath (context, kCGPathFill );

[[UIColor colorWithWhite: 0.1 alpha: 0.4] setFill];
CGContextAddPath (context, path );
CGContextDrawPath (context, kCGPathFill );

 
}


// Overall gradient
CGFloat componets [] = {0.0, 0.0, 0.0, 0.5, 0.0, 0.0, 0.0, 0.1 };

CGColorSpaceRef colorspace = CGColorSpaceCreateDeviceRGB ();

CGGradientRef gradient = CGGradientCreateWithColorComponents (colorspace, componets, nil, 2 );

CGContextDrawRadialGradient (context, gradient, CGPointMake (160,230), 0, CGPointMake (160,230), 150, 0 );

CFRelease (colorspace );
CGGradientRelease (gradient );


CGContextRestoreGState (context );

// Draw text

For (int I = 0; I <[valueArr count]; I ++)
{
Float origionx = 50;
Float origiony = I * 30 + 200;

[[ColorArr objectAtIndex: I % [valueArr count] setFill];

CGContextFillRect (context, CGRectMake (origionx, origiony, 20, 20 ));
CGContextDrawPath (context, kCGPathFill );


If (I <[titleArr count])
{
NSString * title = [titleArr objectAtIndex: I];
[Title drawAtPoint: CGPointMake (origionx + 50, origiony) withFont: [UIFont systemFontOfSize: 16];
}

}

}

-(Void) drawRect :( CGRect) rect
{
CGContextRef context = UIGraphicsGetCurrentContext ();
// Cgcontextsets
 
// Anti-aliasing
CGContextSetAllowsAntialiasing (context, TRUE );
 
// Int arr [5] = {20, 15, 35, 85, 60 };
 
Float sum = 0;
 
 
For (int j = 0; j <[valueArr count]; j ++)
{
Sum + = [[valueArr objectAtIndex: j] floatValue];
}
 
 
CGContextMoveToPoint (context, 160,230 );
 
Float currentangel = 0;
 
// Pie chart
CGContextSaveGState (context );
CGContextScaleCTM (context, 1.0, scaleY );

Currentangel = 0;
 
For (int I = 0; I <[valueArr count]; I ++)
{

Float startAngle = KDGREED (currentangel );

Currentangel + = [[valueArr objectAtIndex: I] floatValue]/sum;

Float endAngle = KDGREED (currentangel );


// Draw the slice above
CGContextMoveToPoint (context, 160,230 );

[[ColorArr objectAtIndex: I % [valueArr count] setFill];

[[UIColor colorWithWhite: 1.0 alpha: 0.8] setStroke];

CGContextAddArc (context, 160,230,150, startAngle, endAngle, 0 );

CGContextClosePath (context );
CGContextDrawPath (context, kCGPathFill );



// Draw the side
Float starx = cos (startAngle) × 150 + 160;
Float stary = sin (startAngle) × 150 + 230;

Float endx = cos (endAngle) * 150 + 160;
Float endy = sin (endAngle) * 150 + 230;

// Float starty1 = stary + spaceHeight;
Float endy1 = endy + spaceHeight;


If (endAngle <K_PI)
{
}

// Only a radian of 3.14 can draw the thickness of the front.
Else if (startAngle <K_PI)
{
EndAngle = K_PI;
Endx = 10;
Endy1 = 230 + spaceHeight;
}

Else
Break;


// CGContextSetBlendMode (context, kCGBlendModeMultiply );


// Draw the thickness
CGMutablePathRef path = CGPathCreateMutable ();
CGPathMoveToPoint (path, nil, starx, stary );
CGPathAddArc (path, nil, 160,230,150, startAngle, endAngle, 0 );
CGPathAddLineToPoint (path, nil, endx, endy1 );

CGPathAddArc (path, nil, 160,230 + spaceHeight, 150, endAngle, startAngle, 1 );
CGContextAddPath (context, path );

[[ColorArr objectAtIndex: I % [valueArr count] setFill];
[[UIColor colorWithWhite: 0.9 alpha: 1.0] setStroke];

CGContextDrawPath (context, kCGPathFill );

[[UIColor colorWithWhite: 0.1 alpha: 0.4] setFill];
CGContextAddPath (context, path );
CGContextDrawPath (context, kCGPathFill );

}
 

// Overall gradient
CGFloat componets [] = {0.0, 0.0, 0.0, 0.5, 0.0, 0.0, 0.0, 0.1 };
 
CGColorSpaceRef colorspace = CGColorSpaceCreateDeviceRGB ();
 
CGGradientRef gradient = CGGradientCreateWithColorComponents (colorspace, componets, nil, 2 );
 
CGContextDrawRadialGradient (context, gradient, CGPointMake (160,230), 0, CGPointMake (160,230), 150, 0 );
 
CFRelease (colorspace );
CGGradientRelease (gradient );
 
 
CGContextRestoreGState (context );
 
// Draw text
 
For (int I = 0; I <[valueArr count]; I ++)
{
Float origionx = 50;
Float origiony = I * 30 + 200;

[[ColorArr objectAtIndex: I % [valueArr count] setFill];

CGContextFillRect (context, CGRectMake (origionx, origiony, 20, 20 ));
CGContextDrawPath (context, kCGPathFill );


If (I <[titleArr count])
{
NSString * title = [titleArr objectAtIndex: I];
[Title drawAtPoint: CGPointMake (origionx + 50, origiony) withFont: [UIFont systemFontOfSize: 16];
}

}
 
}

 

 

Call method of CLMView. m:

 

[Csharp]
CLMView * cv = [[CLMView alloc] initWithFrame: CGRectMake (0, 0,320,440)]; // instantiate
 
// Specify the title Array
Cv. titleArr = [NSArray arrayWithObjects: @ "iphone", @ "sybian", @ "windowbile", @ "mego", @ "android", nil];
 
// Array of specified numeric ratios
Cv. valueArr = [NSArray arrayWithObjects: [NSNumber numberWithFloat: 20], [NSNumber numberWithFloat: 20], \
[NSNumber numberWithFloat: 20], [NSNumber numberWithFloat: 20], [NSNumber numberWithFloat: 20], nil];
// Specify the color array
Cv. colorArr = [NSArray arrayWithObjects: [UIColor yellowColor], [UIColor blueColor], [UIColor brownColor], [UIColor purpleColor], [UIColor orangeColor], nil];

[Self. view addSubview: cv];
[Cv release];

CLMView * cv = [[CLMView alloc] initWithFrame: CGRectMake (0, 0,320,440)]; // instantiate

// Specify the title Array
Cv. titleArr = [NSArray arrayWithObjects: @ "iphone", @ "sybian", @ "windowbile", @ "mego", @ "android", nil];

// Array of specified numeric ratios
Cv. valueArr = [NSArray arrayWithObjects: [NSNumber numberWithFloat: 20], [NSNumber numberWithFloat: 20], \
[NSNumber numberWithFloat: 20], [NSNumber numberWithFloat: 20], [NSNumber numberWithFloat: 20], nil];
// Specify the color array
Cv. colorArr = [NSArray arrayWithObjects: [UIColor yellowColor], [UIColor blueColor], [UIColor brownColor], [UIColor purpleColor], [UIColor orangeColor], nil];
 
[Self. view addSubview: cv];
[Cv release];