导航

core foundation type property

Posted on 2014-06-15 11:13  0304  阅读(254)  评论(0)  编辑  收藏  举报

class  have a property CGPathRef

define:

@property(asign)CGPathRef test;

need custom setTest method  and check NULL

 

 

 

https://developer.apple.com/library/mac/documentation/corefoundation/Reference/CFTypeRef/Reference/reference.html#//apple_ref/c/func/CFRelease

CFRelease

Releases a Core Foundation object.

void CFRelease (
   CFTypeRef cf
);
Parameters
cf A CFType object to release. This value must not be NULL

                      

CFRetain

Retains a Core Foundation object.

CFTypeRef CFRetain (
   CFTypeRef cf
);
Parameters
cf

The CFType object to retain. This value must not be NULL

CFGetRetainCount

Returns the reference count of a Core Foundation object.

CFIndex CFGetRetainCount (
   CFTypeRef cf
);
Parameters
cf

The CFType object to examine.

Return Value

A number representing the reference count of cf.

Discussion

You increment the reference count using the CFRetain function, and decrement the reference count using the CFRelease function.

This function may useful for debugging memory leaks. You normally do not use this function, otherwise.

demo CPTColor.h CPTColor.m

http://core-plot.googlecode.com/hg/documentation/html/iOS/_c_p_t_color_8h_source.html

https://github.com/core-plot/core-plot/blob/master/framework/Source/CPTColor.m

 

core foudation类型的变量一般都为只读，比如cgcolorRef，cgimageRef不是，在core plot中

CGImageRetain(null);会做NULL校验，而不是CFretain；

https://github.com/core-plot/core-plot/blob/master/framework/Source/CPTImage.m

http://core-plot.googlecode.com/hg/documentation/html/iOS/_c_p_t_image_8h_source.html

-(void)setImage:(CGImageRef)newImage
{
    if ( newImage != image ) {
        CGImageRetain(newImage);
        CGImageRelease(image);
        image = newImage;
    }
}
 
@property (nonatomic, readwrite, assign) CGImageRef image;
 
 

CGColorRetain

Increments the retain count of a Quartz color.

CGColorRef CGColorRetain (
   CGColorRef color
);
Parameters
color

The Quartz color to retain.

Return Value

The same color you passed in as the color parameter.

Discussion

This function is equivalent to CFRetain, except that it does not cause an error if the color parameter is NULL.

Availability
  • Available in OS X version 10.3 and later.
Related Sample Code
Declared In
CGColor.h

CGImageRetain

Increments the retain count of a bitmap image.

CGImageRef CGImageRetain (
   CGImageRef image
);
Parameters
image

The image to retain.

Return Value

The same image you passed in as the image parameter.

Discussion

This function is equivalent to CFRetain, except that it does not cause an error if the image parameter is NULL.

Availability
  • Available in iOS 2.0 and later.
Related Sample Code
Declared In
CGImage.h