学步园

在非arc与arc的环境中使用时，导致程序crash.

 

//当前类使用－fno-objc 编译

    needle_ = [[MyView alloc] init];

    needleLayer = [CALayer layer];    
    needleLayer.delegate = self.needle;


- (void)dealloc
{    
    [needle_ release];
    [needleLayer release];
    [super dealloc];   //crash
}
    

 

 

-(void) drawLayer: (CALayer*) layer inContext: (CGContextRef) context  

 

he lightest-wight solution would be to create a small helper class in the the file as the UIView that's using the CALayer:

In MyView.h

@interfaceMyLayerDelegate:NSObject...@end

In MyView.m

@implementationMyLayerDelegate-(void)drawLayer:(CALayer*)layer inContext:(CGContextRef)ctx
{...}@end

Just place those at the top of your file, immediately below the #import directives. That way it feels more like using a "private class" to handle the drawing (although it isn't -- the delegate class can be instantiated by any code that imports the header).