问题描述
很抱歉有关iPhone和Quartz编程的愚蠢问题。刚刚开始从C ++转换为Objective-C:)
Sorry for noobish question about iPhone and Quartz programming. Just started my conversion from C++ to Objective-C :)
所以,我有这样的类方法
So, I have such a class method
+(CGGradientRef)CreateGradient:(UIColor*)startColor endColor:(UIColor*)endColor
{
CGGradientRef result;
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
CGFloat locations[2] = {0.0f, 1.0f};
CGFloat startRed, startGreen, startBlue, startAlpha;
CGFloat endRed, endGreen, endBlue, endAlpha;
[endColor getRed:&endRed green:&endGreen blue:&endBlue alpha:&endAlpha];
[startColor getRed:&startRed green:&startGreen blue:&startBlue alpha:&startAlpha];
CGFloat componnents[8] = {
startRed, startGreen, startBlue, startAlpha,
endRed, endGreen, endBlue, endAlpha
};
result = CGGradientCreateWithColorComponents(colorSpace, componnents, locations, 2);
CGColorSpaceRelease(colorSpace);
return result;
}
及其使用情况。
-(void)FillGradientRect:(CGRect)area startColor:(UIColor *)startColor endColor:(UIColor *)endColor isVertical:(BOOL)isVertical
{
CGContextRef context = UIGraphicsGetCurrentContext();
UIGraphicsPushContext(context);
CGGradientRef gradient = [Graphics CreateGradient:startColor endColor:endColor];
CGPoint startPoint, endPoint;
if (isVertical) {
startPoint = CGPointMake(CGRectGetMinX(area), area.origin.y);
endPoint = CGPointMake(startPoint.x, area.origin.y + area.size.height);
}else{
startPoint = CGPointMake(0, area.size.height / 2.0f);
endPoint = CGPointMake(area.size.width, startPoint.y);
}
CGContextDrawLinearGradient(context, gradient, startPoint, endPoint, 0);
CGGradientRelease(gradient);
UIGraphicsPopContext();
}
一切都按预期工作。但是,当我从Xcode 4运行Analyze工具时,我收到一个关于 CreateGradient 的结果
变量的内存泄漏的警告。好吧,我理解那是什么,但在我的调用方法中,我正在释放渐变对象( CGGradientRelease(gradient);
)。
那么,谁错了,如何让Analyze工具开心?
everything works as expected. But, when I run the Analyze tool from Xcode 4, I'm getting a warning about memory leak in method CreateGradient for result
variable. Well, I understand what's that about, but in my calling method I'm releasing the gradient object (CGGradientRelease(gradient);
).So, who is wrong and how to make Analyze tool happy?
Thx
推荐答案
由于CGGradientRef是Core Foundation类型的对象,你可以自动发布它。只需在返回渐变之前添加此行:
Since CGGradientRef is a Core Foundation type of object, you can autorelease it. Just add this line before returning the gradient:
[(id)result autorelease];
这篇关于为方法创建渐变和返回的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!