是否drawRect----泄漏内存

我目前看到内存泄漏的问题，它似乎来自这段代码：

- (void)drawRect:(CGRect)rect
{

    CGImageRef cgImage = CGBitmapContextCreateImage(offScreenBuffer);
    UIImage *uiImage = [[UIImage alloc] initWithCGImage:cgImage];

    CGImageRelease(cgImage);

    [uiImage drawInRect:self.bounds];
    [uiImage release];

}

该方法是从触摸事件调用的...

-(void)drawPoint:(UITouch *)touch {  

    currentLoc = [[PointLocation alloc] init];

    currentLoc.location = [touch locationInView:self];

    self.previousPoint = self.point;

    self.point = currentLoc;
    [self drawToBuffer];

    [currentLoc release];

}

这是绘制到缓冲区......

-(void)drawToBuffer {


    CGFloat color[4] = {R,G,B,A};

    if (self.previousPoint != nil) {
    CGContextSetRGBStrokeColor(offScreenBuffer, color[0],color[1],color[2],color[3]);

    CGContextBeginPath(offScreenBuffer);
    CGContextSetLineWidth(offScreenBuffer, lane);
    CGContextSetLineCap(offScreenBuffer, kCGLineCapRound);

    CGContextMoveToPoint(offScreenBuffer, previousPoint.location.x, previousPoint.location.y);
    CGContextAddLineToPoint(offScreenBuffer, point.location.x, point.location.y);

    CGContextDrawPath(offScreenBuffer, kCGPathStroke);

}
 [self setNeedsDisplay];

}

这真的很慢....:( 我不知道为什么...

每次我在选定的视图中绘制时，都会调用此方法，但每次我需要创建图像并将其显示在屏幕上时。有没有可能以另一种方式做到这一点？

在绘制矩形内发布的代码不应显示任何泄漏，因为图像已正确释放。