为什么uiimage的drawAtpoint在此代码中引发错误?

我正在我的iPhone AAP中创建自定义手机,我也在向其添加图像,但我继续在[图像绘制点:p]处出错;

错误状态 ***-[uiimage drawAtpoint:]:消息发送到已解除分配的实例0x45cb1f0

我的代码是

-(void)setImage:(UIImage *)i
{
    //[image release];
    image = i;
    [self setNeedsDisplay]; 
}

- (void)setNeedsDisplay
{
    [super setNeedsDisplay];
    [contentView setNeedsDisplay];
}

- (void)drawContentView:(CGRect)r
{
    CGContextRef context = UIGraphicsGetCurrentContext();

    UIColor *backgroundColor = [UIColor yellowColor];
    UIColor *textColor = [UIColor blackColor];

    if(self.selected)
    {
        backgroundColor = [UIColor clearColor];
        textColor = [UIColor whiteColor];
    }

    [backgroundColor set];
    CGContextFillRect(context, r);

    CGPoint p;
    p.x = 3;
    p.y = 3;

    [textColor set];
    UIImage *image2 = image;
    [image2 drawAtPoint:p];

    p.x += 70; // space between words
    [text2 drawAtPoint:p withFont:firstTextFont];

    //[image release];
}