UIPicker首先出现黑色

Question

我有以下代码来绘制自定义选择器。不幸的是，首次绘制的视图是黑色的。只有当我触摸它时才会出现。

我该如何解决这个问题？

以下是UIView中的相关代码：

- (void)drawRect:(CGRect)rect 
{
    [self createPicker];
    [self addSubview:dPicker];
//[dPicker reloadComponent:1];
}

-(void) createPicker
{
    dPicker = [[UIPickerView alloc] initWithFrame:CGRectZero];
    CGSize pickerSize = [dPicker sizeThatFits:CGSizeZero];
    dPicker.frame = [self pickerFrameWithSize:pickerSize];
    dPicker.delegate=self;
    dPicker.showsSelectionIndicator = YES;
    dPicker.hidden=NO;
}


- (CGRect)pickerFrameWithSize:(CGSize)size
{
    CGRect screenRect = [[UIScreen mainScreen] applicationFrame];
    CGRect pickerRect = CGRectMake( 0.0,
                               screenRect.size.height - 44.0 - size.height,
                               size.width,
                               size.height);
    return pickerRect;
}

Answer 1

修正了它。从UIViewController而不是UIView

调用子视图