比如
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
{
[self.pickerView removeFromSuperview];
self.pickerView = nil; //在这个函数中最尾部才能释放，不然会崩溃
int a = 1;
}
原文：http://www.cnblogs.com/huangzizhu/p/3945296.html