[UIKBBlurredKeyView candidateList]: unrecognized

出现crash原因：

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
         [[self nextResponder] touchesBegan:touches withEvent:event];
         if ([super respondsToSelector:@selector(touchesBegan:withEvent:)]) {
             [super touchesBegan:touches withEvent:event];
         }
}

解决方案：

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    if ([self isMemberOfClass:[UIScrollView class]]) {
         [[self nextResponder] touchesBegan:touches withEvent:event];
         if ([super respondsToSelector:@selector(touchesBegan:withEvent:)]) {
             [super touchesBegan:touches withEvent:event];
         }
    }
}