点击UITableView空白位置收起键盘

-(void)addHideKeyboard
{
    UITapGestureRecognizer *gestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(hideKeyboard)];
    [self addGestureRecognizer:gestureRecognizer];
    gestureRecognizer.cancelsTouchesInView = NO;
}

- (void) hideKeyboard {
    [self endEditing:YES];
}