#mark ---滚动弹幕 列表中留有7条记录 大于7条时删除并指引表视图向上滑动
- (void)addRowActionWithContent:(NSString *)str {
if (self.dataMutArray.count > 7) {
[self.dataMutArray removeLastObject];
[self.resultTableView deleteSections:[NSIndexSet indexSetWithIndex:self.dataMutArray.count - 1] withRowAnimation:(UITableViewRowAnimationNone)];
}
[self.dataMutArray insertObject:str atIndex:0];
[self.resultTableView insertSections:[NSIndexSet indexSetWithIndex:0] withRowAnimation:UITableViewRowAnimationTop];
[self.resultTableView setContentOffset:CGPointMake(0,0) animated:YES];
}