前些天遇到這樣一個需求，點擊cell的按鈕 需要上下移動該cell.在這里記錄一下 方便以后查閱.

效果是這樣的：

下面列出完成這個需求的過程 所注意的點：

1.實現(xiàn)點擊頂部按鈕、底部按鈕的action

W_S
    cell.upTapBlock = ^(UIButton *sender) {
        if (indexPath.row == 0) {
            return ;
        }
        //sourceIndexPath是被點擊cell的IndexPath
        NSIndexPath *sourceIndexPath = [NSIndexPath indexPathForRow:indexPath.row inSection:0];
        NSIndexPath *destinationIndexPath = [NSIndexPath indexPathForRow:indexPath.row - 1 inSection:0];

        [self.discussMutableMsgs exchangeObjectAtIndex:sourceIndexPath.row withObjectAtIndex:destinationIndexPath.row];
        //移動cell的位置
        [weakSelf.previewTable moveRowAtIndexPath:sourceIndexPath toIndexPath:destinationIndexPath];
        
        [weakSelf.previewTable reloadRowsAtIndexPaths:@[sourceIndexPath,destinationIndexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
        
    };

    
    cell.downTapBlock = ^(UIButton *sender) {
        if (indexPath.row == self.discussMutableMsgs.count - 1) {
            return ;
        }
        
        //sourceIndexPath是被點擊cell的IndexPath
        NSIndexPath *sourceIndexPath = [NSIndexPath indexPathForRow:indexPath.row inSection:0];
        NSIndexPath *destinationIndexPath = [NSIndexPath indexPathForRow:indexPath.row + 1 inSection:0];

        [self.discussMutableMsgs exchangeObjectAtIndex:sourceIndexPath.row withObjectAtIndex:destinationIndexPath.row];
        //移動cell的位置
        [weakSelf.previewTable moveRowAtIndexPath:sourceIndexPath toIndexPath:destinationIndexPath];
        
        [weakSelf.previewTable reloadRowsAtIndexPaths:@[sourceIndexPath,destinationIndexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
        
    };

2.注意通知系統(tǒng)哪些行可以移動
-(BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath{
    return YES;
}

還需要注意的是 cell 復(fù)用會造成bug，于是在給cell 綁定數(shù)據(jù)的時候 
[self.contentView removeAllSubviews];