众所周知，UITableView只有section和row,是没有多层级概念的。所以，想要做到像OA系统中的多级部门管理列表，就需要自己手动实现。
原理
tableView作为一个容器，每一行一个cell，点击一行cell时，去查找当前cell下的模型(model)的子模型数组，插入到当前模型下面，展示在界面上。隐藏时，再查找子模型数组删除。
数据模型
@property (nonatomic, copy ) NSString * title;
@property (nonatomic, assign) NSInteger level;
@property (nonatomic, strong) NSMutableArray * subItems;
@property (nonatomic, assign) BOOL isSubItemOpen;
@property (nonatomic, assign) BOOL isSubCascadeOpen;
isSubItemOpen标记当前cell展开或隐藏；isSubCascadeOpen标记该子菜单是否要在其父菜单展开时自动展开；level标记当前cell层级。
cell插入
#pragma mark - insert
- (NSArray *)insertMenuIndexPaths:(MyItem *)item {
NSArray *arr;
[treeItemsToInsert removeAllObjects];
[self insertMenuObject:item];
arr = [self insertIndexsOfMenuObject:treeItemsToInsert];
return arr;
}
//查找item下的所有需要插入的模型，临时保存到treeItemsToInsert数组中
- (void)insertMenuObject:(MyItem *)item {
if (item == nil) {
return ;
}
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:[self.tableViewData indexOfObject:item] inSection:0];
MyItem *childItem;
for (int i = 0; i < [item.subItems count]; i++) {
childItem = item.subItems[i];
[self.tableViewData insertObject:childItem atIndex:indexPath.row + i +1];
[treeItemsToInsert addObject:childItem];
item.isSubItemOpen = YES;
}
for (int i = 0; i < [item.subItems count]; i++) {
childItem = item.subItems[i];
if (childItem .isSubCascadeOpen) {
[self insertMenuObject:childItem];
}
}
}
//返回tableView需要插入的数组(indexPath路径)
- (NSArray *)insertIndexsOfMenuObject:(NSMutableArray *)array {
NSMutableArray *arr = [NSMutableArray array];
for (MyItem *item in array) {
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:[self.tableViewData indexOfObject:item] inSection:0];
[arr addObject:indexPath];
}
return arr;
}
cell删除
#pragma mark - delete
- (NSArray *)deleteMenuIndexPaths:(MyItem *)item {
NSArray * arr;
[treeItemsToRemove removeAllObjects];
[self deleteMenuObject:item];
arr = [self deleteIndexsOfMenuObject:treeItemsToRemove];
return arr;
}
//查找需要删除的模型数组
- (void) deleteMenuObject:(MyItem *)item {
if (item == nil)
{
return ;
}
MyItem *childItem;
for (int i = 0; i<[item.subItems count] && item.isSubItemOpen ; i++) {
childItem = [item.subItems objectAtIndex:i];
[self deleteMenuObject:childItem];
[treeItemsToRemove addObject:childItem];
// [tableViewData removeObject:childItem];
}
item.isSubItemOpen = NO;
return ;
}
//返回需要删除的indexpatn数组
- (NSArray *) deleteIndexsOfMenuObject:(NSMutableArray *)arr {
NSMutableArray *mutableArr;
mutableArr = [NSMutableArray array];
NSMutableIndexSet * set;
set = [NSMutableIndexSet indexSet];
for (int i = 0; i < [treeItemsToRemove count]; i++)
{
MyItem * item;
item = [treeItemsToRemove objectAtIndex:i];
NSIndexPath *path = [NSIndexPath indexPathForRow:[self.tableViewData indexOfObject:item] inSection:0];
[mutableArr addObject:path];
[set addIndex:path.row];
}
[self.tableViewData removeObjectsAtIndexes:set];
return mutableArr;
}
cell点击
#pragma mark - UITableViewDelegate
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
TableViewCell *cell = (TableViewCell *)[tableView cellForRowAtIndexPath:indexPath];
MyItem *item = cell.item;
if (item.isSubItemOpen) {
//删除
NSArray *arr = [self.menuData deleteMenuIndexPaths:item];
[self.tableView deleteRowsAtIndexPaths:arr withRowAnimation:UITableViewRowAnimationBottom];
} else {
//插入
NSArray *arr = [self.menuData insertMenuIndexPaths:item];
[self.tableView insertRowsAtIndexPaths:arr withRowAnimation:UITableViewRowAnimationBottom];
}
}
