关键词：递归 多级菜单 复选
目标：
1.显示多级菜单，默认显示一级.
2.可以通过点击有子级的行展开菜单
3.通过复选框，改变选中状态。状态有全选、半选、未选中
4.可以扩展获取当前所选的条目集合
menu.gif
实现过程：
数据处理
1.首先根Datasource进行数据处理
2.生成一个handler:MultilevelDataHandler 将数据处理逻辑在handle处理，将数据处理隔离
MultilevelDataHandler *dataHandler = [MultilevelDataHandler sharedHandler];
[dataHandler setLevelKeys:@[@"second_category", @"knowledge"]]; //由于源数据中每层数据可能采用不同的key，所有我把每层的key依次添加到数组里面，以便数据转化
[dataHandler setReDataSource:dataSource]; // 将源数据交给handle处理
3.建立一个数据模型，需要用一些属性记录层级关系。最后我用了一个字典来记录原始的数据信息。
//
// MultilevelMenuModel.h
// MultilevelMenuWithCheckbox
//// Created by hyt on 2017/10/31.
// Copyright © 2017年 hyt. All rights reserved.
//#importtypedef NS_ENUM (NSInteger, MMSelectState){
selectNone,
selectHalf,
selectAll
};
@interface MultilevelMenuModel : NSObject
@property (nonatomic, assign) NSInteger MMLevel;
@property (nonatomic, assign) NSInteger MMIndex;
//@property (nonatomic, assign) NSInteger MMSuperIndex;
@property (nonatomic, strong) NSMutableArray *locationArray;
@property (nonatomic, strong) NSArray *MMSubArray;
@property (nonatomic, assign) MMSelectState MMSelectState;
@property (nonatomic, assign) BOOL MMIsOpen;
@property (nonatomic, strong) NSDictionary *dataDict; // original data
@end
这里是Demo的数据Json
json数据：
[{
"id": "",
"name": "",
"type": "",
"second_category": [{
"id": "",
"name": "",
"type": "",
"knowledge": [{
"id": "",
"name": "",
"type": ""
}]
}]
}]
4.将jsonDictionary转化成数据模型的时候，把层级关系也一并赋值。
由于数据层级数量的不确定性，这里用递归的方式把每层的数据结构都放到其父类的subArray当中。
- (MultilevelMenuModel *)getModelByDict:(NSDictionary *)dict
modelLevel:(NSInteger)level
modelIndex:(NSInteger)index
superIndex:(NSInteger)superIndex
locationArray:(NSMutableArray *)loactionArray{
MultilevelMenuModel *levelModel = [[MultilevelMenuModel alloc] init];
levelModel.MMLevel = level;
levelModel.MMIndex = index++;
// levelModel.MMSuperIndex = superIndex;
levelModel.dataDict = [NSDictionary dictionaryWithDictionary:dict];
levelModel.locationArray = [NSMutableArray arrayWithArray:loactionArray];
[levelModel.locationArray addObject:[NSNumber numberWithInteger:superIndex]];
if ([self checkModelHasSubArray:levelModel]) {
[self setModelSubArray:levelModel];
}
return levelModel;
}
- (void)setModelSubArray:(MultilevelMenuModel *)model {
NSString *key = [self getSubKeyByModel:model];
NSArray *subDictArray = model.dataDict[key];
model.MMSubArray = [self getModelArrayFromDictArray:subDictArray
modelLevel:model.MMLevel + 1
superIndex:model.MMIndex
locationArray:model.locationArray];
}
- (NSArray *)getModelArrayFromDictArray:(NSArray *)dictArray
modelLevel:(NSInteger)level
superIndex:(NSInteger)superIndex
locationArray:(NSMutableArray *)locationArray{
NSMutableArray *deArray = [NSMutableArray array];
NSInteger index = 0;
for (NSDictionary *dict in dictArray) {
MultilevelMenuModel *levelModel = [self getModelByDict:dict
modelLevel:level
modelIndex:index++
superIndex:superIndex
locationArray:locationArray];
[deArray addObject:levelModel];
}
return [NSArray arrayWithArray:deArray];
}
5.建一个新的数组用来存储要在tableView上展示的数据模型，按照父类子类，父类子类的顺序排列。我这里默认是把第一级全部关闭展示的
6.实现菜单展开关闭功能
根据点击的model的isOpen属性来判断是否展开。
展开时是把subArray中的子级添加到showData当中去，需注意判断子级当前的状态是否是已展开的，如果是的话需要递归调用展开方法。
关闭时是把subArray中的子级从showData中删除，也用递归的方法把子类的子类也一并删除。
删除子级的时候不影响子级的展开状态。
- (void)addSubModelToShowByModel:(MultilevelMenuModel *)superModel {
NSInteger superIndex = [self.showData indexOfObject:superModel]; //
for (MultilevelMenuModel *subModel in [[superModel.MMSubArray reverseObjectEnumerator] allObjects]) {
if (![self.showData containsObject:subModel]) {
[self.showData insertObject:subModel atIndex:superIndex + 1];
}
if (subModel.MMIsOpen == YES && subModel.MMSubArray.count > 0 ) {
[self addSubModelToShowByModel:subModel];
}
}
superModel.MMIsOpen = YES;
}
- (void)removeSubModelFromShowByModel:(MultilevelMenuModel *)superModel
closeIt:(BOOL)close{
if (superModel.MMSubArray.count == 0) {
return;
}
for (MultilevelMenuModel *subModel in superModel.MMSubArray) {
[self removeSubModelFromShowByModel:subModel closeIt:!subModel.MMIsOpen];
[self.showData removeObject:subModel];
}
superModel.MMIsOpen = !close;
}
7.实现复选框功能
用三个方法分别实现复修改选框的三种状态
每个方法中，都需要考虑当前model的状态改变对其父级与子级的影响
用model的subArray找到其子级，用locationArray记录的坐标找到其父类
父级和子级的状态改变也会影响到他们的父级和子级，所有用递归的方式修改状态
- (void)setModelToBeStateNone:(MultilevelMenuModel *)model {
// make current model unselected
model.MMSelectState = selectNone;
// make sublevel unselected
if (model.MMSubArray.count > 0) {
for (MultilevelMenuModel *subModel in model.MMSubArray) {
if (subModel.MMSelectState != selectNone) {
[self setModelToBeStateNone:subModel];
}
}
}
//make super model unselected
MultilevelMenuModel *supModel = [self findSuperModelBySubModel:model];
if (supModel == nil) {
return;
}
if ([self checkSubModeHasStateAll:supModel]) {
[self setModelToBeStateHalf:supModel];
} else if ([self checkSubModelHasSelected:supModel]) {
[self setModelToBeStateHalf:supModel];
} else {
supModel.MMSelectState = selectNone;
}
}
- (void)setModelToBeStateHalf:(MultilevelMenuModel *)model {
// make current model selected
model.MMSelectState = selectHalf;
//make super model half-selected
MultilevelMenuModel *supModel = [self findSuperModelBySubModel:model];
if (supModel == nil) {
return;
}
[self setModelToBeStateHalf:supModel];
}
- (void)setModelToBeStateAll:(MultilevelMenuModel *)model {
// make current model selected
model.MMSelectState = selectAll;
// make sublevel selected
if (model.MMSubArray.count > 0) {
for (MultilevelMenuModel *subModel in model.MMSubArray) {
if (subModel.MMSelectState != selectAll) {
[self setModelToBeStateAll:subModel];
}
}
}
//make super model selected
MultilevelMenuModel *supModel = [self findSuperModelBySubModel:model];
if (supModel == nil) {
return;
}
if ([self checkSubModelsBeStateAll:supModel]) {
[self setModelToBeStateAll:supModel];
} else {
[self setModelToBeStateHalf:supModel];
}
}
根据locationArray里记录的每一层父级的序号，找到当前model的父级
- (MultilevelMenuModel *)findSuperModelBySubModel:(MultilevelMenuModel *)subModel {
NSArray *location = subModel.locationArray;
if (location.count == 0) {
return nil;
}
MultilevelMenuModel *resultModel;
NSArray *dataSource = self.modelArray;
int i = 1;
while (i < location.count) {
int index = [location[i] intValue];
resultModel = dataSource[index];
dataSource = resultModel.MMSubArray;
i++;
}
return resultModel;
}
小结
由于层级数量的不确定性，所以多次使用到了递归的方式。要注意递归的结束条件，必须陷入死循环当中。
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