您好,登錄后才能下訂單哦!
本篇文章為大家展示了怎么在iOS中實(shí)現(xiàn)一個(gè)三級(jí)聯(lián)動(dòng)選擇器,內(nèi)容簡明扼要并且容易理解,絕對(duì)能使你眼前一亮,通過這篇文章的詳細(xì)介紹希望你能有所收獲。
1)怎么設(shè)置默認(rèn)值,關(guān)鍵代碼
[self.pickerView selectRow:xxx inComponent:xxx animated:YES];
2)怎么讓三級(jí)之間聯(lián)動(dòng) ,關(guān)鍵代碼
[self pickerView:self.pickerView didSelectRow:0 inComponent:0 ];//聯(lián)動(dòng)輪子1 必須得本輪有數(shù)據(jù)后觸發(fā)否則crash
先看下效果圖
關(guān)于設(shè)置默認(rèn)值,三級(jí)聯(lián)動(dòng),用UIPickView的話就是有3個(gè)輪子(component),首先我們要想到,第一次向后臺(tái)發(fā)起請求,我們只能獲取到第0個(gè)component的數(shù)據(jù),只有當(dāng)你滾動(dòng)輪子的時(shí)候才會(huì)獲取到省的Id發(fā)起請求來獲得該省的市的數(shù)據(jù),也就是第1個(gè)component的數(shù)據(jù),依此類推,滾動(dòng)第1個(gè)component發(fā)起請求來獲取第2個(gè)component的數(shù)據(jù),因此,pickView的監(jiān)聽輪子滾動(dòng)的代理起了重要作用
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component;
我們通過接口獲取第0個(gè)component的數(shù)據(jù),這邊是后臺(tái)規(guī)定的使用id=0,獲取到以后,默認(rèn)選中第0個(gè)component的第0個(gè)row并主動(dòng)調(diào)用觸發(fā)pick的輪子滾動(dòng)代理來聯(lián)動(dòng)第1個(gè)component【要在獲取數(shù)據(jù)成功后再執(zhí)行這部操作,因此放在數(shù)據(jù)請求成功的回調(diào)內(nèi)】,代碼為
[self pickerView:self.pickerView didSelectRow:0 inComponent:0 ];
在各輪子滾動(dòng)過程中,用一個(gè)中間值
_selectedRow0記錄下第0個(gè)component的選中行
_selectedRow1記錄下第1個(gè)component的選中行
_selectedRow2記錄下第2個(gè)component的選中行,
這里需要記住,滾動(dòng)某個(gè)輪子只能對(duì)它后面的輪子產(chǎn)生影響,所以當(dāng)滾動(dòng)第0個(gè)component的時(shí)候使_selectedRow1,_selectedRow2均置為0,這里注意,上面提到的
默認(rèn)選中第0個(gè)component的第0個(gè)row并主動(dòng)調(diào)用觸發(fā)pick的輪子滾動(dòng)代理來聯(lián)動(dòng)第1個(gè)component
要先將輪子上的數(shù)據(jù)渲染好,設(shè)置好默認(rèn)值才能主動(dòng)調(diào)用監(jiān)聽輪子滾動(dòng)的代理,否則會(huì)導(dǎo)致崩潰,另一個(gè)防崩潰的點(diǎn)如下圖
發(fā)現(xiàn)第三級(jí)沒數(shù)據(jù)的時(shí)候,如果你在代碼里沒加【安全措施】,那也會(huì)導(dǎo)致崩潰,要在請求到第三級(jí)的數(shù)據(jù)后做下判斷,如果個(gè)數(shù)為空,將該級(jí)對(duì)應(yīng)的數(shù)據(jù)源置為nil。(其它兩級(jí)的輪子最好也加判斷)
最后,由于這是個(gè)封裝的類,最終要得到選中的詳細(xì)信息,可通過代理或block傳值給controller。
又是你們最喜歡show code環(huán)節(jié):
.h文件
#import <UIKit/UIKit.h> //定制代理協(xié)議 @protocol ZLMAddressPickerViewDelegate <NSObject> - (void)addressPickerViewDidSelected:(NSString *)areaName;//點(diǎn)擊上方完成按鈕的代理傳回拼接好的選中地址 - (void)addressPickerViewDidClose;//點(diǎn)擊關(guān)閉代理 @end @interface ZLMAddressPickerView : UIView @property (weak, nonatomic) id<ZLMAddressPickerViewDelegate> delegate; @end
.m文件
#import "ZLMAddressPickerView.h" #import "AFHttpUtils.h" #import "AreaModel.h" @interface ZLMAddressPickerView () <UIPickerViewDataSource, UIPickerViewDelegate> @property (strong, nonatomic) UIPickerView *pickerView; @property (strong, nonatomic) AreaModel *provBridge; @property (strong, nonatomic) AreaModel *cityBridge; @property (strong, nonatomic) AreaModel *areaBridge; @property (copy, nonatomic) NSArray<Area *> * provDataArr;//省數(shù)組 @property (copy, nonatomic) NSArray<Area *> * cityDataArr;//市數(shù)組 @property (copy, nonatomic) NSArray<Area *> * areaDataArr;//區(qū)數(shù)組 @end @implementation ZLMAddressPickerView { NSInteger _selectRow0;//記錄第0個(gè)輪子的選擇行 NSInteger _selectRow1; NSInteger _selectRow2; NSString *_areaString;//最后要傳回的詳細(xì)地址拼接字符串 Area *_proModel;//記錄下選中省的數(shù)據(jù) Area *_cityModel; Area *_areaModel; } - (instancetype)initWithFrame:(CGRect)frame { self = [super initWithFrame:frame]; if (self) { [self setup]; } return self; } - (void)setup { _selectRow0 = 0; _selectRow1 = 0; _selectRow2 = 0; self.backgroundColor = [UIColor whiteColor]; UIToolbar *toolbar = [[UIToolbar alloc] initWithFrame:CGRectMake(0, 0, CGRectGetWidth(self.bounds), 44)]; toolbar.backgroundColor = [UIColor whiteColor]; [self addSubview:toolbar]; UIBarButtonItem *closeItem = [[UIBarButtonItem alloc] initWithTitle:@"關(guān)閉" style:UIBarButtonItemStylePlain target:self action:@selector(selectAddressClose)]; UIBarButtonItem *completeItem = [[UIBarButtonItem alloc] initWithTitle:@"完成" style:UIBarButtonItemStylePlain target:self action:@selector(selectAddressComplete)]; UIBarButtonItem *spaceItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:nil action:nil]; toolbar.items = @[closeItem, spaceItem, completeItem]; self.pickerView.frame = CGRectMake(0, 44, CGRectGetWidth(self.bounds), CGRectGetHeight(self.bounds) - 44); [self addSubview:self.pickerView]; [self downloadProv]; } #pragma mark - http methods /*省*/ - (void)downloadProv { NSMutableDictionary *dic = [NSMutableDictionary dictionaryWithDictionary: @{@"id":@(0)} ]; [AFHttpUtils sendPostTaskWithUrl:[NSString stringWithFormat:@"%@/app/member/area",BASE_DOMAIN_URL] paramenters:dic successHandle:^(NSURLSessionDataTask *task, id responseObject) { NSLog(@"PROV:%@",responseObject); self.provBridge = [AreaModel mj_objectWithKeyValues:responseObject]; if (self.provBridge.error_code==0) { self.provDataArr=self.provBridge.data; [self pickerView:self.pickerView didSelectRow:0 inComponent:0 ];//聯(lián)動(dòng)輪子1 必須得本輪有數(shù)據(jù)后才能觸發(fā)didselect [self.pickerView reloadAllComponents]; } } errorHandle:^(NSError *error) { }]; } /*市*/ - (void)downloadCityWithId:(NSInteger)provId { NSMutableDictionary *dic = [NSMutableDictionary dictionaryWithDictionary: @{@"id":@(provId)} ]; [AFHttpUtils sendPostTaskWithUrl:[NSString stringWithFormat:@"%@/app/member/area",BASE_DOMAIN_URL] paramenters:dic successHandle:^(NSURLSessionDataTask *task, id responseObject) { NSLog(@"CITY:%@",responseObject); self.cityBridge = [AreaModel mj_objectWithKeyValues:responseObject]; if (self.cityBridge.error_code==0) { self.cityDataArr=self.cityBridge.data; [self.pickerView reloadComponent:1]; [self.pickerView selectRow:0 inComponent:1 animated:YES];//默認(rèn)選擇row0 [self pickerView:self.pickerView didSelectRow:0 inComponent:1 ];//聯(lián)動(dòng)輪子2 必須得本輪有數(shù)據(jù)后才能觸發(fā)didselect _cityModel = self.cityDataArr[_selectRow1]; [self downloadAreaWithId:_cityModel.area_id]; } } errorHandle:^(NSError *error) { }]; } /*區(qū)*/ - (void)downloadAreaWithId:(NSInteger)cityId { NSMutableDictionary *dic = [NSMutableDictionary dictionaryWithDictionary: @{@"id":@(cityId)} ]; [AFHttpUtils sendPostTaskWithUrl:[NSString stringWithFormat:@"%@/app/member/area",BASE_DOMAIN_URL] paramenters:dic successHandle:^(NSURLSessionDataTask *task, id responseObject) { NSLog(@"AREA:%@",responseObject); self.areaBridge = [AreaModel mj_objectWithKeyValues:responseObject]; if (self.areaBridge.error_code==0&&self.areaBridge.data.count>0) { self.areaDataArr=self.areaBridge.data; }else{ self.areaDataArr=nil; } [self.pickerView reloadComponent:2]; [self.pickerView selectRow:0 inComponent:2 animated:YES]; [self pickerView:self.pickerView didSelectRow:0 inComponent:2 ]; } errorHandle:^(NSError *error) { }]; } #pragma mark - events response - (void)selectAddressComplete { [self.delegate addressPickerViewDidSelected:_areaString]; } - (void)selectAddressClose { [self.delegate addressPickerViewDidClose]; } #pragma mark - UIPickerViewDataSource //確定picker的輪子個(gè)數(shù) - (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView { return 3; } //確定picker的每個(gè)輪子的item數(shù) - (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component { if (component==0) { return self.provDataArr.count; }else if(component==1){ return self.cityDataArr.count; }else{ return self.areaDataArr.count; } } - (CGFloat)pickerView:(UIPickerView *)pickerView rowHeightForComponent:(NSInteger)component{ return 36; } //確定每個(gè)輪子的每一項(xiàng)顯示什么內(nèi)容 - (NSAttributedString *)pickerView:(UIPickerView *)pickerView attributedTitleForRow:(NSInteger)row forComponent:(NSInteger)component{ NSDictionary * attrDic = @{NSForegroundColorAttributeName:[UIColor blackColor], NSFontAttributeName:[UIFont systemFontOfSize:12]}; Area *area; if (component==0) { area = self.provDataArr[row]; }else if(component==1){ area = self.cityDataArr[row]; }else{ area = self.areaDataArr[row]; } NSAttributedString * attrString = [[NSAttributedString alloc] initWithString:area.name attributes:attrDic]; return attrString; } //監(jiān)聽輪子的移動(dòng) - (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component { if (component==0) { _selectRow0 = [pickerView selectedRowInComponent:0]; _selectRow1 = 0; _selectRow2 = 0; _proModel = self.provDataArr[_selectRow0]; [self downloadCityWithId:_proModel.area_id]; }else if(component==1){ _selectRow1 = [pickerView selectedRowInComponent:1]; _selectRow2 = 0; _cityModel = self.cityDataArr[_selectRow1]; [self downloadAreaWithId:_cityModel.area_id]; }else{ _selectRow2 = [pickerView selectedRowInComponent:2]; if (self.areaDataArr&&self.areaDataArr.count>0) { _areaModel = self.areaDataArr[_selectRow2]; }else{ _areaModel = nil; } } if(_areaModel==nil){ _areaString = [NSString stringWithFormat:@"%@ %@",_proModel.name,_cityModel.name]; }else{ _areaString = [NSString stringWithFormat:@"%@ %@ %@",_proModel.name,_cityModel.name,_areaModel.name]; } } #pragma mark - getters and setters - (UIPickerView *)pickerView { if (_pickerView == nil) { _pickerView = [[UIPickerView alloc] init]; _pickerView.delegate = self; _pickerView.dataSource = self; } return _pickerView; } @end
最后在controller中調(diào)用
(1)導(dǎo)入
#import "ZLMAddressPickerView.h"
(2)定義一個(gè)對(duì)象并遵守代理協(xié)議
@property (strong, nonatomic) ZLMAddressPickerView *addressPickerView;
(3)懶加載生成對(duì)象(個(gè)人習(xí)慣)
- (ZLMAddressPickerView *)addressPickerView { if (!_addressPickerView) { _addressPickerView = [[ZLMAddressPickerView alloc] initWithFrame:CGRectMake(0, SCREEN_HEIGHT-244-64, SCREEN_WIDTH, 244)]; _addressPickerView.delegate = self; } return _addressPickerView; }
(4)在點(diǎn)擊跳出三級(jí)聯(lián)動(dòng)選擇器的地方
[self.view addSubview:self.addressPickerView];
(5)別忘了實(shí)現(xiàn)代理
#pragma mark - ZLMAddressPickerViewDelegate - (void)addressPickerViewDidSelected:(NSString *)areaName { self.areaLabel.text = areaName;//將傳回的詳細(xì)地址字符串賦值 [self addressPickerViewDidClose]; } - (void)addressPickerViewDidClose { [self.addressPickerView removeFromSuperview]; }
上述內(nèi)容就是怎么在iOS中實(shí)現(xiàn)一個(gè)三級(jí)聯(lián)動(dòng)選擇器,你們學(xué)到知識(shí)或技能了嗎?如果還想學(xué)到更多技能或者豐富自己的知識(shí)儲(chǔ)備,歡迎關(guān)注億速云行業(yè)資訊頻道。
免責(zé)聲明:本站發(fā)布的內(nèi)容(圖片、視頻和文字)以原創(chuàng)、轉(zhuǎn)載和分享為主,文章觀點(diǎn)不代表本網(wǎng)站立場,如果涉及侵權(quán)請聯(lián)系站長郵箱:is@yisu.com進(jìn)行舉報(bào),并提供相關(guān)證據(jù),一經(jīng)查實(shí),將立刻刪除涉嫌侵權(quán)內(nèi)容。