【移动应用开发技术】怎么在iOS中实现一个三级联动选择器

【移动应用开发技术】怎么在iOS中实现一个三级联动选择器

本篇文章为大家展示了怎么在iOS中实现一个三级联动选择器，内容简明扼要并且容易理解，绝对能使你眼前一亮，通过这篇文章的详细介绍希望你能有所收获。1）怎么设置默认值，关键代码[self.pickerView

selectRow:xxx

inComponent:xxx

animated:YES];2）怎么让三级之间联动,关键代码[self

pickerView:self.pickerView

didSelectRow:0

inComponent:0

];//联动轮子1

必须得本轮有数据后触发否则crash先看下效果图关于设置默认值，三级联动，用UIPickView的话就是有3个轮子（component），首先我们要想到，第一次向后台发起请求，我们只能获取到第0个component的数据，只有当你滚动轮子的时候才会获取到省的Id发起请求来获得该省的市的数据，也就是第1个component的数据，依此类推，滚动第1个component发起请求来获取第2个component的数据，因此，pickView的监听轮子滚动的代理起了重要作用-

(void)pickerView:(UIPickerView

*)pickerView

didSelectRow:(NSInteger)row

inComponent:(NSInteger)component；我们通过接口获取第0个component的数据，这边是后台规定的使用id=0，获取到以后，默认选中第0个component的第0个row并主动调用触发pick的轮子滚动代理来联动第1个component【要在获取数据成功后再执行这部操作,因此放在数据请求成功的回调内】，代码为

[self

pickerView:self.pickerView

didSelectRow:0

inComponent:0

];在各轮子滚动过程中,用一个中间值_selectedRow0记录下第0个component的选中行_selectedRow1记录下第1个component的选中行_selectedRow2记录下第2个component的选中行，这里需要记住，滚动某个轮子只能对它后面的轮子产生影响，所以当滚动第0个component的时候使_selectedRow1，_selectedRow2均置为0，这里注意，上面提到的默认选中第0个component的第0个row并主动调用触发pick的轮子滚动代理来联动第1个component要先将轮子上的数据渲染好，设置好默认值才能主动调用监听轮子滚动的代理，否则会导致崩溃，另一个防崩溃的点如下图发现第三级没数据的时候，如果你在代码里没加【安全措施】，那也会导致崩溃，要在请求到第三级的数据后做下判断，如果个数为空，将该级对应的数据源置为nil。（其它两级的轮子最好也加判断）最后，由于这是个封装的类，最终要得到选中的详细信息，可通过代理或block传值给controller。又是你们最喜欢showcode环节：.h文件#import

<UIKit/UIKit.h>

//定制代理协议

@protocol

ZLMAddressPickerViewDelegate

<NSObject>

-

(void)addressPickerViewDidSelected:(NSString

*)areaName;//点击上方完成按钮的代理传回拼接好的选中地址

-

(void)addressPickerViewDidClose;//点击关闭代理

@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;//省数组

@property

(copy,

nonatomic)

NSArray<Area

*>

*

cityDataArr;//市数组

@property

(copy,

nonatomic)

NSArray<Area

*>

*

areaDataArr;//区数组

@end

@implementation

ZLMAddressPickerView

{

NSInteger

_selectRow0;//记录第0个轮子的选择行

NSInteger

_selectRow1;

NSInteger

_selectRow2;

NSString

*_areaString;//最后要传回的详细地址拼接字符串

Area

*_proModel;//记录下选中省的数据

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:@"关闭"

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);

vBridge

=

[AreaModel

mj_objectWithKeyValues:responseObject];

if

(vBridge.error_code==0)

{

vDataArr=vBridge.data;

[self

pickerView:self.pickerView

didSelectRow:0

inComponent:0

];//联动轮子1

必须得本轮有数据后才能触发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];//默认选择row0

[self

pickerView:self.pickerView

didSelectRow:0

inComponent:1

];//联动轮子2

必须得本轮有数据后才能触发didselect

_cityModel

=

self.cityDataArr[_selectRow1];

[self

downloadAreaWithId:_cityModel.area_id];

}

}

errorHandle:^(NSError

*error)

{

}];

}

/*区*/

-

(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

//确定picker的轮子个数

-

(NSInteger)numberOfComponentsInPickerView:(UIPickerView

*)pickerView

{

return

3;

}

//确定picker的每个轮子的item数

-

(NSInteger)pickerView:(UIPickerView

*)pickerView

numberOfRowsInComponent:(NSInteger)component

{

if

(component==0)

{

return

vDataArr.count;

}else

if(component==1){

return

self.cityDataArr.count;

}else{

return

self.areaDataArr.count;

}

}

-

(CGFloat)pickerView:(UIPickerView

*)pickerView

rowHeightForComponent:(NSInteger)component{

return

36;

}

//确定每个轮子的每一项显示什么内容

-

(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

=

vDataArr[row];

}else

if(component==1){

area

=

self.cityDataArr[row];

}else{

area

=

self.areaDataArr[row];

}

NSAttributedString

*

attrString

=

[[NSAttributedString

alloc]

initWithString:

attributes:attrDic];

return

attrString;

}

//监听轮子的移动

-

(void)pickerView:(UIPickerView

*)pickerView

didSelectRow:(NSInteger)row

inComponent:(NSInteger)component

{

if

(component==0)

{

_selectRow0

=

[pickerView

selectedRowInComponent:0];

_selectRow1

=

0;

_selectRow2

=

0;

_proModel

=

vDataArr[_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:@"%@

%@",_proM,_cityM];

}else{

_areaString

=

[NSString

stringWithFormat:@"%@

%@

%@",_proM,_cityM,_areaM];

}

}

#pragma

mark

-

getters

and

setters

-

(UIPickerView

*)pickerView

{

if