IOS UIPickView+sqlite 选择中国所有城市案例
来源：程序员人生 发布时间：2014-09-06 23:36:14 阅读次数：3647次
1.案例简介
通过读取文件，将中国所有城市写入sqlite数据库中，现通过UIPickView实现中国所有城市的选择，效果图如下所示
2.城市对象模型
中国所有城市数据请看http://blog.csdn.net/whzhaochao/article/details/37969145，城市模型对象如下
//
// CityModel.h
// readData
//
// Created by 赵超 on 14-8-28.
// Copyright (c) 2014年 赵超. All rights reserved.
//
#import <Foundation/Foundation.h>
@interface CityModel : NSObject
@property (nonatomic,copy) NSString *pid; //父级城市ID
@property (nonatomic,copy) NSString *cityName; //城市名
@property (nonatomic,copy) NSString *ids; //城市ID
@end
3.城市数据库操作对象
sqlite封操作BseDB类请看http://blog.csdn.net/whzhaochao/article/details/38865535，然后封装城市对象的数据库操作对象CityDB
CityDB.h文件
//
// CityDB.h
// readData
//
// Created by 赵超 on 14-8-28.
// Copyright (c) 2014年 赵超. All rights reserved.
//
#import "BaseDB.h"
#import "CityModel.h"
@interface CityDB : BaseDB
/**
*CityDB单例
*/
+(id)ShareDB;
/**
* 创建数据库
* dbName:数据库名称
*/
-(void)creatTableWithDataBaseName:(NSString*) dbName;
/**
* 增加一个城市
* city:城市
* dbName:数据库名称
*/
-(BOOL)addCity:(CityModel*)city dbName:(NSString*)dbName;
/**
* 选择所有的城市
* dbName:数据库名称
*/
-(id)selectAllCity:(NSString*)dbName;
/**
* 选择所有的省份
* dbName:数据库名称
*/
-(id)selectAllProvince:(NSString *)dbName;
/**
* 删除所有城市
* dbName:数据库名称
*/
-(BOOL)deleteAllCity:(NSString*)dbName;
/**
* 通过上一级省份选择下级市
* city:上一级城市
* dbName:数据库名称
*/
-(id)selectCityByProvince:(CityModel*)provice dbName:(NSString*)dbName;
@end
CityDB.m文件实现
//
// CityDB.m
// readData
//
// Created by 赵超 on 14-8-28.
// Copyright (c) 2014年 赵超. All rights reserved.
//
#import "CityDB.h"
@implementation CityDB
static CityDB *citydb;
+(id)ShareDB{
if (citydb==nil) {
citydb=[[CityDB alloc] init];
}
return citydb;
}
-(void)creatTableWithDataBaseName:(NSString *)dbName{
NSString *sql=@"create table china (ids text primary key,cityName text,pid text )";
[self createTable:sql dataBaseName:dbName];
}
-(BOOL)addCity:(CityModel *)city dbName:(NSString *)dbName{
NSString *sql=@"insert into china values (?,?,?)";
NSArray *params=@[city.ids,city.cityName,city.pid];
return [self execSql:sql parmas:params dataBaseName:dbName];
}
-(id)selectAllCity:(NSString *)dbName{
NSString *sql=@"select ids,cityName,pid from china";
return [self selectCity:sql parmas:nil dbName:dbName];
}
-(id)selectCity:(NSString*)sql parmas:(NSArray*)params dbName:(NSString*)dbName{
NSArray *result= [self selectSql:sql parmas:params dataBaseName:dbName];
NSMutableArray *citys=[NSMutableArray array];
for (NSDictionary *dic in result) {
CityModel *city=[[CityModel alloc]init];
city.ids=[dic objectForKey:@"ids"];
city.cityName=[dic objectForKey:@"cityName"];
city.pid=[dic objectForKey:@"pid"];
[citys addObject:city];
}
return citys;
}
-(id)selectAllProvince:(NSString *)dbName{
NSString *sql=@"select ids,cityName,pid from china where pid=?";
NSArray *parmas=@[@"0"];
return [self selectCity:sql parmas:parmas dbName:dbName];
}
-(id)selectCityByProvince:(CityModel *)provice dbName:(NSString *)dbName{
NSString *sql=@"select * from china where pid=?";
NSArray *params=@[provice.ids];
return [self selectCity:sql parmas:params dbName:dbName];
}
-(BOOL)deleteAllCity:(NSString *)dbName{
NSString *sql=@"delete from china";
return [self execSql:sql parmas:nil dataBaseName:dbName];
}
@end
4.城市数据处理
中国城市数据放在china.txt中，需要处理后写入数据库中，读取文件装数据写入数据库代码如下
//调用CitDB对象向数据库中增加一个城市
-(void)addCity:(CityModel* )city{
[[CityDB ShareDB] addCity:city dbName:@"China.sqlite"];
}
//处理china.txt城市数据，将其写入数据库中
-(void)readData{
NSString *path=[[NSBundle mainBundle] pathForResource:@"china" ofType:@"txt"];
NSLog(@"%@",path);
char pid[30],name[30],ids[30];
FILE *f=fopen([path UTF8String], "r");
int i=0;
while (!feof(f)) {
CityModel *city=[[CityModel alloc] init];
fscanf(f, " %s %s %s ",ids,name,pid);
NSString *pids=[NSString stringWithUTF8String:pid];
NSString *names=[NSString stringWithUTF8String:name];
NSString *idss=[NSString stringWithUTF8String:ids];
city.ids=idss;
city.pid=pids;
city.cityName=names;
//向数据库插入一个城市
[self addCity:city];
NSLog(@"%@ %@ %@ %d",pids,names,idss,++i);
}
}
5.UIPickView显示数据
MainViewControoler用户数据的显示，其.h文件内容如下
@interface MainViewController : UIViewController<UIPickerViewDataSource,UIPickerViewDelegate>{
CityModel *privceModel; //选择的省
CityModel *cityModel; //选择的市
CityModel *subCityModel; //选择的地级市
CityModel *areaModel; //选择的区
UILabel *selectCity; //显示选择的结果
}
@property (nonatomic,retain) NSArray *privices; //所有省份
@property (nonatomic,retain) NSArray *citys; //省下对应的市
@property (nonatomic,retain) NSArray *subCitys; //市下对应的地级市
@property (nonatomic,retain) NSArray *area; //区
@end
在MainViewController的viewDidLoad中添加UIPickView并初始化数据
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
self.view.backgroundColor=[UIColor grayColor];
UIPickerView *pickView=[[UIPickerView alloc] initWithFrame:CGRectMake(0, 100, 0, 0)];
pickView.dataSource=self;
pickView.delegate=self;
pickView.showsSelectionIndicator=YES;
pickView.backgroundColor=[UIColor whiteColor];
[self.view addSubview:pickView];
//初始化数据
self.privices=[[CityDB ShareDB] selectAllProvince:dataBaseName];
CityModel *city=[self.privices objectAtIndex:0];
self.citys=[[CityDB ShareDB] selectCityByProvince:city dbName:dataBaseName];
city=[self.citys objectAtIndex:0];
self.subCitys=[[CityDB ShareDB] selectCityByProvince:city dbName:dataBaseName];
city=[self.citys objectAtIndex:0];
self.area=[[CityDB ShareDB] selectCityByProvince:city dbName:dataBaseName];
selectCity=[[UILabel alloc] initWithFrame:CGRectMake(0, 40, 320, 30)];
}
实现UIPickView的列数和行数代理函数，列数只有4列，第一列的行数是中国所有的省数所以中人返回self.privices.count就可以了，但是第二列必需知道第一列选中哪个省份后，再通过这个省份从数据库库查出下面的市才知道要显示的行数，第3列是基于第2列选中的行数，第4列是基于第3列选中的列数，实现代码如下：
//UIPcikView总共4列
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView{
return 4;
}
//为每列加载行数
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component{
if (component==0) {
return self.privices.count;
}else
if (component==1) {
//获取第一列选中的省份列表
NSInteger privoceIndex=[pickerView selectedRowInComponent:0];
CityModel *privoice=[self.privices objectAtIndex:privoceIndex];
//从数据库中查询，省份下面的市
self.citys=[[CityDB ShareDB] selectCityByProvince:privoice dbName:dataBaseName];
//返回市的个数
return self.citys.count;
}else
if (component==2) {
NSInteger cityIndex=[pickerView selectedRowInComponent:1];
if (self.citys.count==0) {
return 0;
}
CityModel *subCitys=[self.citys objectAtIndex:cityIndex];
self.subCitys=[[CityDB ShareDB] selectCityByProvince:subCitys dbName:dataBaseName];
return self.subCitys.count;
}else
if (component==3) {
NSInteger subCityIndex=[pickerView selectedRowInComponent:2];
if (self.subCitys.count==0) {
return 0;
}
CityModel *ares=[self.subCitys objectAtIndex:subCityIndex];
self.area=[[CityDB ShareDB] selectCityByProvince:ares dbName:dataBaseName];
return self.area.count;
}else{
return 0;
}
}
为UIPickView加载每行每列的数据，获取数据时要注意有判断是否为空
//获取每列每行的名称
-(NSString*)getCityName:(NSInteger)row componet:(NSInteger) component{
if (component==0) {
CityModel *city=[self.privices objectAtIndex:row];
return city.cityName;
}else if (component==1) {
CityModel *city=[self.citys objectAtIndex:row];
return city.cityName;
}else if (component==2) {
if (self.subCitys==nil) {
return @"";
}else{
CityModel *city=[self.subCitys objectAtIndex:row];
return city.cityName;
}
}
else if (component==3) {
if (self.area==nil) {
return @"";
}else{
CityModel *city=[self.area objectAtIndex:row];
return city.cityName;
}
}
return @"";
}
-(UIView*) pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view{
UILabel *lable=[[UILabel alloc] initWithFrame:CGRectMake(0, 0, 60, 30)];
//获取名称
lable.text=[self getCityName:row componet:component];
lable.font=[UIFont systemFontOfSize:14];
return lable;
}
最后实现UIPickView的选择响应事件刷新Pickview，并显示选择的结果
//获取每列每行的名称
-(NSString*)getCityName:(NSInteger)row componet:(NSInteger) component{
if (component==0) {
CityModel *city=[self.privices objectAtIndex:row];
return city.cityName;
}else if (component==1) {
CityModel *city=[self.citys objectAtIndex:row];
return city.cityName;
}else if (component==2) {
if (self.subCitys==nil) {
return @"";
}else{
CityModel *city=[self.subCitys objectAtIndex:row];
return city.cityName;
}
}
else if (component==3) {
if (self.area==nil) {
return @"";
}else{
CityModel *city=[self.area objectAtIndex:row];
return city.cityName;
}
}
return @"";
}
-(UIView*) pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view{
UILabel *lable=[[UILabel alloc] initWithFrame:CGRectMake(0, 0, 60, 30)];
//获取名称
lable.text=[self getCityName:row componet:component];
lable.font=[UIFont systemFontOfSize:14];
return lable;
}
项目完整工程https://github.com/whzhaochao/IOSChinaCity
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