一、简介
该文主要实现的是省市区的选择，可在个人修改地址的地方使用。
二、需要的东西
制作这个首先需要一个area.plist文件，该文件中保存这所有的关于省市区的信息，下载地址：http://pan.baidu.com/s/1qWFPf8g。
三、制作原理
通过一个UIPickerView来显示，将UIPickerView分成三部分，省、市、区。进而加载数据。
四、实现效果
图片展示：
五、具体实现步骤：
1、首先，新建一个Single View APplication，然后在Storyboard中添加一个UIpicker View
，
2、实现UIPicker View的代理方法 --这里的数据是暂时的，还没添加数据
#pragma mark - UIPickerViewDelegate /** *返回每一列的数据个数 */ -(NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component { if(component==1) { return 2; }else if (component==2) { return 3; }else { return 4; } } /** *返回pickerView分几列，因为是省市区选择，所以分3列 */ -(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView { return 3; } /** *触发的事件 */ -(void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component { NSLog(@"ss"); } /** *通过自定义view去显示pickerView中的内容,这样做的好处是可以自定义的调整pickerView中显示内容的格式 */ -(UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view { UILabel *myView = nil; myView = [[UILabel alloc] initWithFrame:CGRectMake(0.0, 0.0, 100, 30)]; myView.textAlignment = NSTextAlignmentCenter; myView.font = [UIFont systemFontOfSize:15]; //用label来设置字体大小 if (component==0) { myView.text = @"1"; }else if (component==1) { myView.text = @"2"; }else { myView.text = @"3"; } return myView; }
3、接下来就是把刚才下载的那个area.plist文件中的数据加入到picker View中
①、首先定义三个NSArray。
NSArray *provinceArr,*cityArr,*areaArr;
②、先设置provinceArr.cityArr,areaArr.
provinceArr = [[NSMutableArray alloc] initWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"area.plist" ofType:nil]]; cityArr = [[provinceArr objectAtIndex:0] objectForKey:@"cities"]; areaArr = [[cityArr objectAtIndex:0] objectForKey:@"areas"];
默认的province列先显示的第一列，此时刚好让city显示第一列的city,让area显示第一个city的area。
注：（此处这样设置是因为这个area.plist文件的结构的原因，你可以自己看一下这个plist文件）。
4、此时数据便有了，但是当滚动第一列时，第二列和第三列都没有变化，其实本质上就是在设置pickerView内容的代理方法中设置内容改变。重头戏来了。--修改上面的这个代理方法。
-(void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component { if (component==0) { //当是省的时候 cityArr = [[provinceArr objectAtIndex:row] objectForKey:@"cities"]; [pickerView selectRow:0 inComponent:1 animated:NO]; [self.areaPicker reloadComponent:1]; if ([cityArr count]!=0) { areaArr = [[cityArr objectAtIndex:0] objectForKey:@"areas"]; [pickerView selectRow:0 inComponent:2 animated:NO]; [self.areaPicker reloadComponent:2]; } } else if (component==1) { areaArr = [[cityArr objectAtIndex:row] objectForKey:@"areas"]; [pickerView selectRow:0 inComponent:2 animated:NO]; [self.areaPicker reloadComponent:2]; } } 注：不要忘了重新设置每一列的数据个数 if (component==0) { return [provinceArr count]; }else if(component==1) { return [cityArr count]; }else { return [areaArr count]; }
5、附加：
获取三列的内容 province= [[provinceArr objectAtIndex:[self.areaPicker selectedRowInComponent:0]] objectForKey:@"state"]; //获取province city= [[cityArr objectAtIndex:[self.areaPicker selectedRowInComponent:1]] objectForKey:@"city"]; if ([areaArr count]!=0) { area = [areaArr objectAtIndex:[self.areaPicker selectedRowInComponent:2]]; }
6、完成，附上源码。（故事版上的设置大家自己设置就行了）
// // ViewController.m // ProvinceCityDownTownChoose // // Created by xiaoguizi on 15/2/9. // Copyright (c) 2015年 xiaoguizi. All rights reserved. // ------.m文件------ #import "ViewController.h" @interface ViewController () { NSArray *provinceArr,*cityArr,*areaArr; } @end @implementation ViewController - (void)viewDidLoad { [super viewDidLoad]; provinceArr = [[NSMutableArray alloc] initWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"area.plist" ofType:nil]]; cityArr = [[provinceArr objectAtIndex:0] objectForKey:@"cities"]; areaArr = [[cityArr objectAtIndex:0] objectForKey:@"areas"]; } #pragma mark - UIPickerViewDelegate /** *返回每一列的数据个数 */ -(NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component { if (component==0) { return [provinceArr count]; }else if(component==1) { return [cityArr count]; }else { return [areaArr count]; } } /** *返回pickerView分几列，因为是省市区选择，所以分3列 */ -(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView { return 3; } /** *触发的事件 */ -(void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component { if (component==0) { cityArr = [[provinceArr objectAtIndex:row] objectForKey:@"cities"]; [pickerView selectRow:0 inComponent:1 animated:NO]; [self.areaPicker reloadComponent:1]; if ([cityArr count]!=0) { areaArr = [[cityArr objectAtIndex:0] objectForKey:@"areas"]; [pickerView selectRow:0 inComponent:2 animated:NO]; [self.areaPicker reloadComponent:2]; } } else if (component==1) { areaArr = [[cityArr objectAtIndex:row] objectForKey:@"areas"]; [pickerView selectRow:0 inComponent:2 animated:NO]; [self.areaPicker reloadComponent:2]; } } /** *通过自定义view去显示pickerView中的内容,这样做的好处是可以自定义的调整pickerView中显示内容的格式 */ -(UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view { UILabel *myView = nil; myView = [[UILabel alloc] initWithFrame:CGRectMake(0.0, 0.0, 100, 30)]; myView.textAlignment = NSTextAlignmentCenter; myView.font = [UIFont systemFontOfSize:15]; //用label来设置字体大小 if (component==0) { myView.text =[[provinceArr objectAtIndex:row] objectForKey:@"state"]; }else if (component==1) { myView.text =[[cityArr objectAtIndex:row] objectForKey:@"city"]; }else { myView.text =[areaArr objectAtIndex:row]; } return myView; } @end ------.h文件------ // // ViewController.h // ProvinceCityDownTownChoose // // Created by xiaoguizi on 15/2/9. // Copyright (c) 2015年 xiaoguizi. All rights reserved. // #import <UIKit/UIKit.h> @interface ViewController : UIViewController<UIPickerViewDataSource,UIPickerViewDelegate> @property (weak, nonatomic) IBOutlet UIPickerView *areaPicker; @end