用UIPicker做一个类似省市联动选择的例子

用UIPicker做一个类似省市联动选择的例子

ViewController.h:
#import <UIKit/UIKit.h>
@interface ForthViewController :UIViewController<UIPickerViewDataSource,UIPickerViewDelegate>
@property (retain,nonatomic) IBOutlet UIPickerView *picker;
@property(nonatomic,retain)NSDictionary *dictionary;
@property(nonatomic,retain)NSArray *states;  //省
@property(nonatomic,retain)NSArray *zips;//市
@end
 
ViewController.m: 

#import"ForthViewController.h"
#define STATE_COMPONENT0
#define ZIP_COMPONENT  1
@interfaceForthViewController ()

@end

@implementation

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle
{
self = [superinitWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
       // Custom initialization
    }
     return self;
}

- (void)viewDidLoad
{
    [superviewDidLoad];
     NSBundle *bundle = [NSBundle mainBundle];//目录，地址
     NSURL * url = [bundle URLForResource:@"statedictionary"withExtension:@"plist"];
     NSString *path = [bundle pathForResource:@"statedictionary"ofType:@"plist"];
NSLog(@"%@",url);
NSLog(@"%@",path);
     NSDictionary *dic = [NSDictionary  dictionaryWithContentsOfFile:path];
self.dictionary
     NSLog(@"%@",self.dictionary);
NSArray *arr = [self.dictionaryallKeys];
self.states
self.dictionaryobjectForKey:self.states[0]];
self.zips
}

- (void)didReceiveMemoryWarning
{
    [superdidReceiveMemoryWarning];
    
}
//一个picker有几个compont
-(NSInteger)numberOfComponentsInPickerView:(UIPickerView
{
return2;
}
//每个组件有几行数据
-(NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
{
     //创建数据
if(component ==STATE_COMPONENT)
    {
 return [self.states  count];   //动态获取数字
    }
else
    {
 return [self.zips  count];
    }
}
//每行显示的内容
-(NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component
{
if (component ==STATE_COMPONENT) {
 return [self.states  objectAtIndex:row];
    }
else
    {
 return [self.zips  objectAtIndex:row];
    }
}
//选择一行就触发的事件
-(void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
{
if (component ==STATE_COMPONENT) {
 NSString *str = [self.statesobjectAtIndex:row];
 NSArray *arr = [self.dictionaryvalueForKey:self.states[row]];
 self.zips
       //因为component = ZIP_COMPONENT的数据发生改变，所以要重新导入
 reloadComponent:ZIP_COMPONENT];
       //防止越界，row超过现在的总行数
        [pickerViewselectRow:0inComponent:ZIP_COMPONENTanimated:YES];
    }
}

- (void)dealloc {
_pickerrelease];
    [_dictionaryrelease];
_statesrelease];
_zipsrelease];
superdealloc];
}
@end