效果图:
#import "RootViewController.h"
@interface RootViewController ()
@end
@implementation RootViewController
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{ self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {// Custom initialization }
return self;
}
- (void)viewDidLoad
{[super viewDidLoad];
// Do any additional setup after loading the view.
// 初始化身份数据
NSMutableArray *tempArray1 = [NSMutableArray arrayWithObjects:@"北京", @"河北", @"天津", nil];
self.citysArray = tempArray1;
// 初始化城市数据 @"朝阳区", @"海淀区", @"西城区", @"东城区", "昌平区", nil
NSMutableArray *tempArray2 = [NSMutableArray arrayWithObjects:@"朝阳区", @"海淀区", @"西城区", @"东城区", @"昌平区", nil];
self.districtesArray = tempArray2;
// 初始化UIPickerView
UIPickerView *onePickerView = [[UIPickerView alloc] initWithFrame:CGRectMake(0, self.view.frame.size.height - 216, 320, 216)];
// 设置委托对象
onePickerView.delegate = self;
onePickerView.showsSelectionIndicator = YES; // 设置选中的一行高亮显示
// 设置数据源对象
onePickerView.dataSource = self;
self.pickerView = onePickerView;
[onePickerView release], onePickerView = nil;
[self.view addSubview:_pickerView];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
#pragma mark - 重写---滚动滚轮调用的方法
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component {
if (component == 0) {
switch (row) {
case 0:
self.districtesArray = [NSMutableArray arrayWithObjects:@"朝阳区", @"海淀区", @"西城区", @"东城区", @"昌平区", nil];
break;
case 1:
self.districtesArray = [NSMutableArray arrayWithObjects:@"保定", @"沧州", @"邢台", @"唐山", nil];
break;
case 2:
self.districtesArray = [NSMutableArray arrayWithObjects:@"红桥区", @"北辰区", @"西青区", @"武清区", @"呵呵", nil];
break;
default:
break;
}
// 修改完数据之后重新加载数据
[pickerView reloadComponent:1];
// 设置默认选中的为第二个滚轮的第一个选项
[pickerView selectRow:0 inComponent:1 animated:YES];
} }
#pragma mark - 重写---协议中的方法
#pragma mark 设置总共有几个滚轮 返回值是几既有机房
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView {
return 2;
}
#pragma mark 这种相同的数据源返回相同的数据源
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component {
if (component == 0) { // 判断是左面第一个滚轮
return self.citysArray.count;
} else {
return self.districtesArray.count;
} }
#pragma mark - 重写---获取数据源显示在UIPickerView上
- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component {
if (component == 0) {
return [self.citysArray objectAtIndex:row];
} else {
return [self.districtesArray objectAtIndex:row]; }
}
#pragma mark - 重写---dealloc方法
- (void)dealloc {
[_pickerView release], _pickerView = nil;
[super dealloc];
}
@end