UIPickerView的属性和常用方法 举例:显示省份和城市
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1 #import "ViewController.h" 2 3 @interface ViewController () 4 5 @property(strong, nonatomic) UIPickerView * pickerView; 6 @property(strong, nonatomic) UILabel * label; 7 @property(strong, nonatomic) UIButton * button; 8 @property (nonatomic, strong) NSDictionary *pickerData; //保存全部数据 9 @property (nonatomic, strong) NSArray *pickerProvincesData;//当前的省数据 10 @property (nonatomic, strong) NSArray *pickerCitiesData;//当前的省下面的市数据 11 12 @end 13 14 @implementation ViewController 15 16 - (void)viewDidLoad { 17 [super viewDidLoad]; 18 // Do any additional setup after loading the view, typically from a nib. 19 20 self.pickerView = [[UIPickerView alloc]initWithFrame:CGRectMake(0, 48, 320, 162)]; 21 self.pickerView.backgroundColor = [UIColor groupTableViewBackgroundColor]; 22 [self.view addSubview:self.pickerView]; 23 self.label = [[UILabel alloc]initWithFrame:CGRectMake(63, 285, 195, 33)]; 24 self.label.textAlignment = NSTextAlignmentCenter; 25 self.label.text = @"显示信息"; 26 self.label.backgroundColor = [UIColor groupTableViewBackgroundColor]; 27 [self.view addSubview:self.label]; 28 self.button = [[UIButton alloc]initWithFrame:CGRectMake(88, 413, 144, 44)]; 29 [self.button setTitle:@"显示在Label上" forState:UIControlStateNormal]; 30 self.button.backgroundColor = [UIColor brownColor]; 31 [self.button addTarget:self action:@selector(tapShow) forControlEvents:UIControlEventTouchUpInside]; 32 [self.view addSubview:self.button]; 33 34 NSString *plistPath = [[NSBundle mainBundle] pathForResource:@"PC" ofType:@"plist"]; 35 //获取属性列表文件中的全部数据 36 NSDictionary *dict = [[NSDictionary alloc] initWithContentsOfFile:plistPath]; 37 self.pickerData = dict; 38 39 //省份名数据 40 self.pickerProvincesData = [self.pickerData allKeys]; 41 42 //默认取出第一个省的所有市的数据 43 NSString *seletedProvince = [self.pickerProvincesData objectAtIndex:0]; 44 self.pickerCitiesData = [self.pickerData objectForKey:seletedProvince]; 45 46 self.pickerView.dataSource = self; 47 self.pickerView.delegate = self; 48 49 50 } 51 52 - (void)tapShow 53 { 54 NSInteger row1 = [self.pickerView selectedRowInComponent:0]; 55 NSInteger row2 = [self.pickerView selectedRowInComponent:1]; 56 //NSLog(@"row1 = %lu",row1); 57 //NSLog(@"row2 = %lu",row2); 58 NSString *selected1 = [self.pickerProvincesData objectAtIndex:row1]; 59 NSString *selected2 = [self.pickerCitiesData objectAtIndex:row2]; 60 61 NSString *title = [[NSString alloc] initWithFormat:@"%@,%@", 62 selected1,selected2]; 63 64 self.label.text = title; 65 66 } 67 68 #pragma mark 实现协议UIPickerViewDataSource方法 69 - (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView { 70 return 2; 71 } 72 //初始化时component先为0,后为1,返回省份个数和和市的个数,以确定省份的行数和市的临时初始化行数。此后选择省的时候component为1,返回市的个数 73 - (NSInteger)pickerView:(UIPickerView *)pickerView 74 numberOfRowsInComponent:(NSInteger)component { 75 if (component == 0) 76 {//省份个数 77 return [self.pickerProvincesData count]; 78 } else 79 {//市的个数 80 return [self.pickerCitiesData count]; 81 } 82 83 } 84 85 #pragma mark 实现协议UIPickerViewDelegate方法 86 //选择省份的时候component先为0,后为1。然后选择市的时候返回市所在的row号。将其省和市显示在pickerview的显示条上 87 -(NSString *)pickerView:(UIPickerView *)pickerView 88 titleForRow:(NSInteger)row forComponent:(NSInteger)component { 89 //NSLog(@"row2 = %lu",row); 90 //NSLog(@"component2 = %lu",component); 91 if (component == 0) 92 {//选择省份名 93 return [self.pickerProvincesData objectAtIndex:row]; 94 } else 95 {//选择市名 96 return [self.pickerCitiesData objectAtIndex:row]; 97 } 98 } 99 //只有选择省份的时候component为0,返回省所在的row号,然后根据省份取出省所有的市。选择市的时候component为1。(作用为重新加载数据到pickerview上) 100 - (void)pickerView:(UIPickerView *)pickerView 101 didSelectRow:(NSInteger)row inComponent:(NSInteger)component { 102 //NSLog(@"row3 = %lu",row); 103 //NSLog(@"component3 = %lu",component); 104 if (component == 0) 105 { 106 NSString *seletedProvince = [self.pickerProvincesData objectAtIndex:row]; 107 NSArray *array = [self.pickerData objectForKey:seletedProvince]; 108 //NSLog(@"array = %@",array); 109 self.pickerCitiesData = array;//将所选省的所有市存入pickerCitiesData 110 [self.pickerView reloadComponent:1]; 111 } 112 } 113 - (void)didReceiveMemoryWarning { 114 [super didReceiveMemoryWarning]; 115 // Dispose of any resources that can be recreated. 116 } 117 118 @end
1、常用属性
//显示选中框
showsSelectionIndicator
2、常用方法
//返回rows的所有行号行号
- (NSInteger)numberOfRowsInComponent:(NSInteger)component;
//重新加载所有的元素
- (void)reloadAllComponents;
//通过赋值加载所选择的数据
- (void)reloadComponent:(NSInteger)component;
//协议UIPickerViewDataSource方法
//确定轮子的列数
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView {
return 2;
}
//初始化时component先为0,后为1,返回省份个数和和市的个数,以确定省份的行数和市的临时初始化行数。此后选择省的时候component为1,返回市的个数
- (NSInteger)pickerView:(UIPickerView *)pickerView
numberOfRowsInComponent:(NSInteger)component {
if (component == 0)
{//省份个数
return [self.pickerProvincesData count];
} else
{//市的个数
return [self.pickerCitiesData count];
}
}
//协议UIPickerViewDelegate方法
//选择省份的时候component先为0,后为1。然后选择市的时候返回市所在的row号。将其省和市显示在pickerview的显示条上
-(NSString *)pickerView:(UIPickerView *)pickerView
titleForRow:(NSInteger)row forComponent:(NSInteger)component {
//NSLog(@"row2 = %lu",row);
//NSLog(@"component2 = %lu",component);
if (component == 0)
{//选择省份名
return [self.pickerProvincesData objectAtIndex:row];
} else
{//选择市名
return [self.pickerCitiesData objectAtIndex:row];
}
}
//只有选择省份的时候component为0,返回省所在的row号,然后根据省份取出省所有的市。选择市的时候component为1。(作用为重新加载数据到pickerview上)
- (void)pickerView:(UIPickerView *)pickerView
didSelectRow:(NSInteger)row inComponent:(NSInteger)component {
//NSLog(@"row3 = %lu",row);
//NSLog(@"component3 = %lu",component);
if (component == 0)
{
NSString *seletedProvince = [self.pickerProvincesData objectAtIndex:row];
NSArray *array = [self.pickerData objectForKey:seletedProvince];
//NSLog(@"array = %@",array);
self.pickerCitiesData = array;//将所选省的所有市存入pickerCitiesData
[self.pickerView reloadComponent:1];
}
}