选择器控件UIPickerView:

功能：它能够创建一个类似于密码锁式的单列或多列的选择菜单，用户可以通过它设置的代理来选择需要菜单中的任意的数据。例如创建日历、字体表(类型、大小、颜色)、图库等.

 

它是UIView视图的子类，而且遵从UIPickerViewDelegate协议和UIPickerViewDataSource协议。因此，选择器需要设置代理去进行操作;

设置视图控制器self为数据源代理和数据操作代理,即

@property(strong,nonatomic)UIPickerView *pickerView;

self.pickerView.dataSource = self;

self.pickerView.delegate  = self;

 

一、具体类信息：

 @protocol UIPickerViewDataSource, UIPickerViewDelegate;

 @interface UIPickerView : UIView <NSCoding>

 @property(nonatomic,assign) id<UIPickerViewDataSource> dataSource; // default is nil,设置代理

 @property(nonatomic,assign) id<UIPickerViewDelegate>   delegate;  // default is nil，设置代理

 @property(nonatomic)  BOOL showsSelectionIndicator;    // default is NO

 @property(nonatomic,readonly) NSInteger numberOfComponents; //列数

 

二、协议UIPickerViewDataSource

@protocol UIPickerViewDataSource<NSObject>

@required //必须要实现的方法

// 返回的列显示的数量。

- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView;

//返回行数在每个组件(每一列)

- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component;

@end

 

三、协议UIPickerViewDelegate

@protocol UIPickerViewDelegate<NSObject>

@optional //可以选择执行的方法

//每一列组件的列宽度

- (CGFloat)pickerView:(UIPickerView *)pickerView widthForComponent:(NSInteger)component;

//每一列组件的行高度

- (CGFloat)pickerView:(UIPickerView *)pickerView rowHeightForComponent:(NSInteger)component;

// 返回每一列组件的每一行的标题内容

- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component;

// 返回每一列组件的每一行的标题内容的属性

- (NSAttributedString *)pickerView:(UIPickerView *)pickerView attributedTitleForRow:(NSInteger)row forComponent:(NSInteger)component;

// 返回每一列组件的每一行的视图显示

- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view;

//执行选择某列某行的操作

- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component;

@end

 

   

演示一：制作简单的万年历,一开始就显示当前日期

源码如下：

1 #import 
      
       2 3 @interface ViewController : UIViewController
       
        4 @property(nonatomic,strong)NSArray *years;5 @property(nonatomic,strong)NSArray *months;6 @property(nonatomic,strong)NSArray *days;7 8 @end
       
      

#import "ViewController.h"  2   3 @interface ViewController ()  4 @property (weak, nonatomic) IBOutlet UIPickerView *pickerView;  5   6 @end  7   8 @implementation ViewController  9  10 - (void)viewDidLoad 11 { 12     [super viewDidLoad]; 13     //初始化数据 14     NSMutableArray *multYears = [NSMutableArray array];//年 15     for(int i=0; i<20; i++) 16     { 17         NSString *year = [NSString stringWithFormat:@"20%02d年",i+1]; 18         [multYears addObject:year]; 19     } 20     self.years = multYears; 21      22     NSMutableArray *multMonths = [NSMutableArray arrayWithCapacity:12];//月 23     for(int i=1; i<=12; i++) 24     { 25         NSString *month = [NSString stringWithFormat:@"%d月",i]; 26         [multMonths addObject:month]; 27     } 28     self.months = multMonths; 29      30     NSMutableArray *multDays = [NSMutableArray arrayWithCapacity:31];//日 31     for(int i=1; i<=31; i++) 32     { 33         NSString *day = [NSString stringWithFormat:@"%d日",i]; 34         [multDays addObject:day]; 35     } 36     self.days = multDays; 37      38      39     //设置pickerView的数据源和代理 40     self.pickerView.dataSource = self; 41     self.pickerView.delegate = self; 42      43     //显示当前日期 44     NSDate *now = [NSDate date]; 45     //分解日期 46     NSCalendar  *calendar = [[NSCalendar alloc]initWithCalendarIdentifier:NSCalendarIdentifierGregorian]; 47      48     NSCalendarUnit unitFlags = NSCalendarUnitYear|NSCalendarUnitMonth|NSCalendarUnitDay; 49     NSDateComponents *components = [calendar components:unitFlags fromDate:now]; 50      51      52     //设置pickerView显示当前日期 53     NSInteger year = [components year]; 54     [self.pickerView selectRow:year-2000-1 inComponent:0 animated:year]; 55      56     NSInteger month = [components month]; 57     [self.pickerView selectRow:month-1 inComponent:1 animated:month]; 58      59     NSInteger day = [components day]; 60     [self.pickerView selectRow:day-1 inComponent:2 animated:day]; 61 } 62  63 #pragma mark - pickerView的代理方法 64 -(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView 65 { 66     return 3; 67 } 68 -(NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component 69 { 70     NSInteger row = 0; 71     switch (component) 72     { 73         case 0: 74             row = self.years.count; 75             break; 76         case 1: 77             row = self.months.count; 78             break; 79         case 2: 80             row = self.days.count; 81             break; 82     } 83     return  row; 84 } 85  86 -(NSString*)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component 87 { 88     NSString *title; 89     switch (component) 90     { 91         case 0: 92             title = self.years[row]; 93             break; 94         case 1: 95             title = self.months[row]; 96             break; 97         case 2: 98             title = self.days[row]; 99             break;100     }101     return  title;102 }103 -(void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component104 {105     NSString *strDate = [NSString stringWithFormat:@"%@-%@-%@",106                          self.years[[pickerView selectedRowInComponent:0]],107                          self.months[[pickerView selectedRowInComponent:1]],108                          self.days[[pickerView selectedRowInComponent:2]]];109     NSLog(@"%@",strDate);110 }111 @end

 

演示二：制作简单的字体表,包括字体类型、大小、颜色

源码如下：

1 #import 
      
       2 3 @interface ViewController : UIViewController
       
        4 @property(nonatomic,strong) NSArray *fontNames;5 @property(nonatomic,strong) NSArray *fontSizes;6 @property(nonatomic,strong) NSArray *fontColors;7 @end
       
      

#import "ViewController.h"  2   3 @interface ViewController ()  4 @property (weak, nonatomic) IBOutlet UILabel *label;  5 @property (weak, nonatomic) IBOutlet UIPickerView *pickerView;  6   7   8 @end  9  10 @implementation ViewController 11  12 - (void)viewDidLoad { 13     [super viewDidLoad]; 14     //初始化数据 15     self.fontNames = [UIFont familyNames];//字体名字 16      17     NSMutableArray *mutsize = [NSMutableArray arrayWithCapacity:20];//字体大小 18     for(int i=1; i<=30; i++) 19     { 20         [mutsize addObject:[NSString stringWithFormat:@"%d",10+i]]; 21     } 22     self.fontSizes = mutsize; 23      24     self.fontColors = @[ 25                         @{
     @"name":@"红色",@"color":[UIColor redColor]}, 26                         @{
     @"name":@"黑色",@"color":[UIColor blackColor]}, 27                         @{
     @"name":@"蓝色",@"color":[UIColor blueColor]}, 28                         @{
     @"name":@"黄色",@"color":[UIColor yellowColor]}, 29                         @{
     @"name":@"绿色",@"color":[UIColor greenColor]} 30                        ]; 31     //设置pickerView的代理和数据源 32     self.pickerView.dataSource = self; 33     self.pickerView.delegate = self; 34      35     //设置label的font 36     self.label.font = [UIFont fontWithName:self.fontNames[0] size:[self.fontSizes[0] integerValue]]; 37      38     self.label.textColor = [self.fontColors[0] objectForKey:@"color"]; 39 } 40  41 #pragma mark - pickerView的代理方法 42 -(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView 43 { 44     return  3; 45 } 46 -(NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component 47 { 48     NSInteger row = 0; 49     switch (component) 50     { 51         case 0: 52             row = self.fontNames.count; 53             break; 54         case 1: 55             row = self.fontSizes.count; 56             break; 57         case 2: 58             row = self.fontColors.count; 59             break; 60     } 61     return row; 62 } 63 -(NSString*)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component 64 { 65     NSString *title; 66     switch (component) 67     { 68         case 0: 69             title = self.fontNames[row]; 70             break; 71         case 1: 72             title = self.fontSizes[row]; 73             break; 74         case 2: 75             title = [self.fontColors[row] objectForKey:@"name"]; 76             break; 77     } 78     return  title; 79 } 80 //设置每一列的宽度 81 -(CGFloat)pickerView:(UIPickerView *)pickerView widthForComponent:(NSInteger)component 82 { 83     CGFloat width = 0.0f; 84     switch (component) 85     { 86         case 0: 87             width = pickerView.frame.size.width/2; 88             break; 89         case 1: 90             width = pickerView.frame.size.width/4; 91             break; 92         case 2: 93             width = pickerView.frame.size.width/4; 94             break; 95     } 96     return width; 97 } 98  99 -(void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component100 {101     //设置label的font102     self.label.font = [UIFont fontWithName:self.fontNames[[pickerView selectedRowInComponent:0]] size:[self.fontSizes[[pickerView selectedRowInComponent:1]] integerValue]];103     104     self.label.textColor = [self.fontColors[[pickerView selectedRowInComponent:2]] objectForKey:@"color"];105 }106 @end

　　

演示三：制作简单的图库浏览器

源码如下：

#import 
      
       @interface ViewController : UIViewController
       
        @end
       
      

#import "ViewController.h" 2  3 @interface ViewController () 4 @property (weak, nonatomic) IBOutlet UIPickerView *pickerView; 5 @property (strong,nonatomic)NSArray *imageNames; 6 @end 7  8 @implementation ViewController 9 10 - (void)viewDidLoad {11     [super viewDidLoad];12     //初始化数据13     NSMutableArray *mutImageNames = [NSMutableArray arrayWithCapacity:9];14     for(int i=0; i<9; i++)15     {16         [mutImageNames addObject:[NSString stringWithFormat:@"%d.png",i]];17     }18     self.imageNames = mutImageNames;19     20     //设置pickerView的数据源和代理21     self.pickerView.dataSource = self;22     self.pickerView.delegate = self;23     24 }25 #pragma mark - pickerview代理方法26 -(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView27 {28     return 1;29 }30 -(NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component31 {32     return self.imageNames.count;33 }34 //设置行高35 -(CGFloat)pickerView:(UIPickerView *)pickerView rowHeightForComponent:(NSInteger)component36 {37     UIImage *image = [UIImage imageNamed:self.imageNames[0]];38     return image.size.height;39 }40 //设置每行显示的视图41 -(UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view42 {43     UIImage *image = [UIImage imageNamed:self.imageNames[row]];44     //UIImageView *imageView = [[UIImageView alloc]initWithImage:image];45     //imageView.frame = CGRectMake(0, 0, image.size.width, image.size.height);46     //return imageView;47     48     UIButton *button = [[UIButton alloc]initWithFrame:CGRectMake(0, 0,image.size.width, image.size.height)];49     [button setBackgroundImage:image forState:UIControlStateNormal];50     [button addTarget:self action:@selector(buttonClicked:) forControlEvents:UIControlEventTouchUpInside];51     return button;52 }53 -(void)buttonClicked:(UIButton *)sender54 {55     NSLog(@"button clicked");56 }57 @end