UIPickerView基本用法

来源：互联网发布：安装软件出现2503 编辑：程序博客网时间：2024/05/16 14:35

UIPickerView不仅可以将UIDatePicker作为其选项，还可以将各种字符串、各种UIView的子类追加到UIPickerView中

1、基本用法：

#import "ViewController.h"@interface ViewController () <UIPickerViewDataSource, UIPickerViewDelegate>@end@implementation ViewController- (void)viewDidLoad {    [super viewDidLoad];    // Do any additional setup after loading the view, typically from a nib.    self.view.backgroundColor = [UIColor whiteColor];        UIPickerView * pickerView = [[UIPickerView alloc] init];    pickerView.dataSource = self;    pickerView.delegate = self;    [self.view addSubview:pickerView];    pickerView.frame = CGRectMake(50, 100, 300, 200);    pickerView.backgroundColor = [UIColor grayColor];        }#pragma mark --#pragma mark UIPickerViewDataSource- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView {    //返回列    return 4;}- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component {    //返回行    return 20;}#pragma mark UIPickerViewDelegate//返回需要显示的字符- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component {    return [NSString stringWithFormat:@"%ld-%ld", (long)row, (long)component];}

2、获取选择行的信息：

#pragma mark UIPickerViewDelegate//每次任何一列停止滚动就调用此方法- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component {    NSInteger c0 = [pickerView selectedRowInComponent:0];    NSInteger c1 = [pickerView selectedRowInComponent:1];    NSInteger c2 = [pickerView selectedRowInComponent:2];    NSInteger c3 = [pickerView selectedRowInComponent:3];    NSString * str = [NSString stringWithFormat:@"%li-%li-%li-%li", (long)c0, (long)c1, (long)c2, (long)c3];    NSLog(@"%@", str);}

输出：

2015-11-30 12:55:37.225 07-uipickerView[2741:48628] 3-0-0-02015-11-30 12:58:41.227 07-uipickerView[2741:48628] 3-6-0-02015-11-30 12:58:45.161 07-uipickerView[2741:48628] 3-6-10-02015-11-30 12:58:48.923 07-uipickerView[2741:48628] 3-6-10-8

3、追加UIView

#import "ViewController.h"@interface ViewController () <UIPickerViewDataSource, UIPickerViewDelegate>{    UIPickerView * _pickerView;    NSArray * _dataSource;}@end@implementation ViewController- (void)viewDidLoad {    [super viewDidLoad];    // Do any additional setup after loading the view, typically from a nib.    self.view.backgroundColor = [UIColor whiteColor];        _pickerView = [[UIPickerView alloc] init];    _pickerView.dataSource = self;    _pickerView.delegate = self;    [self.view addSubview:_pickerView];    _pickerView.frame = CGRectMake(50, 100, 300, 200);    _pickerView.backgroundColor = [UIColor grayColor];        _pickerView.showsSelectionIndicator = YES; //明确选中的行            UIImage * image1 = [UIImage imageNamed:@"wallpaper_01.jpg"];    UIImage * image2 = [UIImage imageNamed:@"wallpaper_02.jpg"];    UIImage * image3 = [UIImage imageNamed:@"wallpaper_03.jpg"];    UIImage * image4 = [UIImage imageNamed:@"wallpaper_04.jpg"];    NSArray * array1 = @[image1, image2, image3, image4];    NSArray * array2 = @[image1, image2, image3, image4];    NSArray * array3 = @[image1, image2, image3, image4];    _dataSource = @[array1, array2, array3];}#pragma mark --#pragma mark UIPickerViewDataSource- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView {    //返回列    return 3;}- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component {    //返回行    return 4;}#pragma mark UIPickerViewDelegate- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view {    UIImageView * imageView = (UIImageView *) view;    if (!imageView) {        UIImage * image = _dataSource[component][row];        imageView = [[UIImageView alloc] initWithImage:image];    }    return imageView;}

图片搞的太小了，看的有点不清：

- (nullable UIView *)viewForRow:(NSInteger)row forComponent:(NSInteger)component;

可以用此方法得到当前选择行中的UIView

4、返回选择行的每个UIView的高和宽

#pragma mark UIPickerViewDelegate- (CGFloat)pickerView:(UIPickerView *)pickerView widthForComponent:(NSInteger)component {    //列宽度    if (component == 0) {        return 150;    }else {        return 75;    }}- (CGFloat)pickerView:(UIPickerView *)pickerView rowHeightForComponent:(NSInteger)component {    return 70;}

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