iOS-UIPickerView餐廳點餐系統

2019-11-14 20:40:44

字體：大中小

來源：轉載

供稿：網友

在餐廳里的點餐系統的核心控件就是UipickerView

今天晚上在整理以前的項目筆記時，特意把UIPickerView單獨拿出來，做了一個簡陋的點餐道具。

因為沒有素材圖片，所有大家將就看看吧

0.用到的主要方法　　

- 數據源方法

有多少列- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView{    return _foods.count;}第component列有多少行- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component{    NSArray *array = _foods[component];        return array.count;}每行顯示什么內容、第component列第row行顯示什么文字- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component{    return _foods[component][row];}-  代理方法
選中了第component列第row行就會調用// 只有手動選中了某一行才會通知代理- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component{ 2.選中某一行
[_pickerView selectRow:index inComponent:component animated:YES];

1.UI界面搭建，將需要用到的控件拖入頭文件　　

UIPickerView

@interface ViewController : UIViewController@PRoperty (weak, nonatomic) IBOutlet UIPickerView *pickerView;@property (weak, nonatomic) IBOutlet UILabel *fruit;@property (weak, nonatomic) IBOutlet UILabel *meat;@property (weak, nonatomic) IBOutlet UILabel *water;- (IBAction)randomFood:(id)sender;@end

2.初始化數據　　

記得實現數據源和代理

<UIPickerViewDataSource, UIPickerViewDelegate>

@interface ViewController () <UIPickerViewDataSource, UIPickerViewDelegate>{    NSArray *_foods;}@end@implementation ViewController- (void)viewDidLoad{    [super viewDidLoad];        // 1.加載數據    _foods = [NSArray arrayWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"foods.plist" ofType:nil]];        // 2.設置默認值//    _fruit.text = _foods[0][0];//    _meat.text = _foods[1][0];//    _water.text = _foods[2][0];    int count = _foods.count;    for (int i = 0; i < count; i++) {        [self pickerView:nil didSelectRow:0 inComponent:i];    }}

3.實現數據源方法用于展示數據　　

#pragma mark - 數據源#pragma mark 有多少列- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView{    return _foods.count;}#pragma mark 第component列有多少行- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component{    NSArray *array = _foods[component];        return array.count;}#pragma mark 每行顯示什么內容、第component列第row行顯示什么文字- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component{    return _foods[component][row];}

4.實現代理方法，當選定時更新UI界面　　

#pragma mark - 代理#pragma mark 選中了第component列第row行就會調用// 只有手動選中了某一行才會通知代理- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component{    // 1.取出選中那行的文字    NSString *text = _foods[component][row];        // 2.顯示到對應的label上面    if (component == 0) { // 水果        _fruit.text = text;    } else if (component == 1) { // 肉        _meat.text = text;    } else { // 飲料        _water.text = text;    }}

5.實現隨機點餐功能　　

#pragma mark 隨機- (IBAction)randomFood:(id)sender {    // 1.隨機選中第0列的某一行（水果）//    [self randomCompoment:0];//    //    // 2.隨機選中第1列的某一行（肉）//    [self randomCompoment:1];//    //    // 3.隨機選中第2列的某一行（飲料）//    [self randomCompoment:2];        int count = _foods.count;    for (int i = 0; i < count; i++) {        [self randomCompoment:i];    }}#pragma mark 隨機選中某一列的方法- (void)randomCompoment:(int)component{    // 0.獲得第component列選中的行號    int selectedRow = [_pickerView selectedRowInComponent:component];        // 1.隨機生成行號    int index = selectedRow;    while (index == selectedRow) {        index = arc4random_uniform([_foods[component] count]);    } // 一定會生成不一樣的行號        // 2.選中某一行    [_pickerView selectRow:index inComponent:component animated:YES];        // 3.更改文字    [self pickerView:nil didSelectRow:index inComponent:component];}