IOS中的各种Picker

简述

在应用的一些设置中经常要用到一些Picker来快速帮助用户选定取值，一般会用到的有UIDatePicker，UIPickerView以及UIImagePickerController。

初始界面

如图，在搭建好的界面，实现方法来完成各个选择。首先是日期选择

UIDatePicker

主要需要设置的属性有

locale

datePickerMode

    UIDatePicker *datePicker = [[UIDatePicker alloc] init];

    datePicker.locale = [[NSLocale alloc] initWithLocaleIdentifier:@"zh_Hans_cn"];

    datePicker.datePickerMode = UIDatePickerModeDate;

    NSString *stdDate = @"1990-01-01";

    NSDateFormatter *formatter = [[NSDateFormatter alloc] init];

    formatter.dateFormat = @"yyyy-MM-dd";

    [datePicker setDate:[formatter dateFromString:stdDate] animated:YES];

    [datePicker addTarget:self action:@selector(showDate:) forControlEvents:UIControlEventValueChanged];

    _dateField.inputView = datePicker;

    _dateField.text = stdDate;

在这里，我们也对它的初始日期进行了设置。

对齐事件进行监听即可达到目的，并没有代理协议。

- (void)showDate:(UIDatePicker *)datePicker

{

    NSDate *date = datePicker.date;

    NSDateFormatter *formatter = [[NSDateFormatter alloc] init];

    formatter.dateFormat = @"yyyy-MM-dd";

    NSString *outputString = [formatter stringFromDate:date];

    _dateField.text = outputString;

}

UIImagePickerController

如果不自定义选取照片视图的话，实现照片或者拍照选取功能十分简单，设置
协议就可以快速调用。

    UIImagePickerController *imagePC = [[UIImagePickerController alloc] init];

    //从照片库中选择图片， 也可以设置相机

    imagePC.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;

    //允许对图片进行简单的编辑

    imagePC.allowsEditing = YES;

    imagePC.delegate = self;

    [self presentViewController:imagePC animated:YES completion:nil];

协议方法获取图片并进行设置

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info

{

    const NSString *REditedImageIdentifier = @"UIImagePickerControllerEditedImage";

    UIImage *image = info[REditedImageIdentifier];

    [_imageButton setImage:image forState:UIControlStateNormal];

    [picker dismissViewControllerAnimated:YES completion:nil];

}

UIPickerView

在Component较多的时候，PickerView稍微要复杂一些。首先初始化和设置属性

- (void)pickerViewAndMethod

{

    UIPickerView *pickerView = [[UIPickerView alloc] init];

    pickerView.delegate = self;

    pickerView.dataSource = self;

    //显示选择活动器

    pickerView.showsSelectionIndicator = YES;

    _cityField.inputView = pickerView;

    _cityField.text = @"北京 - 海淀";

}

实现数据源和代理方法，来刷新自身数据和界面。

- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView

{

    return rComponentCount;

}

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

{

    if (component == rProvinceComponent)

    {

        return _cityList.count;

    }

    else

    {

        NSInteger i = [pickerView selectedRowInComponent:rProvinceComponent];

        NSArray *arr = _cityList[i][@"city"];

        return arr.count;

    }

}

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

{

    if (component == rProvinceComponent)

    {

        NSString *proName = _cityList[row][@"province"];

        return proName;

    }

    else

    {

        NSInteger i = [pickerView selectedRowInComponent:rProvinceComponent];

        NSString *cityName = _cityList[i][@"city"][row];

        return cityName;

    }

}

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

{

    [pickerView reloadComponent:rCityComponent];

    NSInteger proIndex = [pickerView selectedRowInComponent:rProvinceComponent];

    NSString *proName = _cityList[proIndex][@"province"];

    NSInteger cityIndex = [pickerView selectedRowInComponent:rCityComponent];

    NSString *cityName = _cityList[proIndex][@"city"][cityIndex];

    _cityField.text = [NSString stringWithFormat:@"%@ - %@", proName, cityName];

}

数据源来自于自己写的一个简单的Plist文件。一个数组中包含多个字典。

这样一个使用各种Picker进行设置的功能就完成了。

demo示例点击打开链接

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巴特西

IOS中的各种Picker

简述

UIDatePicker

UIImagePickerController

UIPickerView

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