[英]How to export the selection of a UIPickerView object to a CSV file?
我正在编写一个小型iOS应用程序,希望对我的现场工作有所帮助。 我在OS X El Capitan 10.11.4上,使用Xcode 7.3并为iOS 9.3编写应用程序。
这是整个想法:我不想将数据插入纸中,而是将所有内容都写到了要在iPad上使用的基本表单形式的应用程序中,然后让该应用程序将数据传输到.csv文件中。
我已经弄清了几乎所有东西(应用程序的结构,传输和检索数据的协议等),但是有一件事情使我发疯。 在向您展示我正在使用的代码之前,这是问题所在。 当我单击“保存”按钮,然后再去检查已保存的数据时,我无法获得UIPickerView对象选择的值以将其传输到.csv文件。 其他一切正常。 我有两个UIPickerView对象。 我有一个性别信息,编码为M,F和M / F。 另一个具有关于年龄的信息,编码为Adu,Juv,Hat。 我想要的是该应用程序保存所选的值,但我不太清楚。
任何帮助深表感谢。 谢谢。
这是我用于ViewController.h的代码
#import <UIKit/UIKit.h>
@interface ViewController : UIViewController<UIPickerViewDataSource, UIPickerViewDelegate>
@property (strong, nonatomic) IBOutlet UIDatePicker *day;
@property (strong, nonatomic) IBOutlet UITextField *species;
@property (strong, nonatomic) IBOutlet UITextField *island;
@property (strong, nonatomic) IBOutlet UITextField *cay;
@property (strong, nonatomic) IBOutlet UITextField *pit;
@property (strong, nonatomic) IBOutlet UITextField *coordinatesN;
@property (strong, nonatomic) IBOutlet UITextField *coordinatesW;
@property (strong, nonatomic) IBOutlet UIPickerView *sex;
@property (strong, nonatomic) IBOutlet UIPickerView *age;
- (IBAction)saveInfo:(id)sender;
- (IBAction)retrieveInfo:(id)sender;
- (IBAction)retractKeyboard:(id)sender;
@property (strong, nonatomic) IBOutlet UITextView *resultView;
@end
这是我用于ViewConntroller.m的代码
#import "ViewController.h"
@interface ViewController ()
{
NSArray *pickerDataSex;
NSArray *pickerDataAge;
}
@end
@implementation ViewController
@synthesize resultView;
@synthesize day;
@synthesize species;
@synthesize island;
@synthesize cay;
@synthesize pit;
@synthesize coordinatesW;
@synthesize coordinatesN;
@synthesize sex;
@synthesize age;
- (IBAction)retractKeyboard:(id)sender {
[self resignFirstResponder];
}
- (IBAction)saveInfo:(id)sender {
NSString *resultLine=[NSString stringWithFormat:@"%@,%@,%@,%@,%@,%@,%@,%@,%@\n",
self.day.date,
self.species.text,
self.island.text,
self.cay.text,
self.pit.text,
self.coordinatesN.text,
self.coordinatesW.text,
self.sex.dataSource,
self.age.dataSource];
NSString *docPath =[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES )objectAtIndex:0];
//resultView.text = docPath;}
NSString *surveys=[docPath stringByAppendingPathComponent:@"results.csv"];
if (![[NSFileManager defaultManager] fileExistsAtPath:surveys]) {
[[NSFileManager defaultManager] createFileAtPath:surveys contents:nil attributes:nil];
}
NSFileHandle *fileHandle = [NSFileHandle fileHandleForUpdatingAtPath:surveys];
[fileHandle seekToEndOfFile];
[fileHandle writeData:[resultLine dataUsingEncoding:NSUTF8StringEncoding]];
[fileHandle closeFile];
self.species.text=@"";
self.island.text=@"";
self.cay.text=@"";
self.pit.text=@"";
self.coordinatesN.text=@"";
self.coordinatesW.text=@"";
NSLog(@"info saved");
}
- (IBAction)retrieveInfo:(id)sender {
NSString *docPath =[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES )objectAtIndex:0];
//resultView.text = docPath;
NSString *surveys=[docPath stringByAppendingPathComponent:@"results.csv"];
if ([[NSFileManager defaultManager] fileExistsAtPath: surveys]) {
NSFileHandle *fileHandle = [NSFileHandle fileHandleForReadingAtPath:surveys];
NSString *surveyResults = [[NSString alloc]initWithData:[fileHandle availableData] encoding:NSUTF8StringEncoding];
[fileHandle closeFile];
self.resultView.text = surveyResults;
}
}
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
//Initialize picker data
pickerDataSex = @[@"M",@"F",@"M/F"];
pickerDataAge = @[@"Adu",@"Juv",@"Hat"];
//Connect data to picker
self.sex.dataSource = self;
self.sex.delegate = self;
self.age.dataSource = self;
self.age.delegate = self;
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
//Number of columns of the data
- (NSInteger)numberOfComponentsInPickerView: (UIPickerView *)pickerView
{
if (pickerView==self.sex){
return 1;
} else if (pickerView==self.age){
return 1;
}
return 0;
}
//Number of rows of data
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
{
if (pickerView==self.sex){
return pickerDataSex.count;
} else if (pickerView==self.age){
return pickerDataAge.count;
}
return 0;
}
//The data to return for the row and component (column) that's being passed
-(NSString*)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component
{
if (pickerView==self.sex){
return pickerDataSex[row];
} else if (pickerView==self.age){
return pickerDataAge[row];
}
return 0;
}
@end
您可以通过以下方式从UIPickerViews
中获取值:
NSInteger selectedRowSex = [self.sex selectedRowInComponent:0];
NSInteger selectedRowAge = [self.age selectedRowInComponent:0];
NSString *selectedSex = [pickerDataSex objectAtIndex:selectedRowSex];
NSString *selectedAge = [pickerDataAge objectAtIndex:selectedRowAge];
然后
NSString *resultLine = [NSString stringWithFormat:@"%@,%@,%@,%@,%@,%@,%@,%@,%@\n",
self.day.date,
self.species.text,
self.island.text,
self.cay.text,
self.pit.text,
self.coordinatesN.text,
self.coordinatesW.text,
selectedSex,
selectedAge];
您具有填充选择器视图的代码,但未显示任何从选择器视图获取选定值的代码。
处理该问题的最简单方法是在您的saveInfo方法中添加代码,该方法在您的选择器视图上调用selectedRowInComponent
来获取当前值。
或者,您可以实现pickerView:didSelectRow:inComponent
委托方法,并在每次更改时读取新选择的选择器值。
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