IOS 5应用程序中的多个UIPickerView

时间：2012-05-23 15:15:53

标签： ios xcode uitextfield storyboard uipickerview

我大约两个月前开始学习iOS编程，到目前为止我很喜欢它，但我在UIPicker（s）和UIDatePickers中有点挣扎在我正在制作的应用程序中，我希望有人可能会指出我正确的方向。该应用程序应该模仿已经存在的PHP Web应用程序，这只不过是一个包含大量下拉菜单的表单。

假设我有GetAddressViewController，它将包含一堆输入字段。为简单起见，我可以说我只有3个输入字段：country，city和street。

用户应点击“国家/地区”输入字段，UIPicker会像键盘一样显示，选择国家/地区后，网络应用程序将返回该国家/地区所有城市的JSON数组。当用户点击“城市”输入字段时，重复相同的过程，UIPicker弹出一个返回城市列表，用户选择一条街道，UIPicker滑出，网络应用程序返回一系列街道等。

让我们说在我的GetAddressViewController.h文件中我有：

#import <UIKit/UIKit.h>

@interface GetAddressViewController : UIViewController
{
    UITextField *countryField;
    UITextField *cityField;
    UITextField *streetField;

    NSArray *countries;
    NSArray *cities;
    NSArray *streets;
}

@property(nonatomic, strong) IBOutlet UITextField *countryField;
@property(nonatomic, strong) IBOutlet UITextField *cityField;
@property(nonatomic, strong) IBOutlet UITextField *streetField;

@property(nonatomic, strong) IBOutlet NSArray *countries;
@property(nonatomic, strong) IBOutlet NSArray *cities;
@property(nonatomic, strong) IBOutlet NSArray *streets;

@end

在GetAddressViewController.m文件中我已经合成了属性，在故事板中我只有3个输入字段已经连接到适当的出口。 在我现有的代码中是否存在一些我应该注意的根本错误？

现在，我觉得在阅读有关选择器视图的教程时我遗漏了一些内容，因为我在StackOverflow上找到的大多数示例对我来说都没有多大意义。

有人能指出一个可以帮助我的基本类似例子。 UIPickers是否可行？还是有更好的方法？

我暂时没有感到这种无助，非常感谢任何帮助，谢谢

修改

好的我正在取得进步我希望我可以帮助其他有同样问题的人。 要使其工作并将pickerview连接到输入fileds inputView属性，您需要执行此操作。

对于.h文件，您需要添加两个委托：UIPickerViewDelegate和UIPickerViewDataSource 

@interface ViewController : UIViewController<UIPickerViewDelegate, UIPickerViewDataSource>{ ...

然后在你的.m文件中，你需要有这样的东西。我的wiewDidLoad方法中有这段代码。

UIPickerView *cityPicker = [[UIPickerView alloc] initWithFrame:CGRectZero];
    cityPicker.delegate = self;
    cityPicker.dataSource = self;
    [cityPicker setShowsSelectionIndicator:YES];
    cityField.inputView = cityPicker;

这只是意味着当您点击cityField时将显示cityPicker选择器视图。之后您需要添加以下pickerview委托方法，这些方法将为pickerview填充正确的数据。我的案例中的数据是一个包含城市列表的数组。

- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
{
    return 1;
}

- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
{
    return cities.count;
}

- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component
{
    return [cities objectAtIndex:row];
}

- (void) pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
{
    cityField.text = (NSString *)[cities objectAtIndex:row];
}

如果您希望隐藏UIPicker的“完成”，则需要此代码：

UIToolbar*  mypickerToolbar = [[UIToolbar alloc] initWithFrame:CGRectMake(0, 0, 320, 56)];
    mypickerToolbar.barStyle = UIBarStyleBlackOpaque;
    [mypickerToolbar sizeToFit];

    NSMutableArray *barItems = [[NSMutableArray alloc] init];

    UIBarButtonItem *flexSpace = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:self action:nil];
    [barItems addObject:flexSpace];

    UIBarButtonItem *doneBtn = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(pickerDoneClicked)];
    [barItems addObject:doneBtn];

    [mypickerToolbar setItems:barItems animated:YES];

    cityField.inputAccessoryView = mypickerToolbar;

添加一个新方法pickerDoneClicked 

-(void)pickerDoneClicked
{
    NSLog(@"Done Clicked");
    [cityField resignFirstResponder];
}

我希望这可以帮助别人。

2 个答案:

答案 0 :(得分：2)

您好请遵循多个pickerview的整个解决方案或只使用 - （void）createActionsheet 它可以解决您的问题

在.h

中定义 
UIActionSheet *actionSheet;
NSString *pickerType;
BOOL select

在.m中定义 

-(IBAction)countryBtnPressed:(id)sender
{
    [self createActionSheet];
    pickerType = @"picker";
    select = NO;
    UIPickerView *chPicker = [[UIPickerView alloc] initWithFrame:CGRectMake(0.0, 44.0, 0.0, 0.0)];
    chPicker.dataSource = self;
    chPicker.delegate = self;
    chPicker.showsSelectionIndicator = YES;
    [actionSheet addSubview:chPicker];
    Txt.text = [array objectAtIndex:0];
    [chPicker release];
}



-(IBAction)stateBtnPressed:(id)sender
    {
        [self createActionSheet];
        pickerType = @"statepicker";
        select = NO;
        UIPickerView *chPicker = [[UIPickerView alloc] initWithFrame:CGRectMake(0.0, 44.0, 0.0, 0.0)];
        chPicker.dataSource = self;
        chPicker.delegate = self;
        chPicker.showsSelectionIndicator = YES;
        [actionSheet addSubview:chPicker];
        stateTxt.text = [stateArray objectAtIndex:0];
        [chPicker release];
    }

/// Create Action Sheet
- (void)createActionSheet {
if (actionSheet == nil) {
    // setup actionsheet to contain the UIPicker
    actionSheet = [[UIActionSheet alloc] initWithTitle:@"Select"
                                              delegate:self
                                     cancelButtonTitle:nil
                                destructiveButtonTitle:nil
                                     otherButtonTitles:nil];

    UIToolbar *pickerToolbar = [[UIToolbar alloc] initWithFrame:CGRectMake(0, 0, 320, 44)];
    pickerToolbar.barStyle = UIBarStyleBlackOpaque;
    [pickerToolbar sizeToFit];

    NSMutableArray *barItems = [[NSMutableArray alloc] init];

    UIBarButtonItem *flexSpace = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:self action:nil];
    [barItems addObject:flexSpace];
    [flexSpace release];

    UIBarButtonItem *doneBtn = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(pickerDone:)];
    [barItems addObject:doneBtn];
    [doneBtn release];

    [pickerToolbar setItems:barItems animated:YES];
    [barItems release];

    [actionSheet addSubview:pickerToolbar];
    [pickerToolbar release];

    [actionSheet showInView:self.view];
    [actionSheet setBounds:CGRectMake(0,0,320, 464)];
}
}


#pragma mark UIPickerViewDelegate Methods

- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView {
    return 1;
}

- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
{
    int count;
    if ([pickerType isEqualToString:@"picker"])
        count = [array count];
    else if([pickerType isEqualToString:@"picker"])
            count = [statearray count];
return count;
}

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

    if ([pickerType isEqualToString:@"picker"])
        string = [array objectAtIndex:row];
    if ([pickerType isEqualToString:@"statepicker"])
        string = [statearray objectAtIndex:row];

return string;
}

// Set the width of the component inside the picker
- (CGFloat)pickerView:(UIPickerView *)pickerView widthForComponent:(NSInteger)component {
    return 300;
}

// Item picked
- (void)pickerView:(UIPickerView *)thePickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component {
    select = YES;
    if ([pickerType isEqualToString:@"picker"])
    {
        Txt.text = [array objectAtIndex:row];
    }
    if ([pickerType isEqualToString:@"statepicker"])
    {
        stateTxt.text = [statearray objectAtIndex:row];
    }

}

- (void)pickerDone:(id)sender
{
    if(select == NO)
    {
        if ([pickerType isEqualToString:@"picker"])
        {
            Txt.text = [array objectAtIndex:0];
        }
        else if ([pickerType isEqualToString:@"statepicker"])
        {
            stateTxt.text = [statearray objectAtIndex:0];
        }

}
    [actionSheet dismissWithClickedButtonIndex:0 animated:YES];
    [actionSheet release];
    actionSheet = nil;

}

}

答案 1 :(得分：1)

UIPickers可以使用，但在这种特殊情况下，条目列表可以是一个非常长的列表，并且条目有时可能不仅仅是一个简单的字符串，例如，如果国家名称是“津巴布韦共和国，非洲“或UIPicker控制器之类的东西无法以最佳方式显示数据。您可以使用表视图并以模态方式显示它们。如果条目列表超过一百个，Tableviews会为您提供更好的选择方法。

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