当我点击UITextField时如何显示UIPickerView？

Question

我从互联网上找到了很多示例代码,但也没有用....任何人都可以告诉我下面编码的错误是什么？非常感谢.SOS

//我的商店屏幕
http://imageupload.org/en/file/209300/03.jpg.html

//This is PickerViewTest.h

@interface InputRound : UIViewController<UITextFieldDelegate>
{
    UIPickerView *pvPickerTest;
    NSMutableArray *aryMaster;
}

@property (nonatomic, retain) IBOutlet UIPickerView *pvPickerTest; 
@property (nonatomic, retain) NSMutableArray *aryMaster;

@end


//This is PickerViewTest.m

@interface InputRound ()

@end

@implementation PickerViewTest

@synthesize pvPickerTest, aryMaster;

-(id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

-(void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view.

    aryMaster = [[NSMutableArray alloc] init];

    [aryMaster addObject:@"User01"];
    [aryMaster addObject:@"User02"];
    [aryMaster addObject:@"User03"];    
}

-(NSInteger)numberOfComponentsInPickerView:(NSInteger)component
{
    return 1;
}

-(NSInteger)pickerView:(UIPickerView *)picker numberOfRowsInComponent:(NSInteger)component
{
    return [aryMaster count];
}

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

-(void)viewDidUnload
{
    [super viewDidUnload];
    // Release any retained subviews of the main view.
}

-(BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    return (interfaceOrientation == UIInterfaceOrientationPortrait);
}

-(BOOL)textFieldShouldBeginEditing:(UITextField *)textField
{
    // Show UIPickerView
    pvPickerTest.frame = CGRectMake(0, 500, pvPickerTest.frame.size.width,     pvPickerTest.frame.size.height);

    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:.50];
    [UIView setAnimationDelegate:self];

    pvPickerTest.frame = CGRectMake(0, 200, pvPickerTest.frame.size.width, pvPickerTest.frame.size.height);
    [self.view addSubview:pvPickerTest];
    [UIView commitAnimations];    
    return NO;
}

@end

Answer 1

不要试图通过滚动自己的外观动画来模仿内置的动画来重新发明轮子.将选择器视图设置为文本字段的输入视图,系统将为您执行动画:

textField.inputView = pickerView;

当您开始编辑文本字段时,选择器会在屏幕上为您设置动画.见我的答案在这里了解更多详情,包括顶部添加工具栏与"完成"按钮.