当我点击我的 UITextField 时如何显示 UIPickerView？答案

【问题标题】：How can I show a UIPickerView when I hit my UITextField?当我点击我的 UITextField 时如何显示 UIPickerView？
【发布时间】：2012-03-30 03:04:26
【问题描述】：

我从互联网上找到了很多示例代码，但也不起作用....谁能告诉我下面的编码有什么问题？多谢。求救

//我的存储板屏幕
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

【问题讨论】：

您是否将 UITextFieldDelegate 添加到 .h 和您的 UITextField 中？
在 textFieldDidBegin 中编写您的代码并提供委托

标签： ios cocoa-touch uitextfield uipickerview

【解决方案1】：

不要尝试通过滚动您自己的外观动画来模仿内置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，系统将为您制作动画：

textField.inputView = pickerView;

当您开始编辑文本字段时，选择器会在屏幕上为您显示动画。有关更多详细信息，请参阅我的回答 here，包括在顶部添加带有“完成”按钮的工具栏。

【讨论】：

动画出现时如何删除