弹出 UIPickerView (iphone)

Question

我正在创建一个 textField，当单击 UIPickerView 时会出现。 当我运行此代码时出现错误： 线程1：Profram接收信号：“SIGABRT”。

我对 iPhone 开发还很陌生，但负责人不在，我正在接一个项目。

如果您能让我知道这有什么问题...

这是 ViewController.h 的样子：

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController {

IBOutlet UIPickerView *picker;
IBOutlet UITextField *text;

}


- (IBAction)showPicker:(id)sender;


@end

和 ViewController.m：

#import "ViewController.h"
@implementation ViewController
- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Release any cached data, images, etc that aren't in use.
}

#pragma mark - View lifecycle

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
}

- (void)viewDidUnload
{
    [super viewDidUnload];
    // Release any retained subviews of the main view.
     // e.g. self.myOutlet = nil;
 }

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
}

- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];
}

- (void)viewWillDisappear:(BOOL)animated
{
    [super viewWillDisappear:animated];
}


- (void)viewDidDisappear:(BOOL)animated
{
[super viewDidDisappear:animated];
}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
// Return YES for supported orientations
if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone) {
    return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
} else {
    return YES;


}
}

- (void)showPicker {

[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:0.4];
[UIView setAnimationDelegate:self];
picker.center = CGPointMake(160, 240);
[UIView commitAnimations];


if (!self.navigationItem.rightBarButtonItem) {
    UIBarButtonItem *doneButton = [[UIBarButtonItem alloc]     initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(done:)];
    [self.navigationItem setRightBarButtonItem:doneButton animated:YES];
  //  [doneButton release];
}   
}


- (void)hidePicker {

[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:0.4];
[UIView setAnimationDelegate:self];
picker.center = CGPointMake(160, 240);
[UIView commitAnimations];


[self.navigationItem setRightBarButtonItem:nil animated:YES];
}


- (void)done:(id)sender {

[self hidePicker];

[self.navigationItem setRightBarButtonItem:nil animated:YES];
}


- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField {

[self showPicker];

return NO;
}

Answer 1

- (IBAction)showPicker:(id)sender;

这个函数没有在你的 .m 文件中实现，而是使用上面的 -(void) showPicker...

以及这个有什么用...

- (void)done:(id)sender

Answer 2

选择器视图必须有一个数据源来获取要显示的数据和一个委托来响应事件。通常，我会通过采用相应的协议 UIPickerViewDelegate 和 UIPickerViewDataSource 将控制器定义为两者。您的控制器没有，这可能意味着数据源和委托位于另一个对象内。您应该检查界面生成器，紧紧单击选择器，然后查看出现的委托和数据源。如果您发现控制器以外的其他类，那么您应该在其中查找错误。如果您找到控制器的类，那么问题是您没有实现填充选择器视图的方法。作为参考，选择器至少正在寻找数据源方法：

- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view

祝狩猎好运。