Question

我的观点中有两个文本。按下文本字段时，从底部显示UIPickerView或普通键盘（取决于文本文件的类型）。 UIScrollView包装了我视图中的所有内容 ViewController.h文件如下所示：

@interface MyViewController : UIViewController<UIPickerViewDataSource, UIPickerViewDelegate>

@property (weak, nonatomic) IBOutlet UIScrollView *scrollView;
@property (weak, nonatomic) IBOutlet UITextField *textNormal;
@property (weak, nonatomic) IBOutlet UITextField *textScroll;
@property UIPickerView * picker;

@end

我混合了一些代码来滚动浏览滚动视图，以便在显示键盘或选择器视图时显示文本字段。

ViewController.m文件：

@interface MyViewController ()

@property BOOL keyboardVisable;
@property CGPoint offset;
@property CGRect frame;
@property UIPickerView * picker;
@end

@implementation MyViewController

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.keyboardVisable = NO;
    [[NSNotificationCenter defaultCenter]
     addObserver:self selector:@selector(keyboardDidShow:) name:UIKeyboardDidShowNotification object:nil];
    [[NSNotificationCenter defaultCenter]
     addObserver:self selector:@selector(keyboardDidHide:) name:UIKeyboardDidHideNotification object:nil];

    UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(hideKeyboard)];
    tapGesture.cancelsTouchesInView = NO;
    [self.scrollView addGestureRecognizer:tapGesture];

    self.picker = [[UIPickerView alloc] init];
    self.textScroll.inputView = self.picker;
    self.picker.delegate = self;
    self.picker.dataSource = self;
    self.picker.showsSelectionIndicator = YES;

}
-(void)hideKeyboard
{
    NSLog(@"hide now");
    [self.scrollView endEditing:YES];
}


- (void)keyboardDidShow:(NSNotification *)notif{
    if(self.keyboardVisable)
        return;

    NSLog(@"keyboard did show");

    NSDictionary* info = [notif userInfo];
    NSValue* aValue = [info objectForKey:UIKeyboardFrameBeginUserInfoKey];
    CGSize keyboardSize = [aValue CGRectValue].size;

    // Save the current location so we can restore
    // when keyboard is dismissed
    self.offset = self.scrollView.contentOffset;
    self.frame = self.scrollView.frame;

    // Resize the scroll view to make room for the keyboard
    CGRect viewFrame = self.scrollView.frame;
    viewFrame.size.height -= keyboardSize.height;
    self.scrollView.frame = viewFrame;

    CGRect textFieldRect = [self.textScroll frame];
    textFieldRect.origin.y += 10;

    [self.scrollView scrollRectToVisible:textFieldRect animated:YES];

    // Keyboard is now visible
    self.keyboardVisable = YES;

}


- (void)keyboardDidHide:(NSNotification *)notif{
    if(!self.keyboardVisable)
        return;

    NSLog(@"keyboard did hide");


    //self.scrollView.contentOffset = self.offset;
    self.scrollView.frame = self.frame;
    [self.scrollView setContentOffset:self.offset animated:YES];

    self.keyboardVisable = NO;

}

这些代码在按下普通文本字段时正常工作（滚动视图会改变它的帧大小和偏移量，以便使文本字段可见，并且除了按下键盘之外的任何地方它将恢复正常）

但是，它们不能在带有inputView == pickerview的文本字段上工作。 scrollview会按预期更改其帧大小。一旦用户滚动了选择器视图，背景（scrollview）将突然滚动到顶部并意外地变为不可滚动。

谢谢！

在UIPickerView中滚动时，UIScrollView会出现意外行为

0 个答案: