iOS鍵盤可點擊但不可見

Question

我正在制作一個允許用戶提問的應用程序。 在我的addQuestion類中，我有一個UITextView，用戶可以在其中寫下他們的問題。

我的問題是，有時候我的iPhone上的鍵盤是看不見的（並非每次都發生這種情況-僅在我第一次打開該應用程序時-有時甚至可以立即使用）。 奇怪的是，我仍然可以按鍵盤上的鍵，並根據鍵盤可見的位置鍵入響應。 問題僅在於可見性（我嘗試移動UITextView以便不會阻塞鍵盤）。 大約20或25秒后，鍵盤出現。

我還使用了蘋果推薦的故障排除方法：

for (UIWindow *window in [[UIApplication sharedApplication] windows]) {
        NSLog(@"isKeyWindow = %d window level = %.1f frame = %@ class = %@\n",
              window.isKeyWindow, window.windowLevel,
              NSStringFromCGRect(window.frame), window.class.description);
    }

但是沒有覆蓋UITextEffectsWindow的自定義窗口

它輸出：

isKeyWindow = 1 window level = 0.0 frame = {{0, 0}, {375, 667}} class = UIWindow**

isKeyWindow = 0 window level = 10.0 frame = {{0, 0}, {375, 667}} class = UITextEffectsWindow**

當它最終工作並且鍵盤可見時：

isKeyWindow = 1 window level = 0.0 frame = {{0, 0}, {375, 667}} class = UIWindow

isKeyWindow = 0 window level = 1.0 frame = {{0, 0}, {375, 667}} class = UITextEffectsWindow

也許與窗口級別為10.0有關嗎？ 當鍵盤最終顯示時，窗口級別為1.0 ...

這是.m類，以獲取更多信息

    @interface addQuestion () <UITextViewDelegate>
    @property (weak, nonatomic) IBOutlet UITextView *questionText;
    @property (strong, nonatomic) NSDictionary *dictionary;

    @end

@implementation addQuestion

- (void)viewDidLoad {
    [super viewDidLoad];



    // Do any additional setup after loading the view.
    [self.questionText becomeFirstResponder];
    self.questionText.delegate = self;
    self.questionText.text = @"Ask a good yes or no question!";
    self.questionText.textColor = [UIColor lightGrayColor];

    UIBarButtonItem *anotherButton = [[UIBarButtonItem alloc] initWithTitle:@"Post" style:UIBarButtonItemStylePlain target:self action:@selector(posted)];
    self.navigationItem.rightBarButtonItem = anotherButton;


//    for (UIWindow *window in [[UIApplication sharedApplication] windows]) {
//        NSLog(@"isKeyWindow = %d window level = %.1f frame = %@ class = %@\n",
//              window.isKeyWindow, window.windowLevel,
//              NSStringFromCGRect(window.frame), window.class.description);
//    }
}

- (void)textViewDidChangeSelection:(UITextView *)textView{
    if ([textView.text isEqualToString:@"Ask a good yes or no question!"] && [textView.textColor isEqual:[UIColor lightGrayColor]])[textView setSelectedRange:NSMakeRange(0, 0)];

}

- (void)textViewDidBeginEditing:(UITextView *)textView{

    [textView setSelectedRange:NSMakeRange(0, 0)];
}

- (void)textViewDidChange:(UITextView *)textView
{
    if (textView.text.length != 0 && [[textView.text substringFromIndex:1] isEqualToString:@"Ask a good yes or no question!"] && [textView.textColor isEqual:[UIColor lightGrayColor]]){
        textView.text = [textView.text substringToIndex:1];
        textView.textColor = [UIColor blackColor]; //optional
        self.navigationItem.leftBarButtonItem.enabled=YES;


    }
    else if(textView.text.length == 0){
        self.navigationItem.leftBarButtonItem.enabled=NO;
        textView.text = @"Ask a good yes or no question!";
        textView.textColor = [UIColor lightGrayColor];
        [textView setSelectedRange:NSMakeRange(0, 0)];
    }
}

- (void)textViewDidEndEditing:(UITextView *)textView
{
    if ([textView.text isEqualToString:@""]) {
        textView.text = @"Ask a good yes or no question!";
        textView.textColor = [UIColor lightGrayColor]; //optional
    }
    //[textView resignFirstResponder];
}

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text{
    if (text.length > 1 && [textView.text isEqualToString:@"Ask a good yes or no question!"]) {
        textView.text = @"";
        textView.textColor = [UIColor blackColor];
    }

    if([[textView text] length] > 140){
        return NO;
    } else {
        return YES;
    }
}
- (BOOL)canBecomeFirstResponder {
    return YES;
}  



@end

Answer 1

[self.questionText becomeFirstResponder];
remove this

Answer 2

我的問題是我嘗試在后台線程中進行篩選（在NSURLSession進行回調之后）。

我應該做的是確保在主線程中調用了segue。

dispatch_async(dispatch_get_main_queue(), ^{
                [self performSegueWithIdentifier:@"proceed" sender:self];
            });