iphone - UITextView 不响应另一个 UITextView 附件 View iPhone？

Question

我正在开发一个基于消息的 iPhone 应用程序。我有一个屏幕可以回复收到的消息。此屏幕包含两个 UITextView，如 bottomTextView 和 topTextView。

topTextView 添加为 bottomTextView 的 InputAccessory View 。

当用户进入屏幕时 topTextView 必须成为 FirstResponder。它正在显示，但光标未放置在 topTextView 中。光标位于 TextView bottomTextView 中。如何使 topTextView 成为第一响应者，光标就位？

这是我试过的代码:

- (void)viewDidLoad
{
    [super viewDidLoad];            
    bottomBarView = [[UIView alloc] initWithFrame:CGRectMake(0, 380, 320, 40)];
    bottomBarViewImage.image = [UIImage imageNamed: @"toolbarbg~iphone.png"];
    [bottomBarView addSubview: bottomBarViewImage];
    [self.view addSubview: bottomBarView];

    bottomTextView = [[UITextView alloc] initWithFrame:CGRectMake(35, 7.5, 210, 25)];
    bottomTextView.delegate = self;
    bottomTextView.backgroundColor = [UIColor clearColor];
    bottomTextView.font = [UIFont fontWithName:@"Helvetica" size:14];
    bottomTextView.scrollEnabled = NO;
    [bottomBarView addSubview: bottomTextView];

    topBarView = [[UIView alloc] initWithFrame:CGRectMake(0, 380, 320, 40)];
    topBarViewImage.image = [UIImage imageNamed: @"toolbarbg~iphone.png"];
    [topBarView addSubview: topBarViewImage];

    topTextView = [[UITextView alloc] initWithFrame:CGRectMake(35, 7.5, 210, 25)];
    topTextView.delegate = self;
    topTextView.backgroundColor = [UIColor clearColor];
    topTextView.font = [UIFont fontWithName:@"Helvetica" size:14];
    topTextView.scrollEnabled = NO;
    [topBarView addSubview: topTextView];

    [bottomTextView becomeFirstResponder];
    [bottomTextView setInputAccessoryView: topBarView];
}

-(void) textViewDidBeginEditing:(UITextView *)textView
{
    if(textView == bottomTextView)  
    {
        bottomTextView.scrollEnabled = NO;

        [topTextView becomeFirstResponder];
    }
}

带有 topBarView 的 topTextView 正在显示，但光标未放置在 topTextView 中。你能帮我解决这个问题吗？提前致谢。

Answer 1

我想可能是因为你在UITextView的delegate textViewDidBeginEditing:中调用了[topTextView becomeFirstResponder];。因此，只有当您开始编辑 bottomTextView 时，topTextView 才会成为第一响应者。尝试在 viewDidLoad 中调用 [topTextView becomeFirstResponder]; 而不是 [bottomTextView becomeFirstResponder];。看看进展如何。我不确定，但是 becomeFirstResponder 可能不会调用 textViewDidBeginEditing:。不确定它是否有效，但值得一试...

编辑:

我发现了一个相关的问题 here 。可能是因为textView没有马上出现，所以不能成为first responder。这是@Tom 接受的答案:

My solution: check when the keyboard (and thus the accessory view) appeared!

Step 1) Listen for the notification (make sure this code is read before you want to receive the notification).

[[NSNotificationCenter defaultCenter] addObserver:self 
                                         selector:@selector(changeFirstResponder)
                                             name:UIKeyboardDidShowNotification 
                                           object:nil];

Step 2) When the keyboard has appeared, you can set the textfield in your inputaccessoryview to become first responder:

-(void)changeFirstResponder
{
    [textField becomeFirstResponder]; //will return TRUE;
}