UIActionSheet 中的键盘未键入任何内容

Question

我想知道为什么由 UITextField 打开的 iPhone 键盘除了文本字段本身内的删除键和清除按钮之外不输入任何内容。文本字段通过以下代码示例嵌入到 UIActionSheet 中：

// setup UITextField for the UIActionSheet
UITextField*    textField = [[UITextField alloc] initWithFrame:CGRectMake(8.0, 34.0, 304.0, 30.0)];
NSString*       startText = [[self.pathName lastPathComponent] stringByDeletingPathExtension];

textField.borderStyle     = UITextBorderStyleRoundedRect;
textField.backgroundColor = [UIColor whiteColor];
textField.clearButtonMode = UITextFieldViewModeAlways;
textField.text            = startText;
textField.delegate        = self;

[textField setKeyboardType:UIKeyboardTypeAlphabet];
[textField setKeyboardAppearance:UIKeyboardAppearanceAlert];

// setup UIActionSheet
UIActionSheet*  asheet = [[UIActionSheet alloc] initWithTitle: @"Please enter file name\n\n\n"
                                                     delegate: self
                                            cancelButtonTitle: @"Cancel"
                                       destructiveButtonTitle: nil
                                            otherButtonTitles: @"OK", nil];

if ([currentView isKindOfClass:[UIToolbar class]])
    [asheet showFromToolbar:(UIToolbar*)currentView];
else if ([currentView isKindOfClass:[UITabBar class]])
    [asheet showFromTabBar:(UITabBar*)currentView];
else
    [asheet showInView:currentView];

[asheet setFrame:CGRectMake(0.0, 60.0, 320.0, 380.0)];
[asheet insertSubview:textField atIndex:0];
[textField becomeFirstResponder];

// memory management
[textField release];
[asheet release];

我可以按 Shift 键，但按键不会更改为小写，它们始终为大写。好吧，我从未使用过带有操作表的文本字段......我在这里做错了什么？操作表和文本字段的委托方法似乎根据需要存在。

编辑： 我还更改了操作表的视图关联以及操作表的大小：

UIWindow*   appWindow = [UIApplication sharedApplication].keyWindow;

[asheet showInView:appWindow];
[asheet setFrame:CGRectMake(0.0, 60.0, 320.0, 204.0)];

while (CGRectEqualToRect(asheet.bounds, CGRectZero))
    ;

// Add the text field to action sheet
[asheet addSubview:textField];
[textField release];

现在键盘没有与操作表重叠（或“重叠”），操作表正确显示在状态栏和导航栏下方，并且键盘位于操作表下方，从下到上。

但只有 textFieldShouldBeginEditing 和 textFieldDidBeginEditing 被调用文本字段的委托方法，仅此而已。当我点击它时，Shift 键会发生变化，擦除键起作用，所有其他键都会在点击时显示自己 - 但不要插入到文本字段中。那么，这到底是怎么回事呢？

解决方案： 感谢 SVD 指出了这样一个事实：似乎不可能将 UITextField 嵌入到 UIActionSheet 中。因为我想要一个返回带有操作表的文件名字符串的方法（只是因为我更喜欢它的外观，而不是添加了文本字段的 UIAlertView），所以我花了更多的时间在它上面，终于找到了一个可行的解决方案。我在这里分享它是因为我意识到很多人都在寻找类似的东西。

要实现此功能，需要考虑两个主要方面：

• 文本字段不得是操作表的子视图，至少在 当它处于可编辑状态时，

• 操作表不应与键盘重叠

好的，代码来了。模态解决方案与第二个运行循环一起使用，因此可以处理文本字段和操作表的委托方法，而无需返回调用者 - 我确信这可以分解为传统方法，您可以在其中处理所有委托内容你自己的班级。

ModalAction.h：

#import <UIKit/UIKit.h>

@interface ModalAction : NSObject

+ (NSString*)ask: (NSString*)question
  withTextPrompt: (NSString*)prompt
      textPreset: (NSString*)preset
      dockToView: (UIView*)toView;

@end

ModalAction.m：

#import "ModalAction.h"

#define TEXT_FIELD_TAG      9999
#define ACTION_SHEET_TAG    8888

@interface ModalActionDelegate : NSObject <UIActionSheetDelegate, UITextFieldDelegate> 
{
    CFRunLoopRef    currentLoop;
    NSString*       text;
    NSUInteger      index;
}
@property (assign) NSUInteger index;
@property (retain) NSString* text;
@end


@implementation ModalActionDelegate
@synthesize index;
@synthesize text;

-(id)initWithRunLoop: (CFRunLoopRef)runLoop 
{
    if (self = [super init])
        currentLoop = runLoop;

    return self;
}

// Activate keyboard
- (void)acceptInput: (UIActionSheet*)actionSheet
{
    UITextField*    textField = (UITextField*)[actionSheet viewWithTag:TEXT_FIELD_TAG];
    UIWindow*       appWindow = [UIApplication sharedApplication].keyWindow;
    CGRect          frame     = textField.frame;

    [appWindow insertSubview:textField aboveSubview:actionSheet];
    frame.origin.y += 60.0; // move text field to same position as on action sheet
    textField.frame = frame;
    [textField becomeFirstResponder];
}

- (void)dealloc
{
    self.text = nil;
    [super dealloc];
}

#pragma mark -
#pragma mark === UIActionSheetDelegate ===
#pragma mark -

// User pressed button. Retrieve results
- (void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex
{
    NSLog(@"actionSheet clickedButtonAtIndex:%d", buttonIndex);
    UIWindow*       appWindow = [UIApplication sharedApplication].keyWindow;
    UITextField*    textField = (UITextField*)[appWindow viewWithTag:TEXT_FIELD_TAG];

    if (textField != nil)
        self.text = textField.text;

    self.index = buttonIndex;
    CFRunLoopStop(currentLoop);
}

#pragma mark -
#pragma mark === UITextFieldDelegate ===
#pragma mark -

- (BOOL)textFieldShouldBeginEditing:(UITextField*)textField
{
    NSLog(@"textFieldShouldBeginEditing");
    return YES;
}

- (void)textFieldDidBeginEditing:(UITextField*)textField
{
    NSLog(@"textFieldDidBeginEditing");
    [textField becomeFirstResponder];
}

- (BOOL)textFieldShouldEndEditing:(UITextField*)textField
{
    NSLog(@"textFieldShouldEndEditing");
    return YES;
}

- (void)textFieldDidEndEditing:(UITextField*)textField
{
    NSLog(@"textFieldDidEndEditing");
    [textField resignFirstResponder];
}

- (BOOL)textField:(UITextField*)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString*)string
{
    return YES;
}

- (BOOL)textFieldShouldClear:(UITextField*)textField
{
    NSLog(@"textFieldShouldClearEditing");
    return YES;
}

- (BOOL)textFieldShouldReturn:(UITextField*)textField
{
    NSLog(@"textFieldShouldReturn (%@)", textField.text);
    BOOL    hasSomeText = ![textField.text isEqualToString:@""];

    if (hasSomeText)
    {
        // send an OK to the action sheet
        UIWindow*       appWindow   = [UIApplication sharedApplication].keyWindow;
        UIActionSheet*  actionSheet = (UIActionSheet*)[appWindow viewWithTag:ACTION_SHEET_TAG];

        if (actionSheet != nil)
        {
            [actionSheet dismissWithClickedButtonIndex:0 animated:YES];
            self.text  = textField.text;
            self.index = 0;
            CFRunLoopStop(currentLoop);
            [textField resignFirstResponder];
        }
    }

    return hasSomeText;
}

@end


@implementation ModalAction

+ (NSString*)textQueryWith: (NSString*)question
                    prompt: (NSString*)prompt
                textPreset: (NSString*)preset
                   button1: (NSString*)button1
                   button2: (NSString*)button2
                   forView: (UIView*)toView
{
    // Create action sheet
    CFRunLoopRef            currentLoop = CFRunLoopGetCurrent();
    ModalActionDelegate*    madelegate  = [[ModalActionDelegate alloc] initWithRunLoop:currentLoop];
    NSString*               sheetTitle  = [question stringByAppendingString:@"\n\n\n"];
    UIActionSheet*          actionSheet = [[UIActionSheet alloc] initWithTitle: sheetTitle
                                                                      delegate: madelegate
                                                             cancelButtonTitle: button1
                                                        destructiveButtonTitle: nil
                                                             otherButtonTitles: button2, nil];
                            actionSheet.tag = ACTION_SHEET_TAG;

    // Build text field
    UITextField*    textField = [[UITextField alloc] initWithFrame:CGRectMake(8.0, 34.0, 304.0, 30.0)];

    textField.borderStyle = UITextBorderStyleRoundedRect;
    textField.tag         = TEXT_FIELD_TAG;
    textField.placeholder = prompt;
    textField.text        = preset;
    textField.delegate    = madelegate;
    textField.clearButtonMode          = UITextFieldViewModeWhileEditing;
    textField.keyboardType             = UIKeyboardTypeAlphabet;
    textField.keyboardAppearance       = UIKeyboardAppearanceAlert;
    textField.autocapitalizationType   = UITextAutocapitalizationTypeWords;
    textField.autocorrectionType       = UITextAutocorrectionTypeNo;
    textField.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter;
    textField.returnKeyType            = UIReturnKeyDone;

    // Show action sheet and wait for it to finish displaying
    UIWindow*   appWindow = [UIApplication sharedApplication].keyWindow;

    [actionSheet showInView:appWindow];
    [actionSheet setFrame:CGRectMake(0.0, 60.0, 320.0, 204.0)];

    while (CGRectEqualToRect(actionSheet.bounds, CGRectZero))
        ;

    // Add the text field to action sheet
    [actionSheet addSubview:textField];
    [textField release];

    // Set the field to first responder and move it into place
    [madelegate performSelector: @selector(acceptInput:) withObject: actionSheet];

    // Start the run loop
    CFRunLoopRun();

    // Retrieve the user choices
    NSUInteger  index  = madelegate.index;
    NSString*   answer = [[madelegate.text copy] autorelease];

    if (index == 1)
        answer = nil;   // assumes cancel in position 1

    [textField resignFirstResponder];
    [actionSheet release];
    textField.delegate = nil;
    [textField removeFromSuperview];
    [madelegate release];

    return answer;
}

+ (NSString*)ask: (NSString*)question
  withTextPrompt: (NSString*)prompt
      textPreset: (NSString*)preset
      dockToView: (UIView*)toView
{
    return [ModalAction textQueryWith: question
                               prompt: prompt
                           textPreset: preset
                              button1: NSLocalizedString(@"AlertBtnCancel", @"")
                              button2: @"OK"
                              forView: toView];
}

@end

它在模拟器 iOS 4.2 和真实设备的 iOS 4.0.2 上运行 - 我希望它对其他人也有帮助。

Answer 1

关于操作表的一个奇怪的事情是，例如，如果存在选项卡栏，则选项卡栏可能会“窃取”一些操作表点击，即使在视觉上操作表位于顶部。

您的操作表高 380 像素 - 因此当键盘滑出时，它会与操作表重叠。也许在这种情况下，是操作表窃取了键盘的敲击声？尝试使操作表更小并更靠近顶部 - 例如，为了测试我将其起始于 0、0 和 240 像素高的想法。

编辑：

显然这是一个问题 - 在没有选项卡栏或工具栏的简单测试应用程序中它对我不起作用。不过，我找到了这些链接：

使用警报视图执行此操作，它似乎有效（尽管它似乎仅适用于警报视图）：
https://discussions.apple.com/thread/1674641

这里有人制作自己的“行动表”改为：
如何在 UITextField 中启用文本输入UIActionSheet？