连接外部键盘时支持命令，控制和箭头键 [英] Support command, control and arrow keys when an external keyboard is attached

问题描述

我有一个iOS应用程序，我想要做的就是提供更多支持基本命令键组合，如命令+ a，命令+ s，命令+ x，命令+ v和朋友，当用户连接蓝牙键盘时。

I have an iOS app where all I want to do is provide more support for basic command key combinations such as command+a, command+s, command+x, command+v and friends when a user has connected a bluetooth keyboard.

我知道这是可能的。诸如Textastic和许多其他编辑应用程序之类的应用程序支持这些功能。

I know this is possible. Applications such as Textastic and many other editing apps support these features.

我查看了UIResponder（它似乎只在弹出菜单中使用），UIKeyInput， UITextInput [Delegate]和其他API文档没有参考如何执行此操作。

I have looked at UIResponder (which appears to only be used by the pop-up menu), UIKeyInput, UITextInput[Delegate] and other API docs with no reference to how to do this.

使用（BOOL）canPerformAction很容易支持在UIMenuController中显示哪些选项： （SEL）动作withSender：（id）发件人。但是，当连接蓝牙键盘时，似乎不会调用此方法。因此，我需要专门为键盘或其他方法实现另一种方法。

It is easy to support which options are displayed in the UIMenuController using (BOOL)canPerformAction:(SEL)action withSender:(id)sender. However, this method does not appear to be called when a bluetooth keyboard is attached. So I either need to implement another method specifically for the keyboard or something else.

我现在怀疑文本子系统可能负责执行操作。但是，我找不到任何文件！此外，执行操作时不会调用任何UITextInput委托方法。我几乎认为解决方案是私有的，我需要特别询问Apple如何访问这些功能（我刚刚完成）。

I now suspect it could be that the text subsystem is responsible for performing the actions. However, there's no documentation that I can find! Also, none of the UITextInput delegate methods are called when an operation is performed. I'm almost thinking the solution is private and that I need to ask Apple specifically on how to get access to these features (which I have just done).

更新：

positionFromPosition：inDirection：offset：是用于检测何时按下箭头键的方法。在iOS调用此方法之后，它调用setSelectedText：。你需要解决剩下的管道问题。

positionFromPosition:inDirection:offset: is the method to use to detect when the arrow key is pressed. After iOS has called this method it then calls setSelectedText:. You'll need to work out the rest of the plumbing.

更新2：

我能够回答所有问题。请参阅标记的解决方案以获得答案。

I was able to answer all of the questions I had. Please refer to the marked solution for the answers.

推荐答案

想出来。我已经实现了UIMenuController方法来支持剪切，复制和粘贴。通过实现这些功能和将蓝牙键盘连接到物理设备，您将自动获得基本命令选项（a，c，x，v和朋友）。您需要完全实现UIMenuController UIResponderStandardEditActions。我想要注意的是，在iOS模拟器中它将不触发命令（a，c，x，v和friends）动作。当蓝牙键盘连接到物理设备时，我能够观察到仅的这些功能 - 即使在模拟器中启用了模拟硬件键盘。

Figured it out. I had already implemented the UIMenuController methods to support cut, copy and paste. By implementing these features and connecting a bluetooth keyboard to a physical device you will automatically get the basic command options (a, c, x, v and friends). You need to completely implement UIMenuController UIResponderStandardEditActions. I want to note that in the iOS simulator it will not trigger command (a, c, x, v and friends) actions. I was able to observe these features working only when a bluetooth keyboard was attached to a physical device -- even though "Simulate Hardware Keyboard" had been enabled in the simulator.

关于控制/选项键;当您完全实现UITextInput时，您还将获得使用箭头键，箭头键+控件，箭头键+选项等时的所有移动功能。查看Apple提供的SimpleTextInput示例代码文件，以便更好地了解如何实现此功能。

Regarding control/option keys; when you fully implement UITextInput you will also get all of the movement functionality when using arrow keys, arrow keys + control, arrow keys + option, etc. Look at the SimpleTextInput example code file provided by Apple for a better idea on how to implement this.

话虽如此，您可以不创建自己的键盘组合。如果我想要这些功能，Apple会让我为它创建一张票，我不这样做......我真的不在乎支持他们提供的任何东西。因此，目前无法使用Command + s（保存）等命令。

With that said, you can not create your own keyboard combinations. Apple asked me to create a ticket for it if I wanted those features, which I don't... I really don't care to support anything more than what they have provided. So, commands like Command+s (save), etc. are not currently possible.

一个有趣的小故事; Apple说我想做的事情不可能（使用命令+ c，命令+ v等）与API。我想这表明你对他们的技术专长有何帮助。 非常令人失望。

A fun little story for you; Apple said that what I wanted to do was not possible (using command+c, command+v, etc.) with the API. I guess that shows how you helpful their technical expertise is. Very disappointing.

更新：

自在iOS 7中，Apple已经轻而易举地捕获了任何关键命令，esc等。以下是一个如何捕获各种不同键的示例：

Since iOS 7, Apple has made it trivial to capture any key command, esc, etc. Here is an example of how one could capture a variety of different keys:

return @[[UIKeyCommand keyCommandWithInput:UIKeyInputEscape modifierFlags:0 action:@selector(escapeKeyPressed:)],
         [UIKeyCommand keyCommandWithInput:@"f" modifierFlags:UIKeyModifierCommand action:@selector(commandFindPressed:)],
         [UIKeyCommand keyCommandWithInput:@"s" modifierFlags:UIKeyModifierCommand action:@selector(commandSavePressed:)],
         [UIKeyCommand keyCommandWithInput:@"b" modifierFlags:UIKeyModifierControl action:@selector(controlBKeyPressed:)],
         [UIKeyCommand keyCommandWithInput:@"f" modifierFlags:UIKeyModifierControl action:@selector(controlFKeyPressed:)],
         [UIKeyCommand keyCommandWithInput:@"r" modifierFlags:UIKeyModifierControl action:@selector(controlRKeyPressed:)]
         ];
...

- (void)commandSavePressed:(UIKeyCommand *)keyCommand
{
    [self saveFile];
}

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