iOS 8 中的 UITextView 文本选择和高亮跳转 [英] UITextView text selection and highlight jumping in iOS 8

问题描述

我正在使用 UIMenuItem 和 UIMenuController 将 highlight 功能添加到我的 UITextView，因此用户可以改变所选文本的背景颜色，如下图所示:

I'm using UIMenuItem and UIMenuController to add a highlight feature to my UITextView, so the user can change the background color of the selected text, as shown in the pictures bellow:

• 在 UITextView 中设置文本，用户可以使用 highlight 功能:

• Setected text in UITextView with the highlight feature available to the user:

UITextView">

• 在 UITextView 中突出显示的文本具有新的背景颜色，由用户在点击 突出显示 功能后选择:

• Highlighted text in UITextView with a new background color, chosen by the user after tapping on the highlight feature:

在 iOS 7 中，以下代码工作可以完美地完成此任务:

In iOS 7 the following code is working perfectly to accomplish this task:

- (void)viewDidLoad {

    [super viewDidLoad];

    UIMenuItem *highlightMenuItem = [[UIMenuItem alloc] initWithTitle:@"Highlight" action:@selector(highlight)];
    [[UIMenuController sharedMenuController] setMenuItems:[NSArray arrayWithObject:highlightMenuItem]];
}

- (void)highlight {

    NSRange selectedTextRange = self.textView.selectedRange;

    [attributedString addAttribute:NSBackgroundColorAttributeName
                             value:[UIColor redColor]
                             range:selectedTextRange];

    // iOS 7 fix, NOT working in iOS 8 
    self.textView.scrollEnabled = NO;
    self.textView.attributedText = attributedString;
    self.textView.scrollEnabled = YES;
}

但在 iOS 8 中，文本选择正在跳跃.当我使用 UIMenuItem 和 UIMenuController 中的 highlight 功能时，它也会跳转到另一个 UITextView 偏移量.

But in iOS 8 the text selection is jumping. When I use the highlight feature from the UIMenuItem and UIMenuController it jumps also to another UITextView offset.

如何在 iOS 8 中解决这个问题?

How do I solve this problem in iOS 8?

推荐答案

我最终是这样解决了我的问题，如果其他人有更优雅的解决方案，请告诉我:

I ended up solving my problem like this, and if someone else has a more elegant solution please let me know:

- (void)viewDidLoad {

    [super viewDidLoad];

    UIMenuItem *highlightMenuItem = [[UIMenuItem alloc] initWithTitle:@"Highlight" action:@selector(highlight)];
    [[UIMenuController sharedMenuController] setMenuItems:[NSArray arrayWithObject:highlightMenuItem]];

    float sysVer = [[[UIDevice currentDevice] systemVersion] floatValue];

    if (sysVer >= 8.0) {
        self.textView.layoutManager.allowsNonContiguousLayout = NO;
    } 
}

- (void)highlight {

    NSRange selectedTextRange = self.textView.selectedRange;

    [attributedString addAttribute:NSBackgroundColorAttributeName
                             value:[UIColor redColor]
                             range:selectedTextRange];

    float sysVer = [[[UIDevice currentDevice] systemVersion] floatValue];
    if (sysVer < 8.0) {
        // iOS 7 fix
        self.textView.scrollEnabled = NO;
        self.textView.attributedText = attributedString;
        self.textView.scrollEnabled = YES;
    } else {
        self.textView.attributedText = attributedString;
    }
}

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