将 UITextView 滚动到特定文本 [英] Scroll UITextView to specific text

问题描述

我有一个带有大文本的uitextview，上面有一个搜索字段.搜索任何内容，我都希望 uitextview 滚动到该特定文本并突出显示.而且我需要确保 uitextview 以这样一种方式滚动，即搜索到的文本保留在第一行

i have a uitextview with large texts and above i have a search field. Anything searched, i would love the uitextview to scroll to that specific text and hightlight. And i need to make sure that the uitextview scrolls in such a way that the searched text stays in the first line

我用带有一些属性的属性文本填充了文本视图.我尝试的是在目标文本之前获取文本，并尝试获取它的大小，添加我在开始时在 textview 文本上添加的确切属性.

I populated the textview with attributed text with some attributes. What i tried is get the text before the target text and tried to get the size of it adding the exact attributes i added on textview text at the beginning.

使用该高度创建一个 CGPoint 并设置 uitextview 的 contentOffset.但是 textview 在目标文本附近没有滚动.也许我的方法是错误的，因为我在设置属性时没有 textview 的宽度

made a CGPoint using that height and set the contentOffset of the uitextview. But the textview scrolled no where near the target text. Maybe my approach is wrong as i dont have the width of the textview when setting attributes

我的代码是:

func goToBla() {
        if let string = ayatTextView.text {

            if let range = string.range(of: tazweedAyahas[8].text) {
                let firstPart = string[string.startIndex..<range.lowerBound]
                print("before \(tazweedAyahas[5].text) : ")
                print(firstPart)


                if let otherStr = firstPart as? NSString {
                    let paragraphStyle = NSMutableParagraphStyle()
                    paragraphStyle.alignment = .center

                    let size = otherStr.size(withAttributes: [NSAttributedStringKey.paragraphStyle: paragraphStyle,
                                                   NSAttributedStringKey.font: UIFont(name: "me_quran", size: 30)
                        ])

                    let point = CGPoint(x: 0, y: size.height)
                    ayatTextView.setContentOffset(point, animated: true)
                }


            }
        }


    }

推荐答案

您的方法比它需要的要复杂得多.使用UITextView的scrollRangeToVisible方法.

Your approach is much more complicated than it needs to be. Use the scrollRangeToVisible method of UITextView.

func goToBla() {
    if let string = ayatTextView.text, let range = string.localizedStandardRange(of: tazweedAyahas[8].text) {
        let viewRange = NSRange(range, in: string)
        ayatTextView.selectedRange = viewRange // optional
        ayatTextView.scrollRangeToVisible(viewRange)
    }
}

注意以下几点:

1. 如果您想忽略变音符号和大小写，并且需要其他特定于区域设置的搜索功能，请在搜索时使用 localizedStandardRange.
2. 如果您希望选择匹配的文本，请调用 selectedRange.

如果您想在顶部获取所选范围，请尝试这样的操作，而不是调用 scrollRangeToVisible:

If you want to get the selected range at the top, try something like this instead of calling scrollRangeToVisible:

let rect = ayatTextView.layoutManager.boundingRect(forGlyphRange: viewRange, in: ayatTextView.textContainer)
ayatTextView.contentOffset = CGPoint(x: 0, y: rect.origin.y)

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