UITextView lineSpacing 导致段落行之间的光标高度不同 [英] UITextView lineSpacing cause different cursor height between paragraph lines

问题描述

我在 UITextview 中使用 NSMutableParagraphStyle 在每行文本之间添加行空间.

I'm using NSMutableParagraphStyle in my UITextview for adding linespace between each row text.

当我在 textview 中输入内容时，光标高度是正常的.但是当我将光标位置移动到第二行(不是最后一行)的文本时，光标高度越来越大.

When I type something in textview, cursor height is normal. but when I move cursor position to text on the 2nd row (not the last row), cursor height is getting bigger.

我应该怎么做才能使每行文本中的光标高度正常?这是我目前使用的代码:

What should I do to make cursor height normal in every row of the texts? This is code I'm currently using:

NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
paragraphStyle.lineSpacing = 30.;
textView.font = [UIFont fontWithName:@"Helvetica" size:16];
textView.attributedText = [[NSAttributedString alloc] initWithString:@"My Text" attributes:@{NSParagraphStyleAttributeName : paragraphStyle}];

推荐答案

我终于找到了解决我问题的方案.

Finally I found a solution that solved my problem.

可以通过继承 UITextView 的子类，然后覆盖 caretRectForPosition:position 函数来更改光标高度.例如:

Changing the cursor height is possible by subclassing the UITextView, then overriding the caretRectForPosition:position function. For example:

- (CGRect)caretRectForPosition:(UITextPosition *)position {
    CGRect originalRect = [super caretRectForPosition:position];
    originalRect.size.height = 18.0;
    return originalRect;
}

文档链接:https://developer.apple.com/documentation/uikit/uitextinput/1614518-caretrectforposition

参见内特的回答.

对于 Swift 4.x 使用 caretRect(for position: UITextPosition) ->CGRect.

For Swift 4.x use caretRect(for position: UITextPosition) -> CGRect.

import UIKit

class MyTextView: UITextView {

    override func caretRect(for position: UITextPosition) -> CGRect {
        var superRect = super.caretRect(for: position)
        guard let font = self.font else { return superRect }

        // "descender" is expressed as a negative value, 
        // so to add its height you must subtract its value
        superRect.size.height = font.pointSize - font.descender 
        return superRect
    }
}

文档链接:https://developer.apple.com/documentation/uikit/uitextinput/1614518-caretrect

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