iOS ObjectiveC：支持从右到左
iOS ObjectiveC: Support Right To Left
为了在我的应用中支持从右到左，我使用了以下说明：
[[UIView appearance] setSemanticContentAttribute:UISemanticContentAttributeForceRightToLeft];
[[UIStackView appearance] setSemanticContentAttribute:UISemanticContentAttributeForceRightToLeft];
[UITextView appearance].textAlignment = NSTextAlignmentRight;
但是我有很多问题：
- 如果我需要在当前视图中应用新对齐方式，我不明白如何刷新 UI。
- 在 collection 视图中，即使我使用：
对齐也不会改变
[[UICollectionView appearance] setSemanticContentAttribute:UISemanticContentAttributeForceRightToLeft];
所以我决定使用：
self.sectionsCollectionView.transform = CGAffineTransformMakeScale(-1, 1);
和：
cell.transform = CGAffineTransformMakeScale(-1, 1);
它可以工作，但是如果我按下另一个视图并在我弹出到带有 collection 视图的视图后，它会再次向左对齐，直到我进入 header 部分，之后点击它到右边。
根据 Apple 的文档，
By default, text alignment in iOS is natural; in OS X, it’s left.
Using natural text alignment aligns text on the left in a
left-to-right language, and automatically mirrors the alignment for
right-to-left languages. For example, if you set the alignment of an
NSMutableParagraphStyle object using the setAlignment: method, pass
NSNaturalTextAlignment as the parameter.
[[(NSMutableParagraphStyle *)paraStyle setAlignment:NSNaturalTextAlignment];
However, if you want to align a control to the right in a
left-to-right language (and to the left in a right-to-left language),
get the layout direction, as described in Getting the Layout
Direction, and set the alignment to NSLeftTextAlignment for a
right-to-left language.
为了在我的应用中支持从右到左，我使用了以下说明：
[[UIView appearance] setSemanticContentAttribute:UISemanticContentAttributeForceRightToLeft];
[[UIStackView appearance] setSemanticContentAttribute:UISemanticContentAttributeForceRightToLeft];
[UITextView appearance].textAlignment = NSTextAlignmentRight;
但是我有很多问题： - 如果我需要在当前视图中应用新对齐方式，我不明白如何刷新 UI。 - 在 collection 视图中，即使我使用：
对齐也不会改变[[UICollectionView appearance] setSemanticContentAttribute:UISemanticContentAttributeForceRightToLeft];
所以我决定使用：
self.sectionsCollectionView.transform = CGAffineTransformMakeScale(-1, 1);
和：
cell.transform = CGAffineTransformMakeScale(-1, 1);
它可以工作，但是如果我按下另一个视图并在我弹出到带有 collection 视图的视图后，它会再次向左对齐，直到我进入 header 部分，之后点击它到右边。
根据 Apple 的文档，
By default, text alignment in iOS is natural; in OS X, it’s left. Using natural text alignment aligns text on the left in a left-to-right language, and automatically mirrors the alignment for right-to-left languages. For example, if you set the alignment of an
NSMutableParagraphStyleobject using the setAlignment: method, passNSNaturalTextAlignmentas the parameter.
[[(NSMutableParagraphStyle *)paraStyle setAlignment:NSNaturalTextAlignment];
However, if you want to align a control to the right in a left-to-right language (and to the left in a right-to-left language), get the layout direction, as described in Getting the Layout Direction, and set the alignment to
NSLeftTextAlignmentfor a right-to-left language.