UITextView添加文本点击事件，屏蔽其他事件问题记录

UITextView 给某段文字添加点击事件非常方便，使用富文本添加NSLinkAttributeName属性即可。但是UITextView本身带有许多编辑事件，导致在触发NSLinkAttributeName事件时难免触发一些我们不需要的事件，影响用户体验，即使设置textView.editable = NO;关闭textView的编辑事件也不能完全屏蔽。
为了解决这一问题，将UITextView上的所有手势遍历一遍，发现有22中手势。

for (UIGestureRecognizer *ges in text.gestureRecognizers) {
        NSLog(@"textView ges description : %@", ges.description);    
}
    

结果:

2020-08-14 10:13:57.238155+0800 workspace[19737:376980] textView ges description : ; target= <(action=onStateUpdate:, target=)>>
2020-08-14 10:13:57.238509+0800 workspace[19737:376980] textView ges description : ; target= <(action=tapAndAHalf:, target=)>>
2020-08-14 10:13:57.238949+0800 workspace[19737:376980] textView ges description : ; target= <(action=loupeGesture:, target=)>; numberOfTapsRequired = 0; minimumPressDuration = 0.5>
2020-08-14 10:13:57.239315+0800 workspace[19737:376980] textView ges description : ; target= <(action=linkTapped:, target=<_UITextMenuLinkInteraction 0x6000012b08c0>)>>
2020-08-14 10:13:57.239669+0800 workspace[19737:376980] textView ges description : ; target= <(action=delayed:, target=)>>
2020-08-14 10:13:57.268294+0800 workspace[19737:376980] textView ges description : ; target= <(action=handlePan:, target=)>>
2020-08-14 10:13:57.268759+0800 workspace[19737:376980] textView ges description : ; target= <(action=_handleKnobLongPressGesture:, target=)>; numberOfTapsRequired = 0; minimumPressDuration = 0.1>
2020-08-14 10:13:57.268935+0800 workspace[19737:376980] textView ges description : ; target= <(action=_handleKnobLongPressGesture:, target=)>; numberOfTapsRequired = 0>
2020-08-14 10:13:57.269288+0800 workspace[19737:376980] textView ges description : ; target= <(action=_handleKnobHoverGesture:, target=)>>
2020-08-14 10:13:57.269637+0800 workspace[19737:376980] textView ges description : <_UIDragAutoScrollGestureRecognizer: 0x600001caf0c0; state = Possible; cancelsTouchesInView = NO; delaysTouchesEnded = NO; view = ; target= <(action=_handleAutoScroll:, target=)>>
2020-08-14 10:13:57.269956+0800 workspace[19737:376980] textView ges description : <_UIDragAddItemsGesture: 0x7fa031f14e10 (dragAddingItems); state = Possible; delaysTouchesBegan = YES; view = >
2020-08-14 10:13:57.271577+0800 workspace[19737:376980] textView ges description : <_UIDragLiftGestureRecognizer: 0x7fa031f2a860 (dragInitiation); state = Possible; cancelsTouchesInView = NO; view = ; target= <(action=_dragInitiationGestureStateChanged:, target=<_UIDragInteractionLongPressDriver 0x6000011b5440>)>; numberOfTapsRequired = 0; minimumPressDuration = 0.325>
2020-08-14 10:13:57.271901+0800 workspace[19737:376980] textView ges description : <_UIRelationshipGestureRecognizer: 0x600001acea00 (dragExclusionRelationships); state = Possible; view = >
2020-08-14 10:13:57.272043+0800 workspace[19737:376980] textView ges description : <_UIRelationshipGestureRecognizer: 0x600001ace920 (dragFailureRelationships); state = Possible; view = >
2020-08-14 10:13:57.272365+0800 workspace[19737:376980] textView ges description : <_UIDragLiftPointerGestureRecognizer: 0x7fa031f2ae00 (dragInitiation); state = Possible; cancelsTouchesInView = NO; view = ; target= <(action=_dragInitiationGestureStateChanged:, target=<_UIDragInteractionLongPressDriver 0x6000011b55f0>)>; numberOfTapsRequired = 0; minimumPressDuration = 0.15>
2020-08-14 10:13:57.272552+0800 workspace[19737:376980] textView ges description : <_UIRelationshipGestureRecognizer: 0x600001acef40 (dragExclusionRelationships); state = Possible; view = >
2020-08-14 10:13:57.272702+0800 workspace[19737:376980] textView ges description : <_UIRelationshipGestureRecognizer: 0x600001acee60 (dragFailureRelationships); state = Possible; view = >
2020-08-14 10:13:57.273017+0800 workspace[19737:376980] textView ges description : <_UISecondaryClickDriverGestureRecognizer: 0x600001afe060; state = Possible; view = ; target= <(action=_handleGestureRecognizer:, target=<_UISecondaryClickClickInteractionDriver 0x6000036cd500>)>>
2020-08-14 10:13:57.273402+0800 workspace[19737:376980] textView ges description : <_UITouchDurationObservingGestureRecognizer: 0x7fa031d2c310 (com.apple.UIKit.longPressClickDriverPrimary); state = Possible; cancelsTouchesInView = NO; view = ; target= <(action=_handleGestureRecognizer:, target=<_UILongPressTimeoutClickInteractionDriver 0x600000088c80>)>>
2020-08-14 10:13:57.273564+0800 workspace[19737:376980] textView ges description : <_UITouchDurationObservingGestureRecognizer: 0x7fa031d2c640 (com.apple.UIKit.longPressClickDriverPrimary); state = Possible; cancelsTouchesInView = NO; view = ; target= <(action=_handleGestureRecognizer:, target=<_UILongPressTimeoutClickInteractionDriver 0x600000088cd0>)>>
2020-08-14 10:13:57.275039+0800 workspace[19737:376980] textView ges description : <_UIRelationshipGestureRecognizer: 0x600001a34700 (com.apple.UIKit.clickPresentationExclusion); state = Possible; view = >
2020-08-14 10:13:57.275212+0800 workspace[19737:376980] textView ges description : <_UIRelationshipGestureRecognizer: 0x600001a347e0 (com.apple.UIKit.clickPresentationFailure); state = Possible; view = >

其中与NSLinkAttributeName相关的linkTapped事件是一个UITapGestureRecognizer点击事件，有且仅有一个，那么大胆尝试一下，将所有除UITapGestureRecognizer外的手势事件全部删除:

for (UIGestureRecognizer *ges in textView.gestureRecognizers) {
            if (![ges isMemberOfClass:[UITapGestureRecognizer class]]) {
                [textView removeGestureRecognizer:ges];
            }
        }

删除后发现确实只剩下了自己添加的NSLinkAttributeName点击事件会响应，其他不相关事件的始终与完美屏蔽。

UITextView文本显示边距问题

1.去除文本上下边距
textView.textContainerInset = UIEdgeInsetsZero;
2.出去文本左右边距（将内容缩进设置为0）
textView.textContainer.lineFragmentPadding = 0;
使用上述方法去除文本左右边距后，UITextView选择功能出现问题，左边选择控件无法移动问题。
解决办法：
textView.textContainer.lineFragmentPadding 默认值为5，即文本默认左右边距为5，可通过textView.contentInset与textView.textContainer.lineFragmentPadding计算设置文本左右边距。