UITextView 更改 selectRange 总是崩溃

Posted 2023-02-24

【中文标题】UITextView 更改 selectRange 总是崩溃

【英文标题】：UITextView change selectRange always crash

【发布时间】：2016-09-22 09:38:31

【问题描述】：

当用户单击textView中的段落时，我想将光标更改为linebreak，但是当我更改selectionRange时总是失败。 我知道原因，但我必须更改func: textViewDidChangeSelection:(UITextView*)textView中的selectedRange

如何更改 selectedRange？

这是代码

-(void)textViewDidChangeSelection:(UITextView *)textView

//    paragLocations:   it contain all "\n" locations
NSArray* paragLocations = [self ParagraphLocationsWithText:textView Pattern:translatePragraphLinebreak];

//     location :According to user selection,The nearest "\n" location
NSUInteger nearestLocation = [self ClickParagraphEndBreakLoctionWithSelectLocation:textView.selectedRange.location withParagLocations:paragLocations];
//Then
//1. here I change the textView.selectedRange
textView.selectedRange = NSMakeRange(nearestLocation, 0);
//2. here I change the cursorPosition
CGFloat cursorPosition = [self caretRectForPosition:textView.selectedTextRange.start].origin.y;
[textView setContentOffset:CGPointMake(0, cursorPosition) animated:YES];
// but In step 1  ,It changed textView.selectedRange,So this func will do it again,and then again,until the nearestLocation became the paragLocations.lastObject.
/*
        so the question is how to break this Infinite loop ?  
        should I change selectedRange In this func?
        I want to changed the selectedRange base on User select In textview
 */

对不起我的英语不好。

【问题讨论】：

是“更改 selectionRange 总是失败”还是 selectedRange ..？

我编辑问题解释清楚

【参考方案1】：

您可以尝试以下代码，它对我来说很好。

- (void)textViewDidChangeSelection:(UITextView *)textView 

       UITextRange *selectRange = [textView selectedTextRange];
       NSString *selectedText = [textView textInRange:selectRange];
    

【讨论】：

我只是想改变 func 中的 selectRange ，而不是这个