Question

I am using the below written method for getting the current selected line number of textView having attributed text. It works fine if last line is not blank. If last line goes blank this method is not giving a proper line number. 

Method : 

    - (NSInteger)getCurrentLineIndex{
        /*
         Get Current Line Inside UITextView
         */
        CGPoint cursorPosition = [self caretRectForPosition:self.selectedTextRange.start].origin;
        return (NSInteger)(cursorPosition.y / self.font.lineHeight);
    }

Is there any other way to get the current line index?


Fixed :  I already had mRangesArray in which each object gave a range of each line. Using those range objects and comparing with the selected range, I was able to fix the problem.

1）获取范围数组 - （无效）分析 { if（self.mRangesArray！= nil）{ [self.mRangesArray removeAllObjects]; } NSString * string = self.text; NSUInteger numberOfLines，index，stringLength = [string length];

    NSMutableArray *ranges = [NSMutableArray new];
    for (index = 0, numberOfLines = 0; index < stringLength; numberOfLines++)
    {
        NSRange range = [string lineRangeForRange:NSMakeRange(index, 0)];
        [ranges addObject:[NSValue valueWithRange:range]];
    }
    if (self.mRangesArray == nil) {
        self.mRangesArray = [[NSMutableArray alloc]init];
    }
    self.mRangesArray = ranges;
}

2）将RangesArray内的范围对象与当前选定的范围进行比较 - （NSInteger）getCurrentLineIndex { / * 此方法将用于获取mRangesArray * / [自我分析];

    /*
     Get Current Line Inside UITextView
     */

    NSRange selectedRange = self.selectedRange;

   __block NSInteger index = [self.mRangesArray count]-1;
    [self.mRangesArray enumerateObjectsUsingBlock:^(id  _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
        NSRange objectRange = [obj rangeValue];
        if (*stop == NO) {
            if (NSLocationInRange(selectedRange.location, objectRange)) {
                index = idx;
                *stop =YES;
                return;
              }
        }
    }];

}

谢谢你们的帮助。干杯：）

Answer 1

编辑：我显然忽略了您当前选择的部分问题。我仍会保留代码，以防有人需要它。

您是否尝试过计算换行符？

let str = "First\nSecond\nThird"
let tok = str.componentsSeparatedByString("\n")
print(tok.count) // Hopefully prints "3"

Answer 2

尝试使用此代码

UIFont * fontNAme = [UIFont boldSystemFontOfSize:13.0]; 
CGSize size = [textView.text fontNAme  constrainedToSize:textView.frame.size  lineBreakMode:UILineBreakModeWordWrap]; 
int lineNumber = size.height / fontNAme .lineHeight;
NSLog(@"line = %d", lineNumber);

如何在UITextView中获取当前选定的行号？

2 个答案: