Question

我在UILabel中有一些文字。我想在字符串变量中获取第一个标签的文本。

例如：

label.text = @"You make an object by creating an instance of a particular class. You do this by allocating the object and initializing it with acceptable default values. When you allocate an object, you set aside enough memory for the object and set all instance variables to zero. Initialization sets an object’s initial state—that is, its instance variables and properties—to reasonable values and then returns the object. The purpose of initialization is to return a usable object. You need to both allocate and initialize an object to be able to use it.";

现在我想获取UILabel中第一行的文字。

Answer 1

1.添加CoreText.framework。 2.导入#import CoreText / CoreText.h＆gt;。然后使用以下方法 -

-(NSArray *)getLinesArrayOfStringInLabel:(UILabel *)label
{
    NSString *text = [label text];
    UIFont   *font = [label font];
    CGRect    rect = [label frame];

    CTFontRef myFont = CTFontCreateWithName(( CFStringRef)([font fontName]), [font pointSize], NULL);
    NSMutableAttributedString *attStr = [[NSMutableAttributedString alloc] initWithString:text];
    [attStr addAttribute:(NSString *)kCTFontAttributeName value:( id)myFont range:NSMakeRange(0, attStr.length)];

    CFRelease(myFont);

    CTFramesetterRef frameSetter = CTFramesetterCreateWithAttributedString(( CFAttributedStringRef)attStr);

    CGMutablePathRef path = CGPathCreateMutable();
    CGPathAddRect(path, NULL, CGRectMake(0,0,rect.size.width,100000));

    CTFrameRef frame = CTFramesetterCreateFrame(frameSetter, CFRangeMake(0, 0), path, NULL);

    NSArray *lines = ( NSArray *)CTFrameGetLines(frame);

    NSMutableArray *linesArray = [[NSMutableArray alloc]init];

    for (id line in lines)
    {
        CTLineRef lineRef = ( CTLineRef )line;
        CFRange lineRange = CTLineGetStringRange(lineRef);
        NSRange range = NSMakeRange(lineRange.location, lineRange.length);

        NSString *lineString = [text substringWithRange:range];

        CFAttributedStringSetAttribute((CFMutableAttributedStringRef)attStr, lineRange, kCTKernAttributeName, (CFTypeRef)([NSNumber numberWithFloat:0.0]));
        CFAttributedStringSetAttribute((CFMutableAttributedStringRef)attStr, lineRange, kCTKernAttributeName, (CFTypeRef)([NSNumber numberWithInt:0.0]));

        //NSLog(@"''''''''''''''''''%@",lineString);
        [linesArray addObject:lineString];

    }
    [attStr release];

    CGPathRelease(path);
    CFRelease( frame );
    CFRelease(frameSetter);


    return (NSArray *)linesArray;
}

我从以下网址找到了这个答案 - How to get text from nth line of UILabel?

NSString *firstLineString = [[self getLinesArrayOfStringInLabel:yourLabel] objectAtIndex:0];

Answer 2

NSString *text = label.text;

//remove any leading or trailing whitespace or line breaks
text = [text stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];

//find the the range of the first occuring line break, if any.
NSRange range = [text rangeOfString:@"\n"];

//if there is a line break, get a substring up to that line break
if(range.location != NSNotFound)
    text = [text substringToIndex:range.location];

Answer 3

这可能对您有所帮助

var array = string.componentsSeparatedByString("\r")

这会将字符串与新行分开，您可以在数组中获得直线文本。

在UILabel中获取第一行的字符串

3 个答案: