是否可以让一个由多个 \n
分隔的行组成的 UILabel
的行的宽度 > 标签宽度被截断而不换行?
假设我有一些像下面这样的文本:
- 这是一个非常长的第一行文本,水平放置太长
- 短线
- 另一条短线
我希望它像这样出现在我的 UILabel
中:
1. This is a really long first line of text... 2. Short line 3. Another short line
但是发生的事情是我得到这个:
1. This is a really long first line of text that is too long to fit horizontally 2. Short line...
第三行被截断了。我已将行数设置为 3
,但它仍在换行第一行。我在标签上将换行符属性设置为什么似乎无关紧要——它总是换行第一行。有什么办法可以防止完全缠绕在标签上吗?
最佳答案
我认为这对于您可以应用于标签的任何设置都是不可能的。一种方法是将字符串分成单独的行,截断任何需要它的行,使其(加上省略号)适合一行,然后将字符串放回原处并换行。像这样的东西应该适用于任意数量的行,
@interface ViewController ()
@property (weak, nonatomic) IBOutlet UILabel *label;
@property (nonatomic) CGFloat ellipsisWidth;
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
NSString *text = @"This is a really long first line of text that is too long to fit horizontally\nShort line\nAnother short line";
NSString *ellipsis = @"...";
self.ellipsisWidth = [ellipsis sizeWithAttributes:@{NSFontAttributeName:self.label.font}].width;
__block NSMutableString *truncatedString = [@"" mutableCopy];
[text enumerateLinesUsingBlock:^(NSString *line, BOOL *stop) {
[truncatedString appendFormat:@"%@\n", [self oneLineOfString:line withFont:self.label.font]];
}];
NSString *finalString = [truncatedString stringByTrimmingCharactersInSet:[NSCharacterSet newlineCharacterSet]];
self.label.numberOfLines = 0;
self.label.text = finalString;
}
-(NSString *)oneLineOfString:(NSString *) aLine withFont:(UIFont *) font {
__block NSString *singleLine = nil;
__block NSString *lastFragment;
[aLine enumerateSubstringsInRange:NSMakeRange(0, aLine.length) options:NSStringEnumerationByWords usingBlock:^(NSString *substring, NSRange substringRange, NSRange enclosingRange, BOOL *stop) {
NSString *textFragment = [aLine substringToIndex:(substringRange.location + substringRange.length)];
CGRect textRect = [textFragment boundingRectWithSize:CGSizeMake(CGFLOAT_MAX ,CGFLOAT_MAX) options:NSStringDrawingUsesLineFragmentOrigin attributes:@{NSFontAttributeName:font} context:nil];
if (textRect.size.width >= self.label.bounds.size.width - self.ellipsisWidth) {
singleLine = [lastFragment stringByAppendingString:@"..."];
*stop = YES;
}
lastFragment = textFragment;
}];
if (!singleLine) singleLine = aLine; // it doesn't need to be truncated, so return the passed in line
return singleLine;
}
如果你想按字符截断而不是按单词截断,你可以将 NSStringEnumerationByComposedCharacterSequences 而不是 NSStringEnumerationByWords 传递给 options 参数 enumerateSubstringsInRange:options:usingBlock:.
当然,你可以用简单的方法来做;将 3 个标签堆叠在一起,并给每个标签一行你的文字 :)
关于ios - 没有自动换行的多行 UILabel?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/26394249/