iOS 计算NSString宽高与计算NSAttributedString的宽高
iOS 计算NSString宽高与计算NSAttributedString的宽高
GuangdongQi
发布于 2018-05-24 17:49:12
发布于 2018-05-24 17:49:12
开篇
项目有一个客服反馈功能，用到的是聊天列表的形式，这就免不了计算字符串的宽高，由于要给字符串加间距，没办法，只能用 NSAttributedString 所以要计算NSAttributedString的长宽
计算NSString宽高
计算NSString宽高很简单，代码如下：
//返回字符串所占用的尺寸.
- (CGSize)sizeWithFont:(UIFont *)font maxSize:(CGSize)maxSize
{
NSDictionary *attrs = @{NSFontAttributeName : font};
return [self boundingRectWithSize:maxSize options:NSStringDrawingUsesLineFragmentOrigin attributes:attrs context:nil].size;
}参数解读
font 是当前字符串的字体（包含大小信息） maxSize 是一个最大的距离：如我最大的宽度只让他为200，高度不限，则传入：
CGSizeMake(200 , CGFLOAT_MAX)计算NSAttributedString宽高
先查看系统API：
Paste_Image.png
代码如下：
- (CGRect)boundsWithFontSize:(CGFloat)fontSize text:(NSString *)text needWidth:(CGFloat)needWidth lineSpacing:(CGFloat )lineSpacing
{
NSMutableAttributedString *attributeString = [[NSMutableAttributedString alloc] initWithString:text];
NSMutableParagraphStyle *style = [[NSMutableParagraphStyle alloc] init];
style.lineSpacing = lineSpacing;
UIFont *font = Font_Light(fontSize);
[attributeString addAttribute:NSParagraphStyleAttributeName value:style range:NSMakeRange(0, text.length)];
[attributeString addAttribute:NSFontAttributeName value:font range:NSMakeRange(0, text.length)];
NSStringDrawingOptions options = NSStringDrawingUsesLineFragmentOrigin | NSStringDrawingUsesFontLeading;
CGRect rect = [attributeString boundingRectWithSize:CGSizeMake(needWidth, CGFLOAT_MAX) options:options context:nil];
return rect;
}参数解读
fontSize :是当前字符串的字体（包含大小信息） text：将要计算的�字符串 needWidth：将要计算的最大宽度 lineSpacing：行间距大小
当然关于 NSAttributedString 的设置还有很多，不一一列举了，提供一个同事封装好的留下以后用
调整行间距
//调整行间距
+ (NSMutableAttributedString *)atttibutedStringForString:(NSString *)string LineSpace:(CGFloat)lineSpace {
NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithString:string];
NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
[paragraphStyle setLineSpacing:lineSpace];
paragraphStyle.lineBreakMode = NSLineBreakByTruncatingTail;
[attributedString addAttribute:NSParagraphStyleAttributeName value:paragraphStyle range:NSMakeRange(0, [string length])];
return attributedString;
}设置属性文字
+ (NSMutableAttributedString *)attributedStringForString:(NSString *)string attributeds:(NSDictionary *)attributeds hasPrefix:(NSString *)hasPrefix hasSuffix:(NSString *)hasSuffix {
if (string.length == 0) {
return nil;
}
if (hasSuffix.length ==0) {
hasSuffix = @"";
}
if (hasPrefix.length == 0) {
hasPrefix = @"";
}
NSString *str = [NSString stringWithFormat:@"%@%@%@",hasPrefix,string,hasSuffix];
NSRange range = [str rangeOfString:string];
NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc]initWithString:str];
[attributedString addAttributes:attributeds range:range];
if ([attributeds objectForKey:@"NSParagraphStyle"]) {
NSMutableParagraphStyle * paragraphStyle = [attributeds objectForKey:@"NSParagraphStyle"];
[attributedString addAttribute:NSParagraphStyleAttributeName value:paragraphStyle range:NSMakeRange(0, string.length)];
}
return attributedString;
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原始发表：2017.04.19 ，如有侵权请联系 cloudcommunity@tencent.com 删除
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