iOS UILabel文字缩进

使用NSMutableParagraphStyle实现label文字首尾的缩进

    NSMutableParagraphStyle *paraStyle = [[NSMutableParagraphStyle alloc] init];
    paraStyle.alignment = NSTextAlignmentLeft;//对齐
    paraStyle.headIndent = 0.0f;//行首缩进
    //字体大小号字乘以2 即首行空出两个字符
    CGFloat emptylen = 15 * 2;
    paraStyle.firstLineHeadIndent = emptylen;//首行缩进
    paraStyle.tailIndent = 100.0f;//行尾缩进
    paraStyle.lineSpacing = 2.0f;//行间距
    NSAttributedString *attrText = [[NSAttributedString alloc] initWithString:model.descr attributes:@{NSParagraphStyleAttributeName:paraStyle}];
    _introduceLabel.attributedText = attrText;