ios首行缩进

  NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc]init];
        paragraphStyle.firstLineHeadIndent = 15; // 首行缩进
        paragraphStyle.alignment = NSTextAlignmentJustified;
        NSMutableDictionary *attributes = [@{ NSFontAttributeName:[UIFont systemFontOfSize:14], NSParagraphStyleAttributeName:paragraphStyle, NSForegroundColorAttributeName:[UIColor colorWithHexString:@"#8F92A1"]
                                              }mutableCopy];
        self.contentTF.placeholderAttributedText = [[NSAttributedString alloc]initWithString: @"请输入意见内容，越详细越好" attributes:attributes];