NSString *_test  =  @"首行縮排根據字型大小自動調整 間隔可自定根據需求隨意改變。。。。。。。" ;
    NSMutableParagraphStyle *paraStyle01 = [[NSMutableParagraphStyle alloc] init];
    paraStyle01.alignment = NSTextAlignmentLeft;  //對齊
    paraStyle01.headIndent = 0.0f;//行首縮排
    //引數：（字型大小17號字乘以2，34f即首行空出兩個字元）
    CGFloat emptylen = self.contentLabel.font.pointSize * 2;
    paraStyle01.firstLineHeadIndent = emptylen;//首行縮排
    paraStyle01.tailIndent = 0.0f;//行尾縮排
    paraStyle01.lineSpacing = 2.0f;//行間距
    
    NSAttributedString *attrText = [[NSAttributedString alloc] initWithString:_test attributes:@{NSParagraphStyleAttributeName:paraStyle01}];
    
    self.contentLabel.attributedText = attrText;