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];  
paraStyle.alignment = NSTextAlignmentLeft;  //對齊  
paraStyle.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;  
paraStyle.firstLineHeadIndent = emptylen;//首行縮排  
paraStyle.tailIndent = 0.0f;//行尾縮排  
paraStyle.lineSpacing = 2.0f;//行間距  
NSAttributedString *attrText = [[NSAttributedString alloc] initWithString:test attributes:@{NSParagraphStyleAttributeName:paraStyle}];  
self.contentLabel.attributedText = attrText;