NSMutableParagraphStyle *paraStyle = [[NSMutableParagraphStyle alloc] init];
paraStyle.lineBreakMode = NSLineBreakByWordWrapping;
paraStyle.alignment = NSTextAlignmentLeft;
paraStyle.lineSpacing = 11; //設置行間距
paraStyle.hyphenationFactor = 1.0;
paraStyle.firstLineHeadIndent = 0.0;
paraStyle.paragraphSpacingBefore = 0.0;
paraStyle.headIndent = 0;
paraStyle.tailIndent = 0;
NSDictionary *dic = @{NSFontAttributeName:font, NSParagraphStyleAttributeName:paraStyle, NSKernAttributeName: 11
};
NSAttributedString *attributeStr = [[NSAttributedString alloc] initWithString:str attributes:dic];
label.attributedText = attributeStr;

一、設置textView的行間距
1.如果只是靜態顯示textView的內容為設置的行間距，執行如下代碼：

// textview 改變字體的行間距
NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
paragraphStyle.lineSpacing = 10;// 字體的行間距

NSDictionary *attributes = @{ 
                             NSFontAttributeName:[UIFont systemFontOfSize:15], 
                             NSParagraphStyleAttributeName:paragraphStyle 
                             }; 
textView.attributedText = [[NSAttributedString alloc] initWithString:@"輸入你的內容" attributes:attributes];

2.如果是想在輸入內容的時候就按照設置的行間距進行動態改變，那就需要將上面代碼放到textView的delegate方法里

-(void)textViewDidChange:(UITextView *)textView

{

//    textview 改變字體的行間距

NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];

paragraphStyle.lineSpacing = 20;// 字體的行間距



NSDictionary *attributes = @{

                             NSFontAttributeName:[UIFont systemFontOfSize:15],

                             NSParagraphStyleAttributeName:paragraphStyle

                             };

textView.attributedText = [[NSAttributedString alloc] initWithString:textView.text attributes:attributes];

}