根据字体大小设置首行缩进的尺寸。一般首行缩进2个字符,字体大的缩进就大一些。
-(void)textViewDidChange:(UITextView *)textView{
NSMutableParagraphStyle * paragraphStyle = [[NSMutableParagraphStyle alloc] init];
paragraphStyle.tailIndent = 0.0f; //行尾缩进
paragraphStyle.lineSpacing = 2.0f; //行间距
paragraphStyle.alignment = NSTextAlignmentLeft; //对齐
paragraphStyle.headIndent = 0.0f; //行首缩进
//参数:(字体大小17号字乘以2,34f即首行空出两个字符)
CGFloat emptylength = self.contentLabel.font.pointSize * 2;
paragraphStyle.firstLineHeadIndent = emptylength; //首行缩进
textView.attributedText = [[NSAttributedString alloc] initWithString:textView.text attributes:@{NSParagraphStyleAttributeName:paragraphStyle}];
}