swift实现简单的富文本

效果图：

image

//实现富文本  
        var string:NSMutableAttributedString  
        string = NSMutableAttributedString(string:"北京")  
          
        //进行图文混排  
        var textAttachment:NSTextAttachment  
        textAttachment = NSTextAttachment()  
        textAttachment.image =UIImage(named:"f_flagdown02@2x")  
        textAttachment.bounds =CGRectMake(0,0,11,8);  
        var textAttachmentString:NSAttributedString  
        textAttachmentString = NSAttributedString(attachment: textAttachment)  
//在城市名称后插入图片  
        string.insertAttributedString(textAttachmentString, atIndex: string.length)  
          
        //自定义导航左侧按钮  
        let btn =UIButton.init(type:UIButtonType.RoundedRect)  
        btn.frame =CGRectMake(0,0,70,30);  
        btn.backgroundColor =UIColor.redColor()  
        btn.addTarget(self, action:#selector(navBtnClick), forControlEvents: UIControlEvents.TouchUpInside)  
        let lbText:UILabel  
        lbText = UILabel()  
        lbText.frame =CGRectMake(0,0, btn.frame.size.width+10, btn.frame.size.height)  
        lbText.attributedText = string  
        lbText.textColor =UIColor.whiteColor()  
        lbText.font =UIFont.systemFontOfSize(13)  
        btn.addSubview(lbText)  
        btn.backgroundColor =UIColor.clearColor()  
        self.navigationItem.leftBarButtonItem =UIBarButtonItem.init(customView: btn)