在工程根目录建立一个文件夹，然后拖到Xcode， 注意要选蓝色文件夹

        let htmlName = "html_name"
    let htmlType = "html"
    
    private func loadHtml() {
        let filePath = Bundle.main.path(forResource: htmlName, ofType: "html")!
        do {
            let html = try String(contentsOfFile: filePath, encoding: String.Encoding.utf8)
            webView.loadHTMLString(html, baseURL: Bundle.main.resourceURL)
        } catch {
            
        }
    }