2019-01-15 Swift UIScrollView转换为

直接上代码，见注释说明

        // 初始化可变data类型变量接收scrollview转换的数据        
        let pdfData:NSMutableData = NSMutableData.init()
        // 展开画布并开始转换
        UIGraphicsBeginPDFContextToData(pdfData, CGRect(x:0,y:0, width:scrollView.contentSize.width, height:scrollView.contentSize.height), nil) 
        // 展开PDF页面
        UIGraphicsBeginPDFPageWithInfo(CGRect(x:0, y:0,width: scrollView.contentSize.width,height:scrollView.contentSize.height), nil)
        // 获取当前上下文
        let pdfContext = UIGraphicsGetCurrentContext()
        let originSize = scrollView.frame
        var newSize = originSize
        newSize.size = scrollView.contentSize
        scrollView.frame = newSize
        // 将scrollview数据渲染到上下文
        scrollView.layer.render(in: pdfContext!)
        scrollView.frame = originSize
        // 停止转换/关闭画布
        UIGraphicsEndPDFContext()
        var filePath = NSSearchPathForDirectoriesInDomains(FileManager.SearchPathDirectory.documentDirectory, FileManager.SearchPathDomainMask.userDomainMask, true).first
        filePath = filePath!+"/test.pdf"
        // 写入本地PDF文件
        pdfData.write(toFile: filePath!, atomically: true)