电商网站的二级菜单怎么做网上电商平台开发
前文介绍如何使用图片生成pdf,这里介绍如何使用文本生成pdf
使用mupdf生成
mupdf生成的pdf略大,字体可以自定义.
生成的代码不复杂,也有好几种,以story的方式生成为例
fun createPdfFromText(sourcePath: String, destPath: String): Boolean {val text = EncodingDetect.readFile(sourcePath)val mediabox = Rect(0f, 0f, 500f, 707f) //A2val margin = 10fvar writer = DocumentWriter(destPath, "PDF", "")var snark = "<!DOCTYPE html>" +"<style>" +"#body { font-family: \"Droid Sans\", sans-serif; }" +"</style>" +"<body>" +text +"</body></html>"val story = Story(snark, "", 12f)var more: Booleando {val filled = Rect()val where = Rect(mediabox.x0 + margin,mediabox.y0 + margin,mediabox.x1 - margin,mediabox.y1 - margin)val dev: Device = writer.beginPage(mediabox)more = story.place(where, filled)story.draw(dev, Matrix.Identity())writer.endPage()} while (more)writer.close()writer.destroy()story.destroy()return true}文档的读取,对于中文,可能会涉及到编码的处理.
先定义mediabox,就是纸张大小,这里是a2
然后用html生成story,最后写入就完成了
如果要自定义样式,颜色这些,api要去查如何使用.并不那么方便.
使用系统sdk生成
系统sdk是基于福昕的代码.但生成时可以使用view来设置样式,然后生成页面.样式比较容易控制,毕竟view长什么样是容易修改的.
读取文本是一样的.
val pdfDocument = PdfDocument()val pageWidth = PDF_PAGE_WIDTH.toInt()val pageHeight = PDF_PAGE_HEIGHT.toInt()val contentView =LayoutInflater.from(context).inflate(R.layout.pdf_content, parent, false) as TextViewcontentView.text = contentval measureWidth = View.MeasureSpec.makeMeasureSpec(pageWidth, View.MeasureSpec.EXACTLY)val measuredHeight = View.MeasureSpec.makeMeasureSpec(pageHeight, View.MeasureSpec.EXACTLY)contentView.measure(measureWidth, measuredHeight)contentView.layout(0, 0, pageWidth, pageHeight)建立文档对象,然后加载布局
val lineCount = contentView.lineCountvar lineHeight = contentView.lineHeightif (contentView.lineSpacingMultiplier > 0) {lineHeight = (lineHeight * contentView.lineSpacingMultiplier).toInt()}val layout = contentView.layoutvar start = 0var end: Intvar pageH = 0val paddingTopAndBottom: Int = Utils.dipToPixel(context, 40f)设置边距40dp,读取行间距与行数.
因为设置了内容后,由textview自己就能计算出这些,然后根据这些信息,计算我们一页的高宽可以分成几页,然后每一页再用一个布局去生成就行了.
while (i < lineCount) {end = layout.getLineEnd(i)val line = content.substring(start, end) //指定行的内容start = endsb.append(line)pageH += lineHeightif (pageH >= pageHeight - paddingTopAndBottom) {Log.d("TextView",String.format("============page line:%s,lh:%s,ph:%s==========",i,lineHeight,pageHeight))createTxtPage(context,parent,pdfDocument,pageWidth,pageHeight,i + 1,sb.toString())pageH = 0sb.setLength(0)}i++}if (sb.length > 0) {Log.d("TextView", "last line ===")createTxtPage(context, parent, pdfDocument, pageWidth, pageHeight, i, sb.toString())}这就是计算的过程,最后要再处理剩下的部分.
对于每一页的显示字符数处理完,接着就是对这些生成页面
private fun createTxtPage(context: Context?,parent: ViewGroup?,pdfDocument: PdfDocument,pageWidth: Int,pageHeight: Int,pageNo: Int,content: String?) {val contentView =LayoutInflater.from(context).inflate(R.layout.pdf_content, parent, false) as TextViewcontentView.text = contentval pageInfo: PdfDocument.PageInfo =PdfDocument.PageInfo.Builder(pageWidth, pageHeight, pageNo).create()val page: PdfDocument.Page = pdfDocument.startPage(pageInfo)val pageCanvas: Canvas = page.getCanvas()val measureWidth = View.MeasureSpec.makeMeasureSpec(pageWidth, View.MeasureSpec.EXACTLY)val measuredHeight = View.MeasureSpec.makeMeasureSpec(pageHeight, View.MeasureSpec.EXACTLY)contentView.measure(measureWidth, measuredHeight)contentView.layout(0, 0, pageWidth, pageHeight)contentView.draw(pageCanvas)// finish the pagepdfDocument.finishPage(page)}页面同样用之前的布局,这样保持是一致的,否则高宽计算就不对了.这里因为不需要显示,所以我们要调用measure与layout再draw画出来
保存就简单了
private fun savePdf(path: String?, document: PdfDocument): Boolean {val outputStream = FileOutputStream(path)try {document.writeTo(outputStream)return true} catch (e: IOException) {e.printStackTrace()} finally {document.close()}return false}