使用 Android 中来自网络 URL 的图像从视图生成 PDF 文件

Question

我正在使用本机 PDF 库生成 PDF 文件 (android.graphics.pdf.PdfDocument)

文档应该包含一个 header 静态 imageView、一些文本视图和一个带有一堆图像的 RecyclerView，

除了 recyclerview 之外的所有内容都正确显示，

recyclerview 正在使用 Glide 库加载图像，但它们既未加载也未显示，我尝试 pre-fetching 使用该库，但它也没有任何作用，

这是创建 pdf 的代码

    public File createPDF(PostDB postDB) {
    int addition = 0;
    String postDBContent = postDB.getContent();
    if (postDBContent != null) {
        int estimatedLineCount = postDBContent.length() / 43;
        String[] lines = postDBContent.split("\r\n|\r|\n");
        estimatedLineCount += lines.length;
        addition = (estimatedLineCount - 43) * 60;
    }


    List<String> imagesUrls = postDB.getImagesUrls();
    for (String url : imagesUrls) {
        Glide.with(context).load(url).preload();
    }


    try {
        FileOutputStream fOut = context.openFileOutput(LOCAL_PATH, Context.MODE_PRIVATE);
        PdfDocument document = new PdfDocument();
        PdfDocument.PageInfo pageInfo = new PdfDocument.PageInfo.Builder(1800, 3900 + addition + 1000, 1).create();
        PdfDocument.Page page = document.startPage(pageInfo);
        Canvas canvas = page.getCanvas();
        LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        View content;
        if (inflater != null) {
            final int[] count = {0};
            content = inflater.inflate(R.layout.pdf_layout, null);
            ButterKnife.bind(this, content);
            publisherTextView.setText(postDB.getAuthor());
            Date date = new Date(postDB.getDate());
            DateFormat dateFormat = DateFormat.getInstance();
            String format = dateFormat.format(date);
            dateTextView.setText(format);
            titleTextView.setText(postDB.getTitle());
            contentPreviewTextView.setText(postDBContent);
            recyclerViewImages.setLayoutManager(new GridLayoutManager(context, 2));
            recyclerViewImages.setAdapter(new PDFImageAdapter(postDB.getImagesUrls()));
            String text = postDB.getCity() + ", " + postDB.getCountry();
            location.setText(text);
            int measureWidth = View.MeasureSpec.makeMeasureSpec(page.getCanvas().getWidth(), View.MeasureSpec.EXACTLY);
            int measuredHeight = View.MeasureSpec.makeMeasureSpec(page.getCanvas().getHeight(), View.MeasureSpec.EXACTLY);
            content.measure(measureWidth, measuredHeight);
            content.layout(0, 0, page.getCanvas().getWidth(), page.getCanvas().getHeight());
            content.draw(canvas);

        }
        document.finishPage(page);
        document.writeTo(fOut);
        document.close();
        fOut.close();
        return new File(context.getFilesDir().getPath() + "/" + LOCAL_PATH);
    } catch (IOException e) {
        Log.i("error", e.getLocalizedMessage());
        return null;
    }
}

这是我绑定 ViewHolders 的代码

 public void setData(String url) {
    Glide.with(imageView.getContext()).load(url)
            .listener(new RequestListener<Drawable>() {
                @Override
                public boolean onLoadFailed(@Nullable GlideException e, Object model, Target<Drawable> target, boolean isFirstResource) {
                    Timber.d("onLoadFailed");
                    return true;
                }

                @Override
                public boolean onResourceReady(Drawable resource, Object model, Target<Drawable> target, DataSource dataSource, boolean isFirstResource) {
                    Timber.d("onResourceReady");
                    return true;
                }
            })
            .into(imageView);
}

调用数据onBind方法，并调用setData方法。但是从来没有调用过 Glide 的回调。

Answer 1

我使用 iText 库来解决这个问题，

例如，这是我用来添加图像的代码。这样你就不需要任何视图了。

Rectangle pageSize = PageSize.A4;
Document document = new Document();
PdfWriter.getInstance(document, context.openFileOutput(LOCAL_PATH, Context.MODE_PRIVATE));
document.open();
 document.setPageSize(pageSize);
   document.addCreationDate();
   document.addAuthor(context.getString(R.string.pdf_creator));
   document.addCreator(context.getString(R.string.pdf_creator));
Image image = Image.getInstance(filename);
   image.scaleToFit(300f, 150f);
   image.setAbsolutePosition(absoluteX, absoluteY);
   document.add(image);
document.close();

使用 Android 中来自网络 URL 的图像从视图生成 PDF 文件

Generate PDF files from view with Images from network URL in Android

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