在webview中打开多个页面并创建PDF [英] Open several pages in webview and create PDF
问题描述
我正在尝试构建一个应用程序，以从Web视图中的多个页面创建PDF.
I am trying to build an app to create a PDF from several pages in webview.
作为初学者，我很高兴发现了以下内容: Android从具有多个页面的webview创建pdf文档
As beginner i was happy i found this: Android create pdf document from webview with multiple pages
但是我无法正确处理. 在PDF中创建的页面数量很好，但内容却不行. 创建具有(在这种情况下)3个相似页面的PDF.均显示调用该方法之前的webview. 完成创建PDF后，将加载url数组的最后一个URL.
However I am not able to get it right. The amount of pages created in the PDF is fine, but the content is not. A PDF with (in this case) 3 similar pages is created. All showing the webview of before the method was called. Once finished creating the PDF, the last url of the url array loads.
我如何才能实现仅在将新的URL加载到Webview中之后创建pdf页面?
我确实尝试过使用延迟，但这似乎不是问题. 如果延迟，则会先创建pdf文件，然后才打开页面.
I did try to use delay, but that does not seem to be the issue. If delayed, the pdf is created first and pages are opened up only after.
我确实尝试从onPageFinished()内部调用pdf创建. 它也没有做这项工作.
I did try to call the pdf creation from within onPageFinished(). It did not do the job either.
也许我确实使用了所有这些错误. 这是我的代码现在的样子:
Maybe i did use all this wrong. Here is what my code looks like right now:
//Create folder
String baseDir = Environment.getExternalStorageDirectory().getAbsolutePath();
String dirName = "exampledirectory";
File newdir = new File(baseDir + File.separator + dirName);
newdir.mkdirs();
//Create PDF
String fileName = "example.pdf";
String fileNameWithPath = newdir + File.separator + fileName;
//Create document
PdfDocument document = new PdfDocument();
String[] urlArr = {"exampleurl1.com", "exampleurl2.com", "exampleurl3.com"};
for (int i = 0; i < urlArr.length; i++) {
mWebView.loadUrl(urlArr[i]);
PdfDocument.PageInfo pageInfo = new PdfDocument.PageInfo.Builder(mWebView.getMeasuredWidth(), mWebView.getContentHeight(), i).create();
// start [i]st page
PdfDocument.Page page = document.startPage(pageInfo);
// draw on the page
View content = mWebView;
content.draw(page.getCanvas());
// finish [i]st page
document.finishPage(page);
}
FileOutputStream fos;
try {
fos = new FileOutputStream(fileNameWithPath, false);
// write the document content
document.writeTo(fos);
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
document.close();
推荐答案
我找到了适合我的解决方案. 感觉有点奇怪，但确实可以.
I found a solution that works for me. It feels a bit odd, but it does the job.
正如我上面提到的，onPageFinished()在我的第一次尝试中不起作用，因为调用该页面时尚未呈现该页面. 现在，我再次尝试从onPageFinished()调用另一个方法，然后再调用PDFbuilder方法.通过这种解决方法"，我能够从所有URL构建PDF. 这是代码:
As I mentioned above onPageFinished() did not work on my first tries, cause the page is not rendered yet when called. Now I tried again calling another method from onPageFinished() which then calls the PDFbuilder Methods. With this "workaround" I was able to build a PDF from all URLs. Here`s the code:
private class printPDFFromWebcontent {
int i = 0;
public String pageURL = "exampleURL";
public PdfDocument document = new PdfDocument();
public String fileNameWithPath ="blank.pdf";
private void runPDFBuilder() {
zWebView = (WebView) findViewById(R.id.activity_main_webview);
WebSettings webSettings = zWebView.getSettings();
webSettings.setJavaScriptEnabled(true);
zWebView.setWebViewClient(new WebViewClient() {
@Override
public void onPageFinished(WebView view, String url) {
super.onPageFinished(zWebView, url);
i++;
openNextPage();
}
private void openNextPage() {
String nextPage = pageURL + "?page=" + String.valueOf(i + 1); //This works with my specific target URLs. You may want to use an URL array.
if (i == 1) {
zWebView.loadUrl(nextPage);
createPDFNow();
}
if (i == 2) {
zWebView.loadUrl(nextPage);
addPageToPDF();
}
if (i == 3) {
zWebView.loadUrl(nextPage);
addPageToPDF();
}
if (i == 4) {
mWebView.loadUrl("whateverYouWantToShowIfFinishedURL");
//Not added to the PDF
//Reason is to trigger onPageFinished() once more. You could probably i++ here and call openNextPage() from within.
addPageToPDF(); //Add the last webview content to PDF.
}
if (i == 5) {
createPDFNow();
Toast.makeText(getApplicationContext(), "Finito.", Toast.LENGTH_SHORT).show();
savePDF();
return;
}
}
public void createPDFNow(){
String baseDir = Environment.getExternalStorageDirectory().getAbsolutePath();
String dirName = "example";
File newdir = new File(baseDir + File.separator + dirName);
newdir.mkdirs();
String fileName = "example.pdf";
fileNameWithPath = newdir + File.separator + fileName;
}
public void addPageToPDF() {
PdfDocument.PageInfo pageInfo = new PdfDocument.PageInfo.Builder(zWebView.getMeasuredWidth(), zWebView.getContentHeight(), i).create();
PdfDocument.Page page = document.startPage(pageInfo);
View content = zWebView;
content.draw(page.getCanvas());
document.finishPage(page);
}
public void savePDF(){
FileOutputStream fos;
try {
fos = new FileOutputStream(fileNameWithPath, false);
document.writeTo(fos);
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
document.close();
}
});
zWebView.getSettings().setUseWideViewPort(true);
zWebView.getSettings().setLoadWithOverviewMode(true);
zWebView.loadUrl("URL1");
return;
}
但是，如果有一个更明智的解决方案:我想学习.
However if there is a smarter solution: I`d like to learn.
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