如何在内存中创建pdf文件

编程入门行业动态更新时间:2024-10-24 22:19:38

本文介绍了如何在内存中创建pdf文件的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！问题描述 @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_pdftest); Button Btgerar = (Button) findViewById(R.id.gerarpdf); Btgerar.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { CriarPDF(); } }); } public void CriarPDF() { String FILE = Environment.getExternalStorageDirectory().toString() + "/PDF/" + "Ficha.pdf"; EditText txt = (EditText) findViewById(R.id.editText); // Create New Blank Document Document document = new Document(PageSize.A4); // Create Directory in External Storage String root = Environment.getExternalStorageDirectory().toString(); File myDir = new File(root + "/PDF"); myDir.mkdirs(); // Create Pdf Writer for Writting into New Created Document try { PdfWriter.getInstance(document, new FileOutputStream(FILE)); // Open Document for Writting into document document.open(); document.add(new Paragraph(txt.getText().toString())); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (DocumentException e) { e.printStackTrace(); } // Close Document after writting all content document.close(); Toast.makeText(this, "PDF File is Created. Location : " + FILE, Toast.LENGTH_LONG).show(); // Create new Page in PDF document.newPage(); } }

我已宣布在android清单中

I have declared in android manifest

使用权限android：name =android.permission.WRITE_EXTERNAL_STORAGE

和build gradle版本是：

and build gradle version is :

compileSdkVersion 24 buildToolsVersion '24.0.0' minSdkVersion 8 targetSdkVersion 24

应用程序可以正常运行，但是可以不创建pdf文件，我找不到。

The application can run normally, but can't create pdf file and I can't find.

推荐答案

如果我看一下你问题的主题，那么答案就是答案很简单。你正在使用 FileOutputStream 在文件系统上创建一个PDF。在主题中你问：如何在内存中创建pdf文件？这很简单.iText接受任何 OutputStream ，所以答案是：使用 ByteArrayOutputStream 而不是 FileOutputStream 。

If I look at the subject of your question, then the answer is simple. You are creating a PDF on the file system using a FileOutputStream. In the subject you ask: "How to create pdf files in memory?" That is simple. iText accepts any OutputStream, so the answer is: use a ByteArrayOutputStream instead of a FileOutputStream.

参见使用iText，在内存上生成一个在磁盘上生成的PDF而不是

Document document = new Document(); ByteArrayOutputStream out = new ByteArrayOutputStream(); PdfWriter writer = PdfWriter.getInstance(documento, out); (...) byte[] pdf = out.getBytes();

但是，为什么要在Android设备的内存中创建PDF？你打算用这些字节做什么？如果您只有 byte [] ，则无法显示PDF。在我对这个问题的回答中解释了这一点：显示存储在ByteArrayOutputStream中的PDF文档（不在文件中）

However, why would you want to create a PDF in memory on an Android device? What are you going to do with those bytes? You can't show the PDF if you only have a byte[]. That is explained in my answer to this question: Display PDF document stored in a ByteArrayOutputStream (not in a file)

您还会注意到以下问题仍未得到答复（因为没有答案）：如何在Android上将ByteArrayOutputStream可视化为PDF？

You will also notice that the following question remained unanswered (because there is no answer): How to visualize a ByteArrayOutputStream as PDF on Android?

您的问题在最后更改主题，您写道：应用程序可以正常运行，但无法创建pdf文件，我找不到。这听起来好像你不知道如何在Android上的文件系统中编写PDF。这与你在这个主题中提到的问题不同。之前已经多次回答过这个问题：

Your question changes subject towards the end, where you write: "The application can run normally, but can't create pdf file and I can't find." This sounds as if you don't know how to write a PDF to the file system on Android. That's a different question than what you mention in the subject. That question has been answered many times before: