分类: Android开发笔记

Android预览pdf文档

谷歌为我们提供了PdfRender工具类对pdf文档进行渲染，首先看一下PdfRender的构造方法：

/**
 * Creates a new instance.
 * <p>
 * <strong>Note:</strong> The provided file descriptor must be <strong>seekable</strong>,
 * i.e. its data being randomly accessed, e.g. pointing to a file.
 * </p>
 * <p>
 * <strong>Note:</strong> This class takes ownership of the passed in file descriptor
 * and is responsible for closing it when the renderer is closed.
 * </p>
 * <p>
 * If the file is from an untrusted source it is recommended to run the renderer in a separate,
 * isolated process with minimal permissions to limit the impact of security exploits.
 * </p>
 *
 * @param input Seekable file descriptor to read from.
 *
 * @throws java.io.IOException If an error occurs while reading the file.
 * @throws java.lang.SecurityException If the file requires a password or
 *         the security scheme is not supported.
 */
public PdfRenderer(@NonNull ParcelFileDescriptor input){
  //略...
}

可以看构造方法中的参数是ParcelFileDescriptor的一个实例，那么ParcelFileDescriptor类是做什么的呢？ParcelFileDescriptor是Android 提供的一种数据结构，支持数据的写入和写出。我们通过ParcelFileDescriptor#open 建立文件和ParcelFileDescriptor的联系

2019-11-05

子线程不可以更新UI吗

Android开发笔记

Android预览pdf文档

最新文章

分类

归档

标签

标签云

链接

Your browser is out-of-date!