android- 通过Intent筛选多种类型文件

android: 通过Intent筛选多种类型文件

一般使用setType()方法来实现文件过滤，如：只显示PDF文件：

     int requestCode = 100;
     Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
     intent.setType("application/pdf");
     intent.addCategory(Intent.CATEGORY_OPENABLE);
     startActivityForResult(intent, requestCode); 

但如果要指定多种类型呢，同时要指定pdf,excel,word,ppt这些类型的文件，那要怎样设置呢？

指定多种类型文件

在网上查了，有些答案是

错误方式1——setType中进行拼接：

intent.setType(“video/*;image/*”);//同时选择视频和图片

错误方式2——调用多次setType：

intent.setType("video/*");
intent.setType("image/*");

这两种方式都是错误的
我们看下源码

/**
     * Set an explicit MIME data type.
     *
     * <p>This is used to create intents that only specify a type and not data,
     * for example to indicate the type of data to return.
     *
     * <p>This method automatically clears any data that was
     * previously set (for example by {@link #setData}).
     *
     * <p><em>Note: MIME type matching in the Android framework is
     * case-sensitive, unlike formal RFC MIME types.  As a result,
     * you should always write your MIME types with lower case letters,
     * or use {@link #normalizeMimeType} or {@link #setTypeAndNormalize}
     * to ensure that it is converted to lower case.</em>
     *
     * @param type The MIME type of the data being handled by this intent.
     *
     * @return Returns the same Intent object, for chaining multiple calls
     * into a single statement.
     *
     * @see #getType
     * @see #setTypeAndNormalize
     * @see #setDataAndType
     * @see #normalizeMimeType
     */
    public Intent setType(String type) {
        mData = null;
        mType = type;
        return this;
    }

我们可以看到，setType每次都是重新赋值，没有添加到list和数组中，因此这两种方式是实现不了指定多种类型文件的。
既然这种方式实现不了，那么Intent会不会提供字段以便我们传递过滤数据，我们通过官方文档及源码，发现Intent提供了EXTRA_MIME_TYPES这个字段来传递，而且是数组类型：

/**
     * Extra used to communicate a set of acceptable MIME types. The type of the
     * extra is {@code String[]}. Values may be a combination of concrete MIME
     * types (such as "image/png") and/or partial MIME types (such as
     * "audio/*").
     *
     * @see #ACTION_GET_CONTENT
     * @see #ACTION_OPEN_DOCUMENT
     */
    public static final String EXTRA_MIME_TYPES = "android.intent.extra.MIME_TYPES";

因此结果就简单了,我们要指定ppt,word,excel,pdf类型的文件，代码如下

public static void openDirChooseFile(Activity activity, int requestCode, String[] mimeTypes) {
        Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
        if (mimeTypes != null) {
            intent.putExtra(Intent.EXTRA_MIME_TYPES, mimeTypes);
        }
        intent.setType("*/*");
        intent.addCategory(Intent.CATEGORY_OPENABLE);
        // intent.putExtra(Intent.EXTRA_ALLOW_MULTIPLE, true);//多选
        activity.startActivityForResult(intent, requestCode);
    }
 public static void chooseFile(Activity activity, int requestCode) {
        String[] mimeTypes = {MimeType.DOC, MimeType.DOCX, MimeType.PDF, MimeType.PPT, MimeType.PPTX, MimeType.XLS, MimeType.XLSX};
        FileUtil.openDirChooseFile(activity, requestCode, mimeTypes);
    }

MimeType文件

public class MimeType {
    public static final String DOC = "application/msword";
    public static final String DOCX = "application/vnd.openxmlformats-officedocument.wordprocessingml.document";
    public static final String XLS = "application/vnd.ms-excel application/x-excel";
    public static final String XLSX = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
    public static final String PPT = "application/vnd.ms-powerpoint";
    public static final String PPTX = "application/vnd.openxmlformats-officedocument.presentationml.presentation";
    public static final String PDF = "application/pdf";
}

MimeType 文件列表参考

扩展名	文档类型	MIME 类型
.aac	AAC audio	audio/aac
.abw	AbiWord document	application/x-abiword
.arc	Archive document (multiple files embedded)	application/x-freearc
.avi	AVI: Audio Video Interleave	video/x-msvideo
.azw	Amazon Kindle eBook format	application/vnd.amazon.ebook
.bin	Any kind of binary data	application/octet-stream
.bmp	Windows OS/2 Bitmap Graphics	image/bmp
.bz	BZip archive	application/x-bzip
.bz2	BZip2 archive	application/x-bzip2
.csh	C-Shell script	application/x-csh
.css	Cascading Style Sheets (CSS)	text/css
.csv	Comma-separated values (CSV)	text/csv
.doc	Microsoft Word	application/msword
.docx	Microsoft Word (OpenXML)	application/vnd.openxmlformats-officedocument.wordprocessingml.document
.eot	MS Embedded OpenType fonts	application/vnd.ms-fontobject
.epub	Electronic publication (EPUB)	application/epub+zip
.gif	Graphics Interchange Format (GIF)	image/gif
`.htm
.html`	HyperText Markup Language (HTML)	text/html
.ico	Icon format	image/vnd.microsoft.icon
.ics	iCalendar format	text/calendar
.jar	Java Archive (JAR)	application/java-archive
.jpeg
.jpg	JPEG images	image/jpeg
.js	JavaScript	text/javascript
.json	JSON format	application/json
.jsonld	JSON-LD format	application/ld+json
.mid
.midi	Musical Instrument Digital Interface (MIDI)	audio/midi audio/x-midi
.mjs	JavaScript module	text/javascript
.mp3	MP3 audio	audio/mpeg
.mpeg	MPEG Video	video/mpeg
.mpkg	Apple Installer Package	application/vnd.apple.installer+xml
.odp	OpenDocument presentation document	application/vnd.oasis.opendocument.presentation
.ods	OpenDocument spreadsheet document	application/vnd.oasis.opendocument.spreadsheet
.odt	OpenDocument text document	application/vnd.oasis.opendocument.text
.oga	OGG audio	audio/ogg
.ogv	OGG video	video/ogg
.ogx	OGG	application/ogg
.otf	OpenType font	font/otf
.png	Portable Network Graphics	image/png
.pdf	Adobe Portable Document Format (PDF)	application/pdf
.ppt	Microsoft PowerPoint	application/vnd.ms-powerpoint
.pptx	Microsoft PowerPoint (OpenXML)	application/vnd.openxmlformats-officedocument.presentationml.presentation
.rar	RAR archive	application/x-rar-compressed
.rtf	Rich Text Format (RTF)	application/rtf
.sh	Bourne shell script	application/x-sh
.svg	Scalable Vector Graphics (SVG)	image/svg+xml
.swf	Small web format (SWF) or Adobe Flash document	application/x-shockwave-flash
.tar	Tape Archive (TAR)	application/x-tar
`.tif
.tiff`	Tagged Image File Format (TIFF)	image/tiff
.ttf	TrueType Font	font/ttf
.txt	Text, (generally ASCII or ISO 8859-n)	text/plain
.vsd	Microsoft Visio	application/vnd.visio
.wav	Waveform Audio Format	audio/wav
.weba	WEBM audio	audio/webm
.webm	WEBM video	video/webm
.webp	WEBP image	image/webp
.woff	Web Open Font Format (WOFF)	font/woff
.woff2	Web Open Font Format (WOFF)	font/woff2
.xhtml	XHTML	application/xhtml+xml
.xls	Microsoft Excel	application/vnd.ms-excel
.xlsx	Microsoft Excel (OpenXML)	application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
.xml	XML	application/xml 代码对普通用户来说不可读 (RFC 3023, section 3)
text/xml 代码对普通用户来说可读 (RFC 3023, section 3)
.xul	XUL	application/vnd.mozilla.xul+xml
.zip	ZIP archive	application/zip
.3gp	3GPP audio/video container	video/3gpp
audio/3gpp（若不含视频）
.3g2	3GPP2 audio/video container	video/3gpp2
audio/3gpp2（若不含视频）
.7z	7-zip archive	application/x-7z-compressed