【Android】使用android-gif-drawable包加载GIF动图

【导包】

首先需要导入android-gif-drawable包，请参考：【android】实用教程：导入android-gif-drawable包，不用在github下载（android studio 3.1.2）

【使用】

一、在layout中添加gifimageview控件，该控件既可以加载gif动态图，也可以加载jpg、png静态图。不需要设置src属性。

二、在java文件中，给gifimageview设置src属性，加载gif动态图。

1、获取gifimageview控件。

        gifimageview gifimageview = findviewbyid(r.id.image);

2、实例化gifdrawable对象，共有11种方法。

（1）resouces文件

：

	/**
	 * creates drawable from resource.
	 *
	 * @param res resources to read from
	 * @param id  resource id (raw or drawable)
	 * @throws notfoundexception    if the given id does not exist.
	 * @throws ioexception          when opening failed
	 * @throws nullpointerexception if res is null
	 */
	public gifdrawable(@nonnull resources res, @rawres @drawableres int id) throws notfoundexception, ioexception {
		this(res.openrawresourcefd(id));
		final float densityscale = gifviewutils.getdensityscale(res, id);
		mscaledheight = (int) (mnativeinfohandle.getheight() * densityscale);
		mscaledwidth = (int) (mnativeinfohandle.getwidth() * densityscale);
	}

示例：

            // resources file
            gifdrawable giffromassets = new gifdrawable(getresources(), r.mipmap.timg);

（2）assets文件

源码：

	/**
	 * creates drawable from asset.
	 *
	 * @param assets    assetmanager to read from
	 * @param assetname name of the asset
	 * @throws ioexception          when opening failed
	 * @throws nullpointerexception if assets or assetname is null
	 */
	public gifdrawable(@nonnull assetmanager assets, @nonnull string assetname) throws ioexception {
		this(assets.openfd(assetname));
	}

示例：

            // assets file
            gifdrawable giffromassets = new gifdrawable(getassets(), "timg.gif");

（3）文件路径

源码：

	/**
	 * constructs drawable from given file path.

	 * only metadata is read, no graphic data is decoded here.
	 * in practice can be called from main thread. however it will violate
	 * {@link strictmode} policy if disk reads detection is enabled.

	 *
	 * @param filepath path to the gif file
	 * @throws ioexception          when opening failed
	 * @throws nullpointerexception if filepath is null
	 */
	public gifdrawable(@nonnull string filepath) throws ioexception {
		this(new gifinfohandle(filepath), null, null, true);
	}

示例：

            // path to the gif file
            gifdrawable giffrompath = new gifdrawable("/path/timg.gif");

（4）file文件

源码：

	/**
	 * equivalent to {@code} gifdrawable(file.getpath())}
	 *
	 * @param file the gif file
	 * @throws ioexception          when opening failed
	 * @throws nullpointerexception if file is null
	 */
	public gifdrawable(@nonnull file file) throws ioexception {
		this(file.getpath());
	}

示例：

            // the gif file
            file giffile = new file(getfilesdir(), "timg.gif");
            gifdrawable giffromfile = new gifdrawable(giffile);

（5）输入流stream to read from

源码：

	/**
	 * creates drawable from inputstream.
	 * inputstream must support marking, illegalargumentexception will be thrown otherwise.
	 *
	 * @param stream stream to read from
	 * @throws ioexception              when opening failed
	 * @throws illegalargumentexception if stream does not support marking
	 * @throws nullpointerexception     if stream is null
	 */
	public gifdrawable(@nonnull inputstream stream) throws ioexception {
		this(new gifinfohandle(stream), null, null, true);
	}

（6）assetfiledescriptor

 

源码：

	/**
	 * creates drawable from assetfiledescriptor.
	 * convenience wrapper for {@link gifdrawable#gifdrawable(filedescriptor)}
	 *
	 * @param afd source
	 * @throws nullpointerexception if afd is null
	 * @throws ioexception          when opening failed
	 */
	public gifdrawable(@nonnull assetfiledescriptor afd) throws ioexception {
		this(new gifinfohandle(afd), null, null, true);
	}

 

示例：

     // creates drawable from assetfiledescriptor
     assetfiledescriptor assetfiledescriptor = getassets().openfd("timg.gif");
     gifdrawable giffromafd = new gifdrawable(assetfiledescriptor);

（7）filedescriptor

源码：

	/**
	 * creates drawable from filedescriptor
	 *
	 * @param fd source
	 * @throws ioexception          when opening failed
	 * @throws nullpointerexception if fd is null
	 */
	public gifdrawable(@nonnull filedescriptor fd) throws ioexception {
		this(new gifinfohandle(fd), null, null, true);
	}

 

示例：

     // creates drawable from filedescriptor
     filedescriptor filedescriptor = new randomaccessfile("/path/timg.gif", "r").getfd();
     gifdrawable giffromfd = new gifdrawable(filedescriptor);

（8）raw gif bytes

源码：

	 * creates drawable from byte array.

	 * it can be larger than size of the gif data. bytes beyond gif terminator are not accessed.
	 *
	 * @param bytes raw gif bytes
	 * @throws ioexception          if bytes does not contain valid gif data
	 * @throws nullpointerexception if bytes are null
	 */
	public gifdrawable(@nonnull byte[] bytes) throws ioexception {
		this(new gifinfohandle(bytes), null, null, true);
	}

 

（9）bytebuffer

源码：

	/**
	 * creates drawable from {@link bytebuffer}. only direct buffers are supported.
	 * buffer can be larger than size of the gif data. bytes beyond gif terminator are not accessed.
	 *
	 * @param buffer buffer containing gif data
	 * @throws ioexception          if buffer does not contain valid gif data or is indirect
	 * @throws nullpointerexception if buffer is null
	 */
	public gifdrawable(@nonnull bytebuffer buffer) throws ioexception {
		this(new gifinfohandle(buffer), null, null, true);
	}

 

（10）contentresolver

源码：

	/**
	 * creates drawable from {@link android.net.uri} which is resolved using {@code resolver}.
	 * {@link android.content.contentresolver#openassetfiledescriptor(android.net.uri, string)}
	 * is used to open an uri.
	 *
	 * @param uri      gif uri, cannot be null.
	 * @param resolver resolver used to query {@code uri}, can be null for file:// scheme uris
	 * @throws ioexception if resolution fails or destination is not a gif.
	 */
	public gifdrawable(@nullable contentresolver resolver, @nonnull uri uri) throws ioexception {
		this(gifinfohandle.openuri(resolver, uri), null, null, true);
	}

 

（11）inputsource

源码：

	/**
	 * creates drawable from {@link inputsource}.
	 *
	 * @param inputsource                the {@link inputsource} concrete subclass used to construct {@link gifdrawable}.
	 * @param olddrawable                the old drawable that will be reused to save the memory. can be null.
	 * @param executor                   the executor for rendering tasks. can be null.
	 * @param isrenderingtriggeredondraw true if rendering of the next frame is scheduled after drawing current one, false otherwise.
	 * @param options                    options controlling various gif parameters.
	 * @throws ioexception if input source is invalid.
	 */
	protected gifdrawable(@nonnull inputsource inputsource,
	                      @nullable gifdrawable olddrawable,
	                      @nullable scheduledthreadpoolexecutor executor,
	                      boolean isrenderingtriggeredondraw,
	                      @nonnull gifoptions options) throws ioexception {

		this(inputsource.createhandlewith(options), olddrawable, executor, isrenderingtriggeredondraw);
	}

3、设置gifimageview控件的src。

     gifimageview.setimagedrawable(gifdrawable);

【注意】

gifimageview控件可以加载静态图，步骤如下：

        drawable drawable = getdrawable(r.mipmap.ic_launcher);
        gifimageview.setimagedrawable(drawable);

gifdrawable类的对象读取静态图可能会报错。