本地和asset点9图加载

在加载本地或者asset中的点9图时，实际上就是先加载为bitmap对象，然后判断是否有NinePatchChunk，有就是点9图，获取其属性，封装为NinePatchDrawable即可正常使用。工具类代码如下：

public class NinePatchUtils {    private final static int NO_COLOR = 0x00000001;    private NinePatchUtils() {    }    /***     * 读取assets下图片,此处修改了NinePatchDrawable不能正常读取问题，     * e.g     * Drawable bg = NinePatchTool.decodeDrawableFromAsset(this, path);     * <p>     * assetPath:如果存在子目录，则需要写子目录名称，如下："aaa/log.png"     *     * @param context     * @param assetPath     * @return     * @throws Exception     */    public static Drawable decodeDrawableFromAsset(Context context,                                                   String assetPath) throws Exception {        Bitmap bitmap = readFromAsset(context, assetPath);        if (bitmap.getNinePatchChunk() == null) {            BitmapDrawable bitmapDrawable = new BitmapDrawable(bitmap);            return bitmapDrawable;        } else {            Rect paddingRect = new Rect();            readPaddingFromChunk(bitmap.getNinePatchChunk(), paddingRect);            return new NinePatchDrawable(context.getResources(),                    bitmap, bitmap.getNinePatchChunk(), paddingRect, null);        }    }    /**     * @param context     * @param assetPath     * @return     * @throws Exception     */    public static Drawable decodeDrawableFromOtherResour(Context context,                                                         String assetPath) throws Exception {        Bitmap bitmap = decodeFromFile(assetPath);        if (bitmap.getNinePatchChunk() == null) {            BitmapDrawable bitmapDrawable = new BitmapDrawable(bitmap);            return bitmapDrawable;        } else {            Rect paddingRect = new Rect();            readPaddingFromChunk(bitmap.getNinePatchChunk(), paddingRect);            return new NinePatchDrawable(context.getResources(),                    bitmap, bitmap.getNinePatchChunk(), paddingRect, null);        }    }    /***     * 通过流读取图片     *     * @param in     * @return     * @throws Exception     */    public static Bitmap decodeFromStream(InputStream in) throws Exception {        Bitmap srcBm = BitmapFactory.decodeStream(in);        byte[] chunk = readChunk(srcBm);        boolean isNinePatchChunk = NinePatch.isNinePatchChunk(chunk);        if (isNinePatchChunk) {            Bitmap tgtBm = Bitmap.createBitmap(srcBm, 1, 1,                    srcBm.getWidth() - 2, srcBm.getHeight() - 2);            srcBm.recycle();            Field f = tgtBm.getClass().getDeclaredField("mNinePatchChunk");            f.setAccessible(true);            f.set(tgtBm, chunk);            return tgtBm;        } else {            return srcBm;        }    }    /***     * 通过制定目录读取文件     *     * @param path     * @return     * @throws Exception     */    public static Bitmap decodeFromFile(String path) throws Exception {        InputStream in = new FileInputStream(path);        Bitmap bm = decodeFromStream(in);        in.close();        return bm;    }    /***     * 读取Assets下图片包括.9.png     *     * @param context     * @param ninePatchPngPath     * @return     * @throws Exception     */    public static Bitmap readFromAsset(Context context,                                       String ninePatchPngPath) throws Exception {        InputStream is = context.getAssets().open(ninePatchPngPath);        Bitmap bm = decodeFromStream(is);        is.close();        return bm;    }    public static void readPaddingFromChunk(byte[] chunk, Rect paddingRect) {        paddingRect.left = getInt(chunk, 12);        paddingRect.right = getInt(chunk, 16);        paddingRect.top = getInt(chunk, 20);        paddingRect.bottom = getInt(chunk, 24);    }    public static byte[] readChunk(Bitmap resourceBmp) throws IOException {        final int BM_W = resourceBmp.getWidth();        final int BM_H = resourceBmp.getHeight();        int xPointCount = 0;        int yPointCount = 0;        int xBlockCount = 0;        int yBlockCount = 0;        ByteArrayOutputStream bao = new ByteArrayOutputStream();        for (int i = 0; i < 32; i++) {            bao.write(0);        }        {            int[] pixelsTop = new int[BM_W - 2];            resourceBmp.getPixels(pixelsTop, 0, BM_W, 1, 0, BM_W - 2, 1);            boolean topFirstPixelIsBlack = pixelsTop[0] == Color.BLACK;            boolean topLastPixelIsBlack = pixelsTop[pixelsTop.length - 1] == Color.BLACK;            int tmpLastColor = Color.TRANSPARENT;            for (int i = 0, len = pixelsTop.length; i < len; i++) {                if (tmpLastColor != pixelsTop[i]) {                    xPointCount++;                    writeInt(bao, i);                    tmpLastColor = pixelsTop[i];                }            }            if (topLastPixelIsBlack) {                xPointCount++;                writeInt(bao, pixelsTop.length);            }            xBlockCount = xPointCount + 1;            if (topFirstPixelIsBlack) {                xBlockCount--;            }            if (topLastPixelIsBlack) {                xBlockCount--;            }        }        {            int[] pixelsLeft = new int[BM_H - 2];            resourceBmp.getPixels(pixelsLeft, 0, 1, 0, 1, 1, BM_H - 2);            boolean firstPixelIsBlack = pixelsLeft[0] == Color.BLACK;            boolean lastPixelIsBlack = pixelsLeft[pixelsLeft.length - 1] == Color.BLACK;            int tmpLastColor = Color.TRANSPARENT;            for (int i = 0, len = pixelsLeft.length; i < len; i++) {                if (tmpLastColor != pixelsLeft[i]) {                    yPointCount++;                    writeInt(bao, i);                    tmpLastColor = pixelsLeft[i];                }            }            if (lastPixelIsBlack) {                yPointCount++;                writeInt(bao, pixelsLeft.length);            }            yBlockCount = yPointCount + 1;            if (firstPixelIsBlack) {                yBlockCount--;            }            if (lastPixelIsBlack) {                yBlockCount--;            }        }        {            for (int i = 0; i < xBlockCount * yBlockCount; i++) {                writeInt(bao, NO_COLOR);            }        }        byte[] data = bao.toByteArray();        data[0] = 1;        data[1] = (byte) xPointCount;        data[2] = (byte) yPointCount;        data[3] = (byte) (xBlockCount * yBlockCount);        dealPaddingInfo(resourceBmp, data);        return data;    }    private static void dealPaddingInfo(Bitmap bm, byte[] data) {        { // padding left & padding right            int[] bottomPixels = new int[bm.getWidth() - 2];            bm.getPixels(bottomPixels, 0, bottomPixels.length, 1,                    bm.getHeight() - 1, bottomPixels.length, 1);            for (int i = 0; i < bottomPixels.length; i++) {                if (Color.BLACK == bottomPixels[i]) { // padding left                    writeInt(data, 12, i);                    break;                }            }            for (int i = bottomPixels.length - 1; i >= 0; i--) {                if (Color.BLACK == bottomPixels[i]) { // padding right                    writeInt(data, 16, bottomPixels.length - i - 2);                    break;                }            }        }        { // padding top & padding bottom            int[] rightPixels = new int[bm.getHeight() - 2];            bm.getPixels(rightPixels, 0, 1, bm.getWidth() - 1, 0, 1,                    rightPixels.length);            for (int i = 0; i < rightPixels.length; i++) {                if (Color.BLACK == rightPixels[i]) { // padding top                    writeInt(data, 20, i);                    break;                }            }            for (int i = rightPixels.length - 1; i >= 0; i--) {                if (Color.BLACK == rightPixels[i]) { // padding bottom                    writeInt(data, 24, rightPixels.length - i - 2);                    break;                }            }        }    }    private static void writeInt(OutputStream out, int v) throws IOException {        out.write((v >> 0) & 0xFF);        out.write((v >> 8) & 0xFF);        out.write((v >> 16) & 0xFF);        out.write((v >> 24) & 0xFF);    }    private static void writeInt(byte[] b, int offset, int v) {        b[offset + 0] = (byte) (v >> 0);        b[offset + 1] = (byte) (v >> 8);        b[offset + 2] = (byte) (v >> 16);        b[offset + 3] = (byte) (v >> 24);    }    private static int getInt(byte[] bs, int from) {        int b1 = bs[from + 0];        int b2 = bs[from + 1];        int b3 = bs[from + 2];        int b4 = bs[from + 3];        int i = b1 | (b2 << 8) | (b3 << 16) | b4 << 24;        return i;    }    /**     * print chunk info from bitmap     */    public static void printChunkInfo(Bitmap bm) {        byte[] chunk = bm.getNinePatchChunk();        if (null == chunk) {            System.out.println("can't find chunk info from this bitmap(" + bm                    + ")");            return;        }        int xLen = chunk[1];        int yLen = chunk[2];        int cLen = chunk[3];        StringBuilder sb = new StringBuilder();        int peddingLeft = getInt(chunk, 12);        int paddingRight = getInt(chunk, 16);        int paddingTop = getInt(chunk, 20);        int paddingBottom = getInt(chunk, 24);        sb.append("peddingLeft=" + peddingLeft);        sb.append("\r\n");        sb.append("paddingRight=" + paddingRight);        sb.append("\r\n");        sb.append("paddingTop=" + paddingTop);        sb.append("\r\n");        sb.append("paddingBottom=" + paddingBottom);        sb.append("\r\n");        sb.append("x info=");        for (int i = 0; i < xLen; i++) {            int vv = getInt(chunk, 32 + i * 4);            sb.append("," + vv);        }        sb.append("\r\n");        sb.append("y info=");        for (int i = 0; i < yLen; i++) {            int vv = getInt(chunk, xLen * 4 + 32 + i * 4);            sb.append("," + vv);        }        sb.append("\r\n");        sb.append("color info=");        for (int i = 0; i < cLen; i++) {            int vv = getInt(chunk, xLen * 4 + yLen * 4 + 32 + i * 4);            sb.append("," + vv);        }        System.err.println("" + sb);    }}

朋友们，仅供参考，如有错误，敬请指正。