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我需要从可绘制文件夹之外加载 9-patch 文件。例如，这样我的应用程序就可以从服务器下载新皮肤。我发现在制作 .apk 时会编译存储在可绘制文件夹中的 9-patch 图像。从 assets 文件夹中读取的完全相同的文件没有 9-patch 块。因此，制作 .apk 的行为是在 drawable 文件夹中编译源 9-patch 文件，而不是在 assets 目录中。

如何自己编译一个 9-patch 文件，以便我可以将它安装在 assets 目录中？是否有（批处理）工具可以将源代码转换为带有 9-patch 块的编译版本？如果可能的话，我真的非常喜欢不必使用 Eclipse/Ant 来构建一个 .apk，然后将其拆开以提取已编译的 9-patch 文件。

现在我只想能够从资产目录中读取（例如，每个皮肤都有一个子目录）以保持简单。下一步是编译源图像以添加到 9-patch 块中。之后我会担心即时下载到 /data 文件夹——如果我不能编译 9-patch 文件，那么添加服务器端的工作就没有什么意义了。

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2 回答 2

10

没有简单的方法可以做到这一点。9-patch 编译由 aapt 完成，相当简单：它丢弃黑色边框并将其内容编码到 PNG 块中。编写一个做类似事情的工具对你来说是相当微不足道的。请注意，您甚至不需要使用相同的格式。如果您查看文档中的各种 NinePatch API，您将看到您可以提交自己的“块”（对拉伸区域和填充进行编码）。块 byte[] 数组的结构解释如下：

/**
 * This chunk specifies how to split an image into segments for
 * scaling.
 *
 * There are J horizontal and K vertical segments.  These segments divide
 * the image into J*K regions as follows (where J=4 and K=3):
 *
 *      F0   S0    F1     S1
 *   +-----+----+------+-------+
 * S2|  0  |  1 |  2   |   3   |
 *   +-----+----+------+-------+
 *   |     |    |      |       |
 *   |     |    |      |       |
 * F2|  4  |  5 |  6   |   7   |
 *   |     |    |      |       |
 *   |     |    |      |       |
 *   +-----+----+------+-------+
 * S3|  8  |  9 |  10  |   11  |
 *   +-----+----+------+-------+
 *
 * Each horizontal and vertical segment is considered to by either
 * stretchable (marked by the Sx labels) or fixed (marked by the Fy
 * labels), in the horizontal or vertical axis, respectively. In the
 * above example, the first is horizontal segment (F0) is fixed, the
 * next is stretchable and then they continue to alternate. Note that
 * the segment list for each axis can begin or end with a stretchable
 * or fixed segment.
 *
 * The relative sizes of the stretchy segments indicates the relative
 * amount of stretchiness of the regions bordered by the segments.  For
 * example, regions 3, 7 and 11 above will take up more horizontal space
 * than regions 1, 5 and 9 since the horizontal segment associated with
 * the first set of regions is larger than the other set of regions.  The
 * ratios of the amount of horizontal (or vertical) space taken by any
 * two stretchable slices is exactly the ratio of their corresponding
 * segment lengths.
 *
 * xDivs and yDivs point to arrays of horizontal and vertical pixel
 * indices.  The first pair of Divs (in either array) indicate the
 * starting and ending points of the first stretchable segment in that
 * axis. The next pair specifies the next stretchable segment, etc. So
 * in the above example xDiv[0] and xDiv[1] specify the horizontal
 * coordinates for the regions labeled 1, 5 and 9.  xDiv[2] and
 * xDiv[3] specify the coordinates for regions 3, 7 and 11. Note that
 * the leftmost slices always start at x=0 and the rightmost slices
 * always end at the end of the image. So, for example, the regions 0,
 * 4 and 8 (which are fixed along the X axis) start at x value 0 and
 * go to xDiv[0] and slices 2, 6 and 10 start at xDiv[1] and end at
 * xDiv[2].
 *
 * The array pointed to by the colors field lists contains hints for
 * each of the regions.  They are ordered according left-to-right and
 * top-to-bottom as indicated above. For each segment that is a solid
 * color the array entry will contain that color value; otherwise it
 * will contain NO_COLOR.  Segments that are completely transparent
 * will always have the value TRANSPARENT_COLOR.
 *
 * The PNG chunk type is "npTc".
 */
struct Res_png_9patch
{
    Res_png_9patch() : wasDeserialized(false), xDivs(NULL),
                       yDivs(NULL), colors(NULL) { }

    int8_t wasDeserialized;
    int8_t numXDivs;
    int8_t numYDivs;
    int8_t numColors;

    // These tell where the next section of a patch starts.
    // For example, the first patch includes the pixels from
    // 0 to xDivs[0]-1 and the second patch includes the pixels
    // from xDivs[0] to xDivs[1]-1.
    // Note: allocation/free of these pointers is left to the caller.
    int32_t* xDivs;
    int32_t* yDivs;

    int32_t paddingLeft, paddingRight;
    int32_t paddingTop, paddingBottom;

    enum {
        // The 9 patch segment is not a solid color.
        NO_COLOR = 0x00000001,

        // The 9 patch segment is completely transparent.
        TRANSPARENT_COLOR = 0x00000000
    };
    // Note: allocation/free of this pointer is left to the caller.
    uint32_t* colors;

    // Convert data from device representation to PNG file representation.
    void deviceToFile();
    // Convert data from PNG file representation to device representation.
    void fileToDevice();
    // Serialize/Marshall the patch data into a newly malloc-ed block
    void* serialize();
    // Serialize/Marshall the patch data
    void serialize(void* outData);
    // Deserialize/Unmarshall the patch data
    static Res_png_9patch* deserialize(const void* data);
    // Compute the size of the serialized data structure
    size_t serializedSize();
};
于 2011-06-28T18:08:13.457 回答
1

这是一种适用于我的解决方法。

我的应用中有默认的 9-patch 图像，用作消息气泡。我想创建可下载的内容themes，它可以更改气泡和字体颜色等其他内容。

可绘制文件夹中包含的*.9.png图像是默认的，它们包括图像周围的黑色像素：

默认传出图像 default_outgoing.9.png

“自定义”/主题气泡具有完全相同的尺寸，位置稍有变化，仍使用相同的“块”区域作为默认值，但这些不包括黑色像素或.9文件名中的 ：

粉色圆形传出图像 pink_round_outgoing.png

那么自定义一个如何工作并且仍然看起来不错呢？下面是一段获取自定义图像的代码，从默认的 9-patch 图像中获取一些值并将它们应用于自定义位图：

//Get the custom replacement image
Bitmap bitmap = BitmapFactory.decodeFile(folderpath + File.separator + "pink_round_outgoing.png");

//Get padding from the default 9-patch drawable
Drawable existingDrawable = ContextCompat.getDrawable(this, R.drawable.default_outgoing);
Rect padding = new Rect();
if (existingDrawable != null) {
    existingDrawable.getPadding(padding);
}

//Get 9-patch chunk from the default 9-patch drawable
Bitmap existingBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.default_outgoing);
byte[] chunk = existingBitmap.getNinePatchChunk();

//Finally create your custom 9-Patch drawable and set it to background
NinePatchDrawable d = new NinePatchDrawable(getResources(), bitmap, chunk, padding, null);
view.setBackground(d);
于 2019-10-24T10:35:03.237 回答