我开发一个应用程序，它可以帮助用户捕捉到的android屏幕快照（安卓4.x版）。我知道，帧缓冲区在Android ICS打破。我听说，我们可以使用ScreenShotClient要做到这一点，如下。

I am developing an application which helps user to capture android screen shot (Android 4.x) . I know that framebuffer is broken on android ICS. I hear that we can use ScreenShotClient to do this as below.

ScreenshotClient screenshotClient = new ScreenshotClient();
screenshotClient->update();

不过，我有什么库导入使用它？它是可用下JNI code使用？

But, what library I have to import to use it? Is it available to use under jni code?

推荐答案

您所需要的库称为 libsurfaceflinger_client.so 。你可以从任何设备上运行姜饼或更高 Android版本，使用命令将其

The library you need is called libsurfaceflinger_client.so. You can pull it from any device running Gingerbread or higher version of Android, with command

adb pull /system/lib/libsurfaceflinger_client.so

在ICS或JB，类 ScreenshotClient 是 libgui.so 的一部分。在生成文件screencap这是一个使用的例子 ScreenshotClient ，表明连接器可能需要其他库：

On ICS or JB, class ScreenshotClient is part of libgui.so. The makefile for screencap which is the example of using ScreenshotClient, suggests that linker may need other libraries:

libcutils libutils libbinder libskia libui libgui

此外， screencap.cpp 的code的情况如下：

Also, the code of screencap.cpp goes as follows:

ScreenshotClient screenshot;
if (screenshot.update() == NO_ERROR) {
    base = screenshot.getPixels();
    w = screenshot.getWidth();
    h = screenshot.getHeight();
    f = screenshot.getFormat();
    size = screenshot.getSize();
} else {
    const char* fbpath = "/dev/graphics/fb0";
    int fb = open(fbpath, O_RDONLY);
    if (fb >= 0) {
        struct fb_var_screeninfo vinfo;
        if (ioctl(fb, FBIOGET_VSCREENINFO, &vinfo) == 0) {
...

这意味着，至少你必须检查更新（）取得成功。不幸的是，除非德设备植根，该应用程序不能被授予许可的/ dev /图形/ FB0阅读和使用 /系统的回退/斌/ screencap 或 /系统/斌/截图。

This means that at least you must check that update() succeed. Unfortunately, unless teh device is rooted, the apps cannot be granted permission to read from /dev/graphics/fb0 and use the fallback of /system/bin/screencap or /system/bin/screenshot.