Android使用C++截屏并显示

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　　使用android底层自带的截屏源码进行修改后，将截取屏幕的内容再次显示在屏幕上，使屏幕呈现出暂停的效果。

　　android自带的截屏代码在android\JB\frameworks\base\cmds\screencap\screencap.cpp文件中，我是参考这个进行修改的，代码如下：

 1 int main(int argc, char** argv)  
 2 {  
 3 
 4     sp<ProcessState> proc(ProcessState::self());  
 5     // create a client to surfaceflinger  
 6     sp<SurfaceComposerClient> client = new SurfaceComposerClient();  //创建SurfaceFlinger的本地代理
 7     char str[80];
 8     DisplayInfo display;  
 9     //获取屏幕的宽高等信息
10     client->getDisplayInfo(client->getBuiltInDisplay(HWC_DISPLAY_PRIMARY), &display); 
11  
12     //创建SurfaceControl的本地代理
13     sp<SurfaceControl> surfaceControl = client->createSurface(String8("testsurface"), 
14         1920/*240*/, 1080/*160*/, PIXEL_FORMAT_RGBA_8888, 0);  
15                        
16     /*********************************************************************/
17     SurfaceComposerClient::openGlobalTransaction();  
18     surfaceControl->setLayer(120000); //设置z轴     
19     surfaceControl->setSize(display.w, display.h);  
20     surfaceControl->setPosition(0, 0);  //起始位置 
21     SurfaceComposerClient::closeGlobalTransaction();
22     // 获取Surface本地代理
23     sp<Surface> surface = surfaceControl->getSurface();//获取surface
24     Surface::SurfaceInfo info;  
25     
26     //创建SurfaceControl的本地代理
27     sp<SurfaceControl> surfaceControl1 = client->createSurface(String8("wenfu"), 
28         display.w, display.h, PIXEL_FORMAT_RGBA_8888, 0);  
29     SurfaceComposerClient::openGlobalTransaction();  
30     surfaceControl1->setLayer(110000); //设置z轴     
31     surfaceControl1->setSize(display.w, display.h);  
32     surfaceControl1->setPosition(0, 0);  //起始位置 
33     SurfaceComposerClient::closeGlobalTransaction();
34     // 获取Surface本地代理
35     sp<Surface> surface1 = surfaceControl1->getSurface();//获取surface
36     Surface::SurfaceInfo info1;  
37     
38     ssize_t bpr ;
39     SkBitmap bitmap;         
40     SkCanvas canvas ;
41     SkCanvas canvas1;
42     SkBitmap bitmap1; 
43     SkPath path;
44     SkPaint paint;  //paint可以指定绘图的颜色，文本的大小及对齐方式，编码格式
45 
46     int sx,sy;
47     int w,h;
48     int flg = 1;
49     int flg2 = 0;
50     int lastx = 0, lasty = 0, ctrx = 0, ctry = 0;
51     char st[30];
52 /////////////////////////////////////////////////////////////////////////////////////////    
53     void const* mapbase = MAP_FAILED;
54     ssize_t mapsize = -1;
55     void const* base = 0;
56     size_t size = 0;
57     int ww,hh;
58     ScreenshotClient screenshot; //下面是截屏操作
59     sp<IBinder> display1 = SurfaceComposerClient::getBuiltInDisplay(ISurfaceComposer::eDisplayIdMain);
60     if (display1 != NULL && screenshot.update(display1) == NO_ERROR) 
61     {
62         base = screenshot.getPixels();
63         ww = screenshot.getWidth();
64         hh = screenshot.getHeight();
65         size = screenshot.getSize();
66     }
67     
68     if (base)  //以下是显示部分
69     {
70         SkBitmap bitm;
71         bitm.setConfig(SkBitmap::kARGB_8888_Config, ww, hh);
72         bitm.setPixels((void*)base);
73         surface1->lock(&info1);  
74             bpr = info1.s * bytesPerPixel(info1.format);  
75             bitmap1.setConfig(SkBitmap::kARGB_8888_Config, display.w, display.h, bpr);  
76             bitmap1.setPixels(info1.bits);
77             canvas1.setDevice(new SkDevice(bitmap1));    
78             canvas1.drawBitmap(bitm, SkIntToScalar(0), SkIntToScalar(0));  //从0，0点开始画图
79         surface1->unlockAndPost();       
80     }
81     if (mapbase != MAP_FAILED) {
82         munmap((void *)mapbase, mapsize);
83     }
84     ////////////////////////////////////////////////////////////////////////////////////////
85     
86     while(1)；
87     
88     return 0;  
89 }