android截屏代码：C++实现

来源：互联网发布：云点域名编辑：程序博客网时间：2024/05/29 15:28

示例代码在:

frameworks\base\services\surfaceflinger\tests\screencap\screencap.cpp

/* * Copyright (C) 2010 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * *      http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include <utils/Log.h> #include <binder/IPCThreadState.h> #include <binder/ProcessState.h> #include <binder/IServiceManager.h> #include <binder/IMemory.h> #include <surfaceflinger/ISurfaceComposer.h> #include <SkImageEncoder.h> #include <SkBitmap.h> using namespace android; int main(int argc, char** argv) { if (argc != 2) { printf("usage: %s path\n", argv[0]); exit(0); } const String16 name("SurfaceFlinger"); sp<ISurfaceComposer> composer; getService(name, &composer); getService(name, &composer); sp<IMemoryHeap> heap; uint32_t w, h; PixelFormat f; status_t err = composer->captureScreen(0, &heap, &w, &h, &f, 0, 0); if (err != NO_ERROR) { fprintf(stderr, "screen capture failed: %s\n", strerror(-err)); exit(0); } printf("screen capture success: w=%u, h=%u, pixels=%p\n", w, h, heap->getBase()); printf("saving file as PNG in %s ...\n", argv[1]); SkBitmap b; b.setConfig(SkBitmap::kARGB_8888_Config, w, h); b.setPixels(heap->getBase()); SkImageEncoder::EncodeFile(argv[1], b, SkImageEncoder::kPNG_Type, SkImageEncoder::kDefaultQuality); return 0; }

编译后生成/system/bin/test-screencap
测试时终端输入test-screencap /mnt/sdcard/scapxx.png
可以看到SD卡生成截屏文件scapxx.png，默认大小为屏幕分辨率
如果想把这个功能写到自己的应用里
写个JNI，参考上面代码即可，但记得权限声明
<span style="font-size:24px;"><uses-permission android:name="android.permission.READ_FRAME_BUFFER"
/></span>
当然最好是系统级实现，响应某个组合键来截屏，像Android4.0

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