Android O和Android P在绘制界面时默认使用的是不同的库进行绘制的

• Android O是通过使用opengl进行绘制

  • frameworks/base/libs/hwui/Properties.cpp

  RenderPipelineType Properties::getRenderPipelineType() {
      if (sRenderPipelineType != RenderPipelineType::NotInitialized) {
          return sRenderPipelineType;
      }
      char prop[PROPERTY_VALUE_MAX];
      property_get(PROPERTY_RENDERER, prop, "opengl");
      if (!strcmp(prop, "skiagl")) {
          ALOGD("Skia GL Pipeline");
          sRenderPipelineType = RenderPipelineType::SkiaGL;
      } else if (!strcmp(prop, "skiavk")) {
          ALOGD("Skia Vulkan Pipeline");
          sRenderPipelineType = RenderPipelineType::SkiaVulkan;
      } else {  //"opengl"
          ALOGD("HWUI GL Pipeline");
          sRenderPipelineType = RenderPipelineType::OpenGL;
      }
      return sRenderPipelineType;
  }
  

• Android P是通过使用skiagl进行绘制

  • frameworks/base/libs/hwui/Properties.cpp

  RenderPipelineType Properties::getRenderPipelineType() {
      if (sRenderPipelineType != RenderPipelineType::NotInitialized) {
          return sRenderPipelineType;
      }
      char prop[PROPERTY_VALUE_MAX];
      property_get(PROPERTY_RENDERER, prop, "skiagl");
      if (!strcmp(prop, "skiagl")) {
          ALOGD("Skia GL Pipeline");
          sRenderPipelineType = RenderPipelineType::SkiaGL;
      } else if (!strcmp(prop, "skiavk")) {
          ALOGD("Skia Vulkan Pipeline");
          sRenderPipelineType = RenderPipelineType::SkiaVulkan;
      } else {  //"opengl"
          ALOGD("HWUI GL Pipeline");
          sRenderPipelineType = RenderPipelineType::OpenGL;
      }
      return sRenderPipelineType;
  }
  

• Android在9.0后的版本中默认使用skiagl替换