高通android9.0双屏显示，主屏设置开机默认为横屏，而副屏的方向没有跟随选择，并且没全屏显示的问题

在高通android9.0的平台上，有一个项目是有双屏显示的，需要将机器设置为开机默认横屏显示，主屏设置开机默认为横屏后，而副屏的方向没有跟随选择，并且没全屏显示的问题，当主屏的activity如果固定为竖屏的情况下，而副屏显示是正常的。

这个问题主要是代码中做了配置，只需要在system.prop中添加persist.demo.hdmirotates=true的配置副屏即可跟随主屏的显示方向显示。这个配置是在frameworks/base/services/core/java/com/android/server/display/LocalDisplayAdapter.java中，主要代码如下，如需再调整副屏的方向可在以下方法中修改mInfo.rotation的值即可

public DisplayDeviceInfo getDisplayDeviceInfoLocked() {
            if (mInfo == null) {
                SurfaceControl.PhysicalDisplayInfo phys = mDisplayInfos[mActivePhysIndex];
                mInfo = new DisplayDeviceInfo();
                mInfo.width = phys.width;
                mInfo.height = phys.height;
                mInfo.modeId = mActiveModeId;
                mInfo.defaultModeId = mDefaultModeId;
                mInfo.supportedModes = new Display.Mode[mSupportedModes.size()];
                for (int i = 0; i < mSupportedModes.size(); i++) {
                    DisplayModeRecord record = mSupportedModes.valueAt(i);
                    mInfo.supportedModes[i] = record.mMode;
                }
                mInfo.colorMode = mActiveColorMode;
                mInfo.supportedColorModes =
                        new int[mSupportedColorModes.size()];
                for (int i = 0; i < mSupportedColorModes.size(); i++) {
                    mInfo.supportedColorModes[i] = mSupportedColorModes.get(i);
                }
                mInfo.hdrCapabilities = mHdrCapabilities;
                mInfo.appVsyncOffsetNanos = phys.appVsyncOffsetNanos;
                mInfo.presentationDeadlineNanos = phys.presentationDeadlineNanos;
                mInfo.state = mState;
                mInfo.uniqueId = getUniqueId();

                // Assume that all built-in displays that have secure output (eg. HDCP) also
                // support compositing from gralloc protected buffers.
                if (phys.secure) {
                    mInfo.flags = DisplayDeviceInfo.FLAG_SECURE
                            | DisplayDeviceInfo.FLAG_SUPPORTS_PROTECTED_BUFFERS;
                }

                final Resources res = getOverlayContext().getResources();
                if (mBuiltInDisplayId == SurfaceControl.BUILT_IN_DISPLAY_ID_MAIN) {
                    mInfo.name = res.getString(
                            com.android.internal.R.string.display_manager_built_in_display_name);
                    mInfo.flags |= DisplayDeviceInfo.FLAG_DEFAULT_DISPLAY
                            | DisplayDeviceInfo.FLAG_ROTATES_WITH_CONTENT;
                    if (res.getBoolean(com.android.internal.R.bool.config_mainBuiltInDisplayIsRound)
                            || (Build.IS_EMULATOR
                            && SystemProperties.getBoolean(PROPERTY_EMULATOR_CIRCULAR, false))) {
                        mInfo.flags |= DisplayDeviceInfo.FLAG_ROUND;
                    }
                    mInfo.displayCutout = DisplayCutout.fromResources(res, mInfo.width,
                            mInfo.height);
                    mInfo.type = Display.TYPE_BUILT_IN;
                    mInfo.densityDpi = (int)(phys.density * 160 + 0.5f);
                    mInfo.xDpi = phys.xDpi;
                    mInfo.yDpi = phys.yDpi;
                    mInfo.touch = DisplayDeviceInfo.TOUCH_INTERNAL;
                } else if (mBuiltInDisplayId >= SurfaceControl.BUILT_IN_DISPLAY_ID_HDMI &&
                           mBuiltInDisplayId < SurfaceControl.BUILT_IN_DISPLAY_ID_EXT_MIN) {
                    mInfo.displayCutout = null;
                    mInfo.type = Display.TYPE_HDMI;
                    mInfo.flags |= DisplayDeviceInfo.FLAG_PRESENTATION;
                    mInfo.name = getContext().getResources().getString(
                            com.android.internal.R.string.display_manager_hdmi_display_name);
                    mInfo.touch = DisplayDeviceInfo.TOUCH_EXTERNAL;
                    mInfo.setAssumedDensityForExternalDisplay(phys.width, phys.height);

                    // For demonstration purposes, allow rotation of the external display.
                    // In the future we might allow the user to configure this directly.
                    if ("portrait".equals(SystemProperties.get("persist.demo.hdmirotation"))) {
                        mInfo.rotation = Surface.ROTATION_270;
                    }

                    // For demonstration purposes, allow rotation of the external display
                    // to follow the built-in display.
                    if (SystemProperties.getBoolean("persist.demo.hdmirotates", false)) {
                        mInfo.flags |= DisplayDeviceInfo.FLAG_ROTATES_WITH_CONTENT;
                        //mInfo.rotation = Surface.ROTATION_180;//自己所需要的方向
                    }

                    if (!res.getBoolean(
                                com.android.internal.R.bool.config_localDisplaysMirrorContent)) {
                        mInfo.flags |= DisplayDeviceInfo.FLAG_OWN_CONTENT_ONLY;
                    }

                    if (res.getBoolean(com.android.internal.R.bool.config_localDisplaysPrivate)) {
                        mInfo.flags |= DisplayDeviceInfo.FLAG_PRIVATE;
                    }
                } else {
                    mInfo.type = Display.TYPE_BUILT_IN;
                    mInfo.touch = DisplayDeviceInfo.TOUCH_INTERNAL;
                    mInfo.name = getContext().getResources().getString(
                            com.android.internal.R.string.display_manager_built_in_display_name);
                    mInfo.flags |= DisplayDeviceInfo.FLAG_ROTATES_WITH_CONTENT;

                    if (SystemProperties.getBoolean(
                                    "vendor.display.builtin_presentation", false)) {
                        mInfo.flags |= DisplayDeviceInfo.FLAG_PRESENTATION;
                    } else {
                        mInfo.flags |= DisplayDeviceInfo.FLAG_PRIVATE;
                    }

                    if (!SystemProperties.getBoolean(
                                    "vendor.display.builtin_mirroring", false)) {
                        mInfo.flags |= DisplayDeviceInfo.FLAG_OWN_CONTENT_ONLY;
                    }

                    mInfo.setAssumedDensityForExternalDisplay(phys.width, phys.height);
                }
            }
            return mInfo;
        }

如需设置副屏的显示方向为固定某个方向可参考https://blog.csdn.net/kris_fei/article/details/86598923