使用createcapturesession(SessionConfiguration)创建捕获会话

最近在学习camera2的时候发现原本的

createCaptureSession(@NonNull List outputs,
@NonNull CameraCaptureSession.StateCallback callback, @Nullable Handler handler)

    @Deprecated
    public abstract void createCaptureSession(@NonNull List<Surface> outputs,
            @NonNull CameraCaptureSession.StateCallback callback, @Nullable Handler handler)
            throws CameraAccessException;

已不推荐使用，android开发者文档那边也没有更新，因此写一篇博客记录一下新的方法

public void createCaptureSession(
            SessionConfiguration config) throws CameraAccessException {
        throw new UnsupportedOperationException("No default implementation");
    }

让我们先看一下SessionConfiguration的源码

    /**
     * Create a new {@link SessionConfiguration}.
     *
     * @param sessionType The session type.
     * @param outputs A list of output configurations for the capture session.
     * @param executor The executor which should be used to invoke the callback. In general it is
     *                 recommended that camera operations are not done on the main (UI) thread.
     * @param cb A state callback interface implementation.
     *
     * @see #SESSION_REGULAR
     * @see #SESSION_HIGH_SPEED
     * @see CameraDevice#createCaptureSession(List, CameraCaptureSession.StateCallback, Handler)
     * @see CameraDevice#createCaptureSessionByOutputConfigurations
     * @see CameraDevice#createReprocessableCaptureSession
     * @see CameraDevice#createConstrainedHighSpeedCaptureSession
     */
    public SessionConfiguration(@SessionMode int sessionType,
            @NonNull List<OutputConfiguration> outputs,
            @NonNull @CallbackExecutor Executor executor,
            @NonNull CameraCaptureSession.StateCallback cb) {
        mSessionType = sessionType;
        mOutputConfigurations = Collections.unmodifiableList(new ArrayList<>(outputs));
        mStateCallback = cb;
        mExecutor = executor;
    }

是不是很熟悉，没错，output是输出流，也就是我们以前所使用的surface output；cb则是状态回调借口，也就是我们以前的callback；executor则是应用于执行回调的执行器，用于执行Intent的工作，我们再看源码。

public interface Executor {

    /**
     * Executes the given command at some time in the future.  The command
     * may execute in a new thread, in a pooled thread, or in the calling
     * thread, at the discretion of the {@code Executor} implementation.
     *
     * @param command the runnable task
     * @throws RejectedExecutionException if this task cannot be
     * accepted for execution
     * @throws NullPointerException if command is null
     */
    void execute(Runnable command);
}

就是一个执行命令的线程而已。

最后附上我自己的代码，希望对大家能有所帮助。

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
                    cameraDevice.createCaptureSession(new SessionConfiguration(
                            SessionConfiguration.SESSION_REGULAR, outputs,
                            new Executor() {
                                @Override
                                public void execute(Runnable command) {
                                    command.run();
                                }
                            },
                            new CameraCaptureSession.StateCallback() {
                                @Override
                                public void onConfigured(@NonNull CameraCaptureSession session) {
                                    cameraCaptureSession = session;
                                    Log.i(TAG, "onConfigured: ====>CreateCameraCaptureSession Successful");

                                    try {
                                        builder = cameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
                                        builder.addTarget(mySurface);
                                        cameraCaptureSession.setRepeatingRequest(builder.build(), null, null);
                                    } catch (Exception e) {
                                        e.printStackTrace();
                                    }
                                }

                                @Override
                                public void onConfigureFailed(@NonNull CameraCaptureSession session) {
                                    Log.e(TAG, "onConfigureFailed: ====>Create CameraCaptureSession Failed");
                                }
                            }));
                }