Question

我希望在自己的活动中显示前置或后置摄像头输入。另外，我希望用户控制两个摄像机的变焦。

我应该如何使用Camera对象调用，是不是已弃用？另外，如何使我的视图显示来自摄像机的实时数据？

Answer 1

您应该尝试the CameraKit library。它易于使用，并具有许多内置功能，例如：

图像和视频捕获。
自动系统权限处理。
自动预览缩放和更多。

Answer 2

首先，您需要检查设备是否支持使用多相机然后您可以使用下面的代码这是MainActivity.class

winner()

这是xml

import android.content.Context;
import android.hardware.Camera;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.widget.FrameLayout;

import java.io.IOException;

public class MainActivity extends AppCompatActivity {


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    // Create an instance of Camera
    Camera mBackCamera = getCameraInstance(0);
    // Create back camera Preview view and set it as the content of our activity.
    BackCamera mBackCam = new BackCamera(this, mBackCamera);
    FrameLayout backPreview = (FrameLayout) findViewById(R.id.back_camera_preview);
    backPreview.addView(mBackCam);

    Camera mFrontCamera = getCameraInstance(1);
    FrontCamera mFrontCam = new FrontCamera(this, mFrontCamera);
    FrameLayout frontPreview = (FrameLayout) findViewById(R.id.front_camera_preview);
    frontPreview.addView(mFrontCam);
}
public static Camera getCameraInstance(int cameraId){
    Camera c = null;
    try {
        c = Camera.open(cameraId); // attempt to get a Camera instance
    }
    catch (Exception e){
        // Camera is not available (in use or does not exist)
        Log.e("TAG","Camera " + cameraId + " not available! " + e.toString() );
    }
    return c; // returns null if camera is unavailable
}
}

class FrontCamera extends SurfaceView implements SurfaceHolder.Callback {
private SurfaceHolder mHolder;
private Camera mCamera;

public static String TAG = "FrontCamera";

public FrontCamera(Context context, Camera camera) {
    super(context);
    mCamera = camera;

    // Install a SurfaceHolder.Callback so we get notified when the
    // underlying surface is created and destroyed.
    mHolder = getHolder();
    mHolder.addCallback(this);
    // deprecated setting, but required on Android versions prior to 3.0
    mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}

public void surfaceCreated(SurfaceHolder holder) {
    // The Surface has been created, now tell the camera where to draw the preview.
    try {
        mCamera.setPreviewDisplay(holder);
        mCamera.startPreview();
    } catch (IOException e) {
        Log.d(TAG, "Error setting camera preview: " + e.getMessage());
    }
}

public void surfaceDestroyed(SurfaceHolder holder) {
    // empty. Take care of releasing the Camera preview in your activity.
}

public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
    // If your preview can change or rotate, take care of those events here.
    // Make sure to stop the preview before resizing or reformatting it.

    if (mHolder.getSurface() == null) {
        // preview surface does not exist
        return;
    }

    // stop preview before making changes
    try {
        mCamera.stopPreview();
    } catch (Exception e) {
        // ignore: tried to stop a non-existent preview
    }

    // set preview size and make any resize, rotate or
    // reformatting changes here

    // start preview with new settings
    try {
        mCamera.setPreviewDisplay(mHolder);
        mCamera.startPreview();

    } catch (Exception e) {
        Log.d(TAG, "Error starting camera : " + e.getMessage());
    }
}
}
class BackCamera extends SurfaceView implements SurfaceHolder.Callback {
    private SurfaceHolder mHolder;
    private Camera mCamera;

    public static String TAG = "BackCamera";

    public BackCamera(Context context, Camera camera) {
        super(context);
        mCamera = camera;

        // Install a SurfaceHolder.Callback so we get notified when the
        // underlying surface is created and destroyed.
        mHolder = getHolder();
        mHolder.addCallback(this);
        // deprecated setting, but required on Android versions prior to 3.0
        mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    }

    public void surfaceCreated(SurfaceHolder holder) {
        // The Surface has been created, now tell the camera where to draw the preview.
        try {
            mCamera.setPreviewDisplay(holder);
            mCamera.startPreview();
        } catch (IOException e) {
            Log.d(TAG, "Error setting camera : " + e.getMessage());
        }
    }
    public void surfaceDestroyed(SurfaceHolder holder) {
        // empty. Take care of releasing the Camera preview in your activity.
    }

    public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
        // If your preview can change or rotate, take care of those events here.
        // Make sure to stop the preview before resizing or reformatting it.

        if (mHolder.getSurface() == null) {
            // preview surface does not exist
            return;
        }

        // stop preview before making changes
        try {
            mCamera.stopPreview();
        } catch (Exception e) {
            // ignore: tried to stop a non-existent preview
        }

        // set preview size and make any resize, rotate or
        // reformatting changes here

        // start preview with new settings
        try {
            mCamera.setPreviewDisplay(mHolder);
            mCamera.startPreview();

        } catch (Exception e) {
            Log.d(TAG, "Error starting camera : " + e.getMessage());
        }
    }
}

放大显示前后摄像头

2 个答案: