java - Android 问题中的自定义相机应用程序 - 旋转 270、拉伸(stretch)捕获 View 且未获得所有功能

Question

我从代码https://github.com/josnidhin/Android-Camera-Example 得到了帮助

但面临一些问题，例如:

1. 如何添加自动对焦和闪光灯功能。 - 在最后编辑的代码中解决
2. 当屏幕方向为 270 度时，真实 View 显示旋转 180 度。
3. 捕获 View 显示拉伸(stretch)。

我调用自定义相机类的CODE

    Camera cam = Camera.open();
    if (null == cam) 
    {
        // no camera exists
        Intent i = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
        startActivityForResult(i, RESULT_LOAD_IMAGE);
    } 
    else 
    {
        cam.release();
        Intent intent = new Intent(CreateList.this, CamTestActivity.class);
        startActivityForResult(intent, TAKE_PICTURE);
    }

自定义相机类CamTestActivity.class

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.hardware.Camera;
import android.hardware.Camera.AutoFocusCallback;
import android.hardware.Camera.PictureCallback;
import android.hardware.Camera.ShutterCallback;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.view.SurfaceView;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnLongClickListener;
import android.view.ViewGroup.LayoutParams;
import android.view.Window;
import android.view.WindowManager;
import android.widget.Button;
import android.widget.FrameLayout;

import com.example.R;

public class CamTestActivity extends Activity {
    private static final String TAG = "CamTestActivity";
    Preview preview;
    Button buttonClick, buttonCancel;
    Camera camera;
    String fileName;
    Activity act;
    Context ctx;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        ctx = this;
        act = this;
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);

        setContentView(R.layout.take_picture);

        preview = new Preview(this, (SurfaceView) findViewById(R.id.surfaceView));
        preview.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));
        ((FrameLayout) findViewById(R.id.preview)).addView(preview);
        preview.setKeepScreenOn(true);

        buttonClick = (Button) findViewById(R.id.buttonClick);
        buttonCancel = (Button) findViewById(R.id.buttonCancel);

        buttonClick.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                camera.takePicture(shutterCallback, rawCallback, jpegCallback);
            }
        });

        buttonClick.setOnLongClickListener(new OnLongClickListener() {
            @Override
            public boolean onLongClick(View arg0) {
                camera.autoFocus(new AutoFocusCallback() {
                    @Override
                    public void onAutoFocus(boolean focus_flag, Camera cam) {
                        if (focus_flag)
                            cam.takePicture(shutterCallback, rawCallback, jpegCallback);
                    }
                });
                return true;
            }
        });

        buttonCancel.setOnClickListener(new OnClickListener() {
            public void onClick(View v)     {
                finish();
            }
        });
    }

    @Override
    protected void onResume() {
        super.onResume();
        // preview.camera = Camera.open();
        camera = Camera.open(0);
        camera.startPreview();
        preview.setCamera(camera);
    }

    @Override
    protected void onPause() {
        if (camera != null)     {
            camera.stopPreview();
            preview.setCamera(null);
            camera.release();
            camera = null;
        }
        super.onPause();
    }

    private void resetCam() {
        camera.startPreview();
        preview.setCamera(camera);

        Intent i = new Intent();
        i.putExtra("captured_img", fileName);
        setResult(RESULT_OK, i);
        finish();
    }

    ShutterCallback shutterCallback = new ShutterCallback()     {
        public void onShutter() {
            // Log.d(TAG, "onShutter'd");
        }
    };

    PictureCallback rawCallback = new PictureCallback()     {
        public void onPictureTaken(byte[] data, Camera camera) {
            // Log.d(TAG, "onPictureTaken - raw");
        }
    };

    PictureCallback jpegCallback = new PictureCallback() {
        public void onPictureTaken(byte[] data, Camera camera) {
            FileOutputStream outStream = null;
            try     {
                // Write to SD Card
                fileName = String.format(Environment.getExternalStorageDirectory() + "/FansRave_UploadDeal_Pic.jpg");

                outStream = new FileOutputStream(fileName);
                outStream.write(data);
                outStream.close();
                Log.d(TAG, "onPictureTaken - wrote bytes: " + data.length);

                resetCam();
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            } 
            Log.d(TAG, "onPictureTaken - jpeg");
        }
    };
}

Preview.class

import java.io.IOException;
import java.util.List;

import android.content.Context;
import android.content.pm.PackageManager;
import android.content.res.Configuration;
import android.hardware.Camera;
import android.hardware.Camera.Parameters;
import android.hardware.Camera.Size;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.ViewGroup;

class Preview extends ViewGroup implements SurfaceHolder.Callback {
    private final String TAG = "Preview";

    SurfaceView mSurfaceView;
    SurfaceHolder mHolder;
    Size mPreviewSize;
    List<Size> mSupportedPreviewSizes;
    Camera mCamera;
    Context mContext;

    Preview(Context context, SurfaceView sv) {
        super(context);

        mContext = context;
        mSurfaceView = sv;

        mHolder = mSurfaceView.getHolder();
        mHolder.addCallback(this);
        mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    }

    public void setCamera(Camera camera) {
        mCamera = camera;
        if (mCamera != null) {
            mSupportedPreviewSizes = mCamera.getParameters().getSupportedPreviewSizes();
            requestLayout();

            // get Camera parameters
            Camera.Parameters params = mCamera.getParameters();

            List<String> focusModes = params.getSupportedFocusModes();
            if (focusModes.contains(Camera.Parameters.FOCUS_MODE_AUTO)) {
                // set the focus mode
                params.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
                // set Camera parameters
                mCamera.setParameters(params);
            }
        }
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        // We purposely disregard child measurements because act as a
        // wrapper to a SurfaceView that center the camera preview instead
        // of stretching it.

        final int width = resolveSize(getSuggestedMinimumWidth(), widthMeasureSpec);
        final int height = resolveSize(getSuggestedMinimumHeight(), heightMeasureSpec);
        setMeasuredDimension(width, height);

        if (mSupportedPreviewSizes != null) {
            mPreviewSize = getOptimalPreviewSize(mSupportedPreviewSizes, width, height);
        }
    }

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        if (changed && getChildCount() > 0) {
            final View child = getChildAt(0);

            final int width = r - l;
            final int height = b - t;

            int previewWidth = width;
            int previewHeight = height;

            if (mPreviewSize != null) {
                previewWidth = mPreviewSize.width;
                previewHeight = mPreviewSize.height;
            }

            // Center the child SurfaceView within the parent.
            if (width * previewHeight > height * previewWidth) {
                final int scaledChildWidth = previewWidth * height / previewHeight;
                child.layout((width - scaledChildWidth) / 2, 0, (width + scaledChildWidth) / 2, height);
            } else {
                final int scaledChildHeight = previewHeight * width / previewWidth;
                child.layout(0, (height - scaledChildHeight) / 2, width, (height + scaledChildHeight) / 2);
            }
        }
    }

    public void surfaceCreated(SurfaceHolder holder) {
        // The Surface has been created, acquire the camera and tell it where to draw.
        try {
            if (mCamera != null) {
                if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE) {
                    Global.orientation = "LANDSCAPE";
                    Log.e("Orientation mode", "" + Global.orientation);
                } else if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT)     {
                    mCamera.stopPreview();
                    mCamera.setDisplayOrientation(90);
                    mCamera.startPreview();
                    Global.orientation = "PORTRAIT";
                    Log.e("Orientation mode", "" + Global.orientation);
                }
                mCamera.setPreviewDisplay(holder);
            }
        } catch (IOException exception) {
            Log.e(TAG, "IOException caused by setPreviewDisplay()", exception);
            mCamera.release();
            mCamera = null;
        }
    }

    public void surfaceDestroyed(SurfaceHolder holder) {
        // Surface will be destroyed when we return, so stop the preview.
        if (mCamera != null) {
            mCamera.stopPreview();
            mCamera.setPreviewCallback(null);
            mCamera.release();
            mCamera = null;
        }
    }

    private Size getOptimalPreviewSize(List<Size> sizes, int w, int h) {
        final double ASPECT_TOLERANCE = 0.2;
        double targetRatio = (double) w / h;
        if (sizes == null) return null;

        Size optimalSize = null;
        double minDiff = Double.MAX_VALUE;

        int targetHeight = h;

        // Try to find an size match aspect ratio and size
        for (Size size : sizes) {
            double ratio = (double) size.width / size.height;
            if (Math.abs(ratio - targetRatio) > ASPECT_TOLERANCE) continue;
            if (Math.abs(size.height - targetHeight) < minDiff) {
                optimalSize = size;
                minDiff = Math.abs(size.height - targetHeight);
            }
        }

        // Cannot find the one match the aspect ratio, ignore the requirement
        if (optimalSize == null) {
            minDiff = Double.MAX_VALUE;
            for (Size size : sizes) {
                if (Math.abs(size.height - targetHeight) < minDiff) {
                    optimalSize = size;
                    minDiff = Math.abs(size.height - targetHeight);
                }
            }
        }
        return optimalSize;
    }

    public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
        if (mCamera != null) {
            Camera.Parameters parameters = mCamera.getParameters();
            parameters.setPreviewSize(mPreviewSize.width, mPreviewSize.height);

            // for flash
            if (mContext.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA_FLASH))
                parameters.setFlashMode(Parameters.FLASH_MODE_AUTO);

            requestLayout();

            mCamera.setParameters(parameters);
            mCamera.startPreview();

            mCamera.autoFocus(null);
        }
    }
}

XML 文件 take_picture.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/layout"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >

<FrameLayout
    android:id="@+id/preview"
    android:layout_width="fill_parent"
    android:layout_height="0dp"
    android:layout_weight="1" >

    <SurfaceView
        android:id="@+id/surfaceView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <RelativeLayout
        android:layout_width="wrap_content"
        android:layout_height="fill_parent"
        android:orientation="vertical" >

        <Button
            android:id="@+id/buttonClick"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerHorizontal="true"
            android:layout_centerVertical="true"
            android:background="@drawable/button_gradient" />

        <Button
            android:id="@+id/buttonCancel"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentBottom="true"
            android:layout_alignParentLeft="true"
            android:text="Cancel" />
    </RelativeLayout>
</FrameLayout>

</LinearLayout>

Answer 1

如果您在使用自定义相机时遇到问题，请使用带有以下代码的 Intent 相机，以便可以旋转图像

    Bitmap bm = BitmapFactory.decodeStream(new FileInputStream(mFile), null, mBitmapFactoryOptions);
            Bitmap bitmap = bm;

            ExifInterface exif = new ExifInterface(ImagePath);

            int orientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, 1);

            Log.e("ExifInteface .........", "rotation =" + orientation);

            // exif.setAttribute(ExifInterface.ORIENTATION_ROTATE_90, 90);

            Log.e("orientation", "" + orientation);
            Matrix m = new Matrix();

            if ((orientation == ExifInterface.ORIENTATION_ROTATE_180)) {
                m.postRotate(180);
                // m.postScale((float) bm.getWidth(), (float)
                // bm.getHeight());
                // if(m.preRotate(90)){
                Log.e("in orientation", "" + orientation);
                bitmap = Bitmap.createBitmap(bm, 0, 0, bm.getWidth(), bm.getHeight(), m, true);
                return bitmap;
            } else if (orientation == ExifInterface.ORIENTATION_ROTATE_90) {
                m.postRotate(90);
                Log.e("in orientation", "" + orientation);
                bitmap = Bitmap.createBitmap(bm, 0, 0, bm.getWidth(), bm.getHeight(), m, true);
                return bitmap;
            } else if (orientation == ExifInterface.ORIENTATION_ROTATE_270) {
                m.postRotate(270);
                Log.e("in orientation", "" + orientation);
                bitmap = Bitmap.createBitmap(bm, 0, 0, bm.getWidth(), bm.getHeight(), m, true);
                return bitmap;

            }