java - 如何在 Marshmallow 和 6.0 及以下版本中选择默认照片选择设置弹出窗口来打开前置摄像头

Question

当我从设置中选择打开相机拍摄个人资料照片的选项时，它在棉花糖中默认打开后置摄像头，但在棉花糖下面工作正常，所以我希望在最多棉花糖中默认打开前置摄像头

Answer 1

我使用这个代码它帮助我......

package com.oreillyschool.android2.cameraadvanced;

import java.io.IOException;

import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.hardware.Camera;
import android.hardware.Camera.PictureCallback;
import android.os.Bundle;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;

public class CameraActivity extends Activity implements PictureCallback, SurfaceHolder.Callback {

  public static final String EXTRA_CAMERA_DATA = "camera_data";

  private static final String KEY_IS_CAPTURING = "is_capturing";

  private Camera mCamera;
  private ImageView mCameraImage;
  private SurfaceView mCameraPreview;
  private Button mCaptureImageButton;
  private byte[] mCameraData;
  private boolean mIsCapturing;

  private OnClickListener mCaptureImageButtonClickListener = new OnClickListener() {
    @Override
    public void onClick(View v) {
      captureImage();
    }
  };

  private OnClickListener mRecaptureImageButtonClickListener = new OnClickListener() {
    @Override
    public void onClick(View v) {
      setupImageCapture();
    }
  };

  private OnClickListener mDoneButtonClickListener = new OnClickListener() {
    @Override
    public void onClick(View v) {
      if (mCameraData != null) {
        Intent intent = new Intent();
        intent.putExtra(EXTRA_CAMERA_DATA, mCameraData);
        setResult(RESULT_OK, intent);
      } else {
        setResult(RESULT_CANCELED);
      }
      finish();
    }
  };

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_camera);

    mCameraImage = (ImageView) findViewById(R.id.camera_image_view);
    mCameraImage.setVisibility(View.INVISIBLE);

    mCameraPreview = (SurfaceView) findViewById(R.id.preview_view);
    final SurfaceHolder surfaceHolder = mCameraPreview.getHolder();
    surfaceHolder.addCallback(this);
    surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

    mCaptureImageButton = (Button) findViewById(R.id.capture_image_button);
    mCaptureImageButton.setOnClickListener(mCaptureImageButtonClickListener);

    final Button doneButton = (Button) findViewById(R.id.done_button);
    doneButton.setOnClickListener(mDoneButtonClickListener);

    mIsCapturing = true;
  }

  @Override
  protected void onSaveInstanceState(Bundle savedInstanceState) {
    super.onSaveInstanceState(savedInstanceState);

    savedInstanceState.putBoolean(KEY_IS_CAPTURING, mIsCapturing);
  }

  @Override
  protected void onRestoreInstanceState(Bundle savedInstanceState) {
    super.onRestoreInstanceState(savedInstanceState);

    mIsCapturing = savedInstanceState.getBoolean(KEY_IS_CAPTURING, mCameraData == null);
    if (mCameraData != null) {
      setupImageDisplay();
    } else {
      setupImageCapture();
    }
  }

  @Override
  protected void onResume() {
    super.onResume();

    if (mCamera == null) {
      try {
        mCamera = Camera.open();              
        mCamera.setPreviewDisplay(mCameraPreview.getHolder());
        if (mIsCapturing) {
          mCamera.startPreview();
        }
      } catch (Exception e) {
        Toast.makeText(CameraActivity.this, "Unable to open camera.", Toast.LENGTH_LONG)
        .show();
      }
    }
  }

  @Override
  protected void onPause() {
    super.onPause();

    if (mCamera != null) {
      mCamera.release();
      mCamera = null;
    }
  }

  @Override
  public void onPictureTaken(byte[] data, Camera camera) {
    mCameraData = data;
    setupImageDisplay();
  }

  @Override
  public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
    if (mCamera != null) {
      try {
        mCamera.setPreviewDisplay(holder);
        if (mIsCapturing) {
          mCamera.startPreview();
        }
      } catch (IOException e) {
        Toast.makeText(CameraActivity.this, "Unable to start camera preview.", Toast.LENGTH_LONG).show();
      }
    }
  }

  @Override
  public void surfaceCreated(SurfaceHolder holder) {
  }

  @Override
  public void surfaceDestroyed(SurfaceHolder holder) {
  }

  private void captureImage() {
    mCamera.takePicture(null, null, this);
  }

  private void setupImageCapture() {
    mCameraImage.setVisibility(View.INVISIBLE);
    mCameraPreview.setVisibility(View.VISIBLE);
    mCamera.startPreview();
    mCaptureImageButton.setText(R.string.capture_image);
    mCaptureImageButton.setOnClickListener(mCaptureImageButtonClickListener);
  }

  private void setupImageDisplay() {
    Bitmap bitmap = BitmapFactory.decodeByteArray(mCameraData, 0, mCameraData.length);
    mCameraImage.setImageBitmap(bitmap);
    mCamera.stopPreview();
    mCameraPreview.setVisibility(View.INVISIBLE);
    mCameraImage.setVisibility(View.VISIBLE);
    mCaptureImageButton.setText(R.string.recapture_image);
    mCaptureImageButton.setOnClickListener(mRecaptureImageButtonClickListener);
  }
}