问题
I using code Camera2 API at: https://github.com/googlesamples/android-Camera2Basic.
If i take picture time 1: afState =4, it is take picture ok.
But if I take picture time 2: afState=1, it can't take picture.
My Phone: Using android 7.0
private fun capturePicture(result: CaptureResult) {
val afState = result.get(CaptureResult.CONTROL_AF_STATE)
if (afState == null) {
captureStillPicture()
} else if (afState == CaptureResult.CONTROL_AF_STATE_FOCUSED_LOCKED
|| afState == CaptureResult.CONTROL_AF_STATE_NOT_FOCUSED_LOCKED) {
// CONTROL_AE_STATE can be null on some devices
val aeState = result.get(CaptureResult.CONTROL_AE_STATE)
if (aeState == null || aeState == CaptureResult.CONTROL_AE_STATE_CONVERGED) {
state = STATE_PICTURE_TAKEN
captureStillPicture()
} else {
runPrecaptureSequence()
}
}
}
Why Camera2 API working not correct?
回答1:
THE FOLLOWING STEPS ARE TAKEN WHEN USING ANDROID CAMERA2 API
**Open the Manifest.xml **
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.inducesmile.androidcameraapi2">
<uses-sdk
android:minSdkVersion="21"
android:targetSdkVersion="21" />
<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-feature android:name="android.hardware.camera2.full" />
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".AndroidCameraApi">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
Open the main layout xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context="com.inducesmile.androidcameraapi2.AndroidCameraApi">
<TextureView
android:id="@+id/texture"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_above="@+id/btn_takepicture"
android:layout_alignParentTop="true"/>
<Button
android:id="@+id/btn_takepicture"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginBottom="16dp"
android:layout_marginTop="16dp"
android:text="@string/take_picture" />
</RelativeLayout>
Open Main java class
import android.Manifest;
import android.content.Context;
import android.content.pm.PackageManager;
import android.graphics.ImageFormat;
import android.graphics.SurfaceTexture;
import android.hardware.camera2.CameraAccessException;
import android.hardware.camera2.CameraCaptureSession;
import android.hardware.camera2.CameraCharacteristics;
import android.hardware.camera2.CameraDevice;
import android.hardware.camera2.CameraManager;
import android.hardware.camera2.CameraMetadata;
import android.hardware.camera2.CaptureRequest;
import android.hardware.camera2.TotalCaptureResult;
import android.hardware.camera2.params.StreamConfigurationMap;
import android.media.Image;
import android.media.ImageReader;
import android.os.Bundle;
import android.os.Environment;
import android.os.Handler;
import android.os.HandlerThread;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.util.Size;
import android.util.SparseIntArray;
import android.view.Surface;
import android.view.TextureView;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
public class AndroidCameraApi extends AppCompatActivity {
private static final String TAG = "AndroidCameraApi";
private Button takePictureButton;
private TextureView textureView;
private static final SparseIntArray ORIENTATIONS = new SparseIntArray();
static {
ORIENTATIONS.append(Surface.ROTATION_0, 90);
ORIENTATIONS.append(Surface.ROTATION_90, 0);
ORIENTATIONS.append(Surface.ROTATION_180, 270);
ORIENTATIONS.append(Surface.ROTATION_270, 180);
}
private String cameraId;
protected CameraDevice cameraDevice;
protected CameraCaptureSession cameraCaptureSessions;
protected CaptureRequest captureRequest;
protected CaptureRequest.Builder captureRequestBuilder;
private Size imageDimension;
private ImageReader imageReader;
private File file;
private static final int REQUEST_CAMERA_PERMISSION = 200;
private boolean mFlashSupported;
private Handler mBackgroundHandler;
private HandlerThread mBackgroundThread;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_android_camera_api);
textureView = (TextureView) findViewById(R.id.texture);
assert textureView != null;
textureView.setSurfaceTextureListener(textureListener);
takePictureButton = (Button) findViewById(R.id.btn_takepicture);
assert takePictureButton != null;
takePictureButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
takePicture();
}
});
}
TextureView.SurfaceTextureListener textureListener = new
TextureView.SurfaceTextureListener() {
@Override
public void onSurfaceTextureAvailable(SurfaceTexture surface, int width,
int height) {
//open your camera here
openCamera();
}
@Override
public void onSurfaceTextureSizeChanged(SurfaceTexture surface, int
width, int height) {
// Transform you image captured size according to the surface width
and height
}
@Override
public boolean onSurfaceTextureDestroyed(SurfaceTexture surface) {
return false;
}
@Override
public void onSurfaceTextureUpdated(SurfaceTexture surface) {
}
};
private final CameraDevice.StateCallback stateCallback = new
CameraDevice.StateCallback() {
@Override
public void onOpened(CameraDevice camera) {
//This is called when the camera is open
Log.e(TAG, "onOpened");
cameraDevice = camera;
createCameraPreview();
}
@Override
public void onDisconnected(CameraDevice camera) {
cameraDevice.close();
}
@Override
public void onError(CameraDevice camera, int error) {
cameraDevice.close();
cameraDevice = null;
}
};
final CameraCaptureSession.CaptureCallback captureCallbackListener = new CameraCaptureSession.CaptureCallback() {
@Override
public void onCaptureCompleted(CameraCaptureSession session, CaptureRequest request, TotalCaptureResult result) {
super.onCaptureCompleted(session, request, result);
Toast.makeText(AndroidCameraApi.this, "Saved:" + file, Toast.LENGTH_SHORT).show();
createCameraPreview();
}
};
protected void startBackgroundThread() {
mBackgroundThread = new HandlerThread("Camera Background");
mBackgroundThread.start();
mBackgroundHandler = new Handler(mBackgroundThread.getLooper());
}
protected void stopBackgroundThread() {
mBackgroundThread.quitSafely();
try {
mBackgroundThread.join();
mBackgroundThread = null;
mBackgroundHandler = null;
} catch (InterruptedException e) {
e.printStackTrace();
}
}
protected void takePicture() {
if(null == cameraDevice) {
Log.e(TAG, "cameraDevice is null");
return;
}
CameraManager manager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
try {
CameraCharacteristics characteristics = manager.getCameraCharacteristics(cameraDevice.getId());
Size[] jpegSizes = null;
if (characteristics != null) {
jpegSizes = characteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP).getOutputSizes(ImageFormat.JPEG);
}
int width = 640;
int height = 480;
if (jpegSizes != null && 0 < jpegSizes.length) {
width = jpegSizes[0].getWidth();
height = jpegSizes[0].getHeight();
}
ImageReader reader = ImageReader.newInstance(width, height, ImageFormat.JPEG, 1);
List<Surface> outputSurfaces = new ArrayList<Surface>(2);
outputSurfaces.add(reader.getSurface());
outputSurfaces.add(new Surface(textureView.getSurfaceTexture()));
final CaptureRequest.Builder captureBuilder = cameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_STILL_CAPTURE);
captureBuilder.addTarget(reader.getSurface());
captureBuilder.set(CaptureRequest.CONTROL_MODE, CameraMetadata.CONTROL_MODE_AUTO);
// Orientation
int rotation = getWindowManager().getDefaultDisplay().getRotation();
captureBuilder.set(CaptureRequest.JPEG_ORIENTATION, ORIENTATIONS.get(rotation));
final File file = new File(Environment.getExternalStorageDirectory()+"/pic.jpg");
ImageReader.OnImageAvailableListener readerListener = new ImageReader.OnImageAvailableListener() {
@Override
public void onImageAvailable(ImageReader reader) {
Image image = null;
try {
image = reader.acquireLatestImage();
ByteBuffer buffer = image.getPlanes()[0].getBuffer();
byte[] bytes = new byte[buffer.capacity()];
buffer.get(bytes);
save(bytes);
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (image != null) {
image.close();
}
}
}
private void save(byte[] bytes) throws IOException {
OutputStream output = null;
try {
output = new FileOutputStream(file);
output.write(bytes);
} finally {
if (null != output) {
output.close();
}
}
}
};
reader.setOnImageAvailableListener(readerListener, mBackgroundHandler);
final CameraCaptureSession.CaptureCallback captureListener = new CameraCaptureSession.CaptureCallback() {
@Override
public void onCaptureCompleted(CameraCaptureSession session, CaptureRequest request, TotalCaptureResult result) {
super.onCaptureCompleted(session, request, result);
Toast.makeText(AndroidCameraApi.this, "Saved:" + file, Toast.LENGTH_SHORT).show();
createCameraPreview();
}
};
cameraDevice.createCaptureSession(outputSurfaces, new CameraCaptureSession.StateCallback() {
@Override
public void onConfigured(CameraCaptureSession session) {
try {
session.capture(captureBuilder.build(), captureListener, mBackgroundHandler);
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
@Override
public void onConfigureFailed(CameraCaptureSession session) {
}
}, mBackgroundHandler);
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
protected void createCameraPreview() {
try {
SurfaceTexture texture = textureView.getSurfaceTexture();
assert texture != null;
texture.setDefaultBufferSize(imageDimension.getWidth(), imageDimension.getHeight());
Surface surface = new Surface(texture);
captureRequestBuilder = cameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
captureRequestBuilder.addTarget(surface);
cameraDevice.createCaptureSession(Arrays.asList(surface), new CameraCaptureSession.StateCallback(){
@Override
public void onConfigured(@NonNull CameraCaptureSession cameraCaptureSession) {
//The camera is already closed
if (null == cameraDevice) {
return;
}
// When the session is ready, we start displaying the preview.
cameraCaptureSessions = cameraCaptureSession;
updatePreview();
}
@Override
public void onConfigureFailed(@NonNull CameraCaptureSession cameraCaptureSession) {
Toast.makeText(AndroidCameraApi.this, "Configuration change", Toast.LENGTH_SHORT).show();
}
}, null);
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
private void openCamera() {
CameraManager manager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
Log.e(TAG, "is camera open");
try {
cameraId = manager.getCameraIdList()[0];
CameraCharacteristics characteristics = manager.getCameraCharacteristics(cameraId);
StreamConfigurationMap map = characteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);
assert map != null;
imageDimension = map.getOutputSizes(SurfaceTexture.class)[0];
// Add permission for camera and let user grant the permission
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(AndroidCameraApi.this, new String[]{Manifest.permission.CAMERA, Manifest.permission.WRITE_EXTERNAL_STORAGE}, REQUEST_CAMERA_PERMISSION);
return;
}
manager.openCamera(cameraId, stateCallback, null);
} catch (CameraAccessException e) {
e.printStackTrace();
}
Log.e(TAG, "openCamera X");
}
protected void updatePreview() {
if(null == cameraDevice) {
Log.e(TAG, "updatePreview error, return");
}
captureRequestBuilder.set(CaptureRequest.CONTROL_MODE, CameraMetadata.CONTROL_MODE_AUTO);
try {
cameraCaptureSessions.setRepeatingRequest(captureRequestBuilder.build(), null, mBackgroundHandler);
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
private void closeCamera() {
if (null != cameraDevice) {
cameraDevice.close();
cameraDevice = null;
}
if (null != imageReader) {
imageReader.close();
imageReader = null;
}
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
if (requestCode == REQUEST_CAMERA_PERMISSION) {
if (grantResults[0] == PackageManager.PERMISSION_DENIED) {
// close the app
Toast.makeText(AndroidCameraApi.this, "Sorry!!!, you can't use this app without granting permission", Toast.LENGTH_LONG).show();
finish();
}
}
}
@Override
protected void onResume() {
super.onResume();
Log.e(TAG, "onResume");
startBackgroundThread();
if (textureView.isAvailable()) {
openCamera();
} else {
textureView.setSurfaceTextureListener(textureListener);
}
}
@Override
protected void onPause() {
Log.e(TAG, "onPause");
//closeCamera();
stopBackgroundThread();
super.onPause();
}
}
try this code it helps you.
来源：https://stackoverflow.com/questions/49547673/why-camera2-api-working-not-correct