如何在自定义相机中捕获图像，然后将该图像保存在 android 中？
问问题
107155 次
4 回答
105
请看下面的答案。
Custom_CameraActivity.java
public class Custom_CameraActivity extends Activity {
private Camera mCamera;
private CameraPreview mCameraPreview;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mCamera = getCameraInstance();
mCameraPreview = new CameraPreview(this, mCamera);
FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);
preview.addView(mCameraPreview);
Button captureButton = (Button) findViewById(R.id.button_capture);
captureButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
mCamera.takePicture(null, null, mPicture);
}
});
}
/**
* Helper method to access the camera returns null if it cannot get the
* camera or does not exist
*
* @return
*/
private Camera getCameraInstance() {
Camera camera = null;
try {
camera = Camera.open();
} catch (Exception e) {
// cannot get camera or does not exist
}
return camera;
}
PictureCallback mPicture = new PictureCallback() {
@Override
public void onPictureTaken(byte[] data, Camera camera) {
File pictureFile = getOutputMediaFile();
if (pictureFile == null) {
return;
}
try {
FileOutputStream fos = new FileOutputStream(pictureFile);
fos.write(data);
fos.close();
} catch (FileNotFoundException e) {
} catch (IOException e) {
}
}
};
private static File getOutputMediaFile() {
File mediaStorageDir = new File(
Environment
.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES),
"MyCameraApp");
if (!mediaStorageDir.exists()) {
if (!mediaStorageDir.mkdirs()) {
Log.d("MyCameraApp", "failed to create directory");
return null;
}
}
// Create a media file name
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss")
.format(new Date());
File mediaFile;
mediaFile = new File(mediaStorageDir.getPath() + File.separator
+ "IMG_" + timeStamp + ".jpg");
return mediaFile;
}
}
CameraPreview.java
public class CameraPreview extends SurfaceView implements
SurfaceHolder.Callback {
private SurfaceHolder mSurfaceHolder;
private Camera mCamera;
// Constructor that obtains context and camera
@SuppressWarnings("deprecation")
public CameraPreview(Context context, Camera camera) {
super(context);
this.mCamera = camera;
this.mSurfaceHolder = this.getHolder();
this.mSurfaceHolder.addCallback(this);
this.mSurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
@Override
public void surfaceCreated(SurfaceHolder surfaceHolder) {
try {
mCamera.setPreviewDisplay(surfaceHolder);
mCamera.startPreview();
} catch (IOException e) {
// left blank for now
}
}
@Override
public void surfaceDestroyed(SurfaceHolder surfaceHolder) {
mCamera.stopPreview();
mCamera.release();
}
@Override
public void surfaceChanged(SurfaceHolder surfaceHolder, int format,
int width, int height) {
// start preview with new settings
try {
mCamera.setPreviewDisplay(surfaceHolder);
mCamera.startPreview();
} catch (Exception e) {
// intentionally left blank for a test
}
}
}
主要的.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="horizontal" >
<FrameLayout
android:id="@+id/camera_preview"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1" />
<Button
android:id="@+id/button_capture"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:text="Capture" />
</LinearLayout>
将以下行添加到您的 androidmanifest.xml 文件中
<uses-feature android:name="android.hardware.camera" />
<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
于 2012-06-06T11:58:23.837 回答
7
关注片段将帮助您
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="de.vogella.cameara.api"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk android:minSdkVersion="15" />
<uses-permission android:name="android.permission.CAMERA"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<application
android:icon="@drawable/ic_launcher"
android:label="@string/app_name" >
<activity
android:name="de.vogella.camera.api.MakePhotoActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
主要的.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<Button
android:id="@+id/captureFront"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:onClick="onClick"
android:text="Make Photo" />
</RelativeLayout>
PhotoHandler.java
package org.sample;
import java.io.File;
import java.io.FileOutputStream;
import java.text.SimpleDateFormat;
import java.util.Date;
import android.content.Context;
import android.hardware.Camera;
import android.hardware.Camera.PictureCallback;
import android.os.Environment;
import android.util.Log;
import android.widget.Toast;
public class PhotoHandler implements PictureCallback {
private final Context context;
public PhotoHandler(Context context) {
this.context = context;
}
@Override
public void onPictureTaken(byte[] data, Camera camera) {
File pictureFileDir = getDir();
if (!pictureFileDir.exists() && !pictureFileDir.mkdirs()) {
Log.d(Constants.DEBUG_TAG, "Can't create directory to save image.");
Toast.makeText(context, "Can't create directory to save image.",
Toast.LENGTH_LONG).show();
return;
}
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyymmddhhmmss");
String date = dateFormat.format(new Date());
String photoFile = "Picture_" + date + ".jpg";
String filename = pictureFileDir.getPath() + File.separator + photoFile;
File pictureFile = new File(filename);
try {
FileOutputStream fos = new FileOutputStream(pictureFile);
fos.write(data);
fos.close();
Toast.makeText(context, "New Image saved:" + photoFile,
Toast.LENGTH_LONG).show();
} catch (Exception error) {
Log.d(Constants.DEBUG_TAG, "File" + filename + "not saved: "
+ error.getMessage());
Toast.makeText(context, "Image could not be saved.",
Toast.LENGTH_LONG).show();
}
}
private File getDir() {
File sdDir = Environment
.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
return new File(sdDir, "CameraAPIDemo");
}
}
MakePhotoActivity.java
package org.sample;
import android.app.Activity;
import android.content.pm.PackageManager;
import android.hardware.Camera;
import android.hardware.Camera.CameraInfo;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Toast;
import de.vogella.cameara.api.R;
public class MakePhotoActivity extends Activity {
private final static String DEBUG_TAG = "MakePhotoActivity";
private Camera camera;
private int cameraId = 0;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// do we have a camera?
if (!getPackageManager()
.hasSystemFeature(PackageManager.FEATURE_CAMERA)) {
Toast.makeText(this, "No camera on this device", Toast.LENGTH_LONG)
.show();
} else {
cameraId = findFrontFacingCamera();
camera = Camera.open(cameraId);
if (cameraId < 0) {
Toast.makeText(this, "No front facing camera found.",
Toast.LENGTH_LONG).show();
}
}
}
public void onClick(View view) {
camera.takePicture(null, null,
new PhotoHandler(getApplicationContext()));
}
private int findFrontFacingCamera() {
int cameraId = -1;
// Search for the front facing camera
int numberOfCameras = Camera.getNumberOfCameras();
for (int i = 0; i < numberOfCameras; i++) {
CameraInfo info = new CameraInfo();
Camera.getCameraInfo(i, info);
if (info.facing == CameraInfo.CAMERA_FACING_FRONT) {
Log.d(DEBUG_TAG, "Camera found");
cameraId = i;
break;
}
}
return cameraId;
}
@Override
protected void onPause() {
if (camera != null) {
camera.release();
camera = null;
}
super.onPause();
}
}
于 2012-06-06T12:01:52.290 回答
4
于 2013-12-21T14:43:18.807 回答
-3
showbookimage.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// create intent with ACTION_IMAGE_CAPTURE action
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
/**
Here REQUEST_IMAGE is the unique integer value you can pass it any integer
**/
// start camera activity
startActivityForResult(intent, TAKE_PICTURE);
}
}
);
然后你现在可以给图像一个文件名，如下所示，然后将其转换为位图，然后再转换为文件
private void createImageFile(Bitmap bitmap) throws IOException {
// Create an image file name
ByteArrayOutputStream bytes = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.JPEG, 40, bytes);
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
String imageFileName = "JPEG_" + timeStamp + "_";
File storageDir = Environment.getExternalStoragePublicDirectory(
Environment.DIRECTORY_PICTURES);
File image = File.createTempFile(
imageFileName, /* prefix */
".jpg", /* suffix */
storageDir /* directory */
);
FileOutputStream stream = new FileOutputStream(image);
stream.write(bytes.toByteArray());
stream.close();
// Save a file: path for use with ACTION_VIEW intents
mCurrentPhotoPath = "file:" + image.getAbsolutePath();
fileUri = image.getAbsolutePath();
Picasso.with(getActivity()).load(image).into(showbookimage);
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent intent) {
if (requestCode == TAKE_PICTURE && resultCode== Activity.RESULT_OK && intent != null){
// get bundle
Bundle extras = intent.getExtras();
// get
bitMap = (Bitmap) extras.get("data");
// showbookimage.setImageBitmap(bitMap);
try {
createImageFile(bitMap);
} catch (IOException e) {
e.printStackTrace();
}
}
}
使用毕加索图像显示相当快
于 2015-10-02T13:32:28.953 回答