摄像头活动返回空android
我正在构建一个应用程序，在该应用程序中，我希望通过默认相机活动捕获图像，然后返回到我的活动，并将该图像加载到ImageView中。问题是摄影机活动始终返回null。在我的摄像头活动返回空android,android,android-camera,Android,Android Camera,我正在构建一个应用程序，在该应用程序中，我希望通过默认相机活动捕获图像，然后返回到我的活动，并将该图像加载到ImageView中。问题是摄影机活动始终返回null。在我的onActivityResult（int-requestCode，int-resultCode，Intent-data）方法中，我获取的数据为null。这是我的密码： public class CameraCapture extends Activity { protected boolean _taken = tru
onActivityResult（int-requestCode，int-resultCode，Intent-data）nullpublic class CameraCapture extends Activity {
protected boolean _taken = true;
File sdImageMainDirectory;
Uri outputFileUri;
protected static final String PHOTO_TAKEN = "photo_taken";
private static final int CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE = 0;
@Override
public void onCreate(Bundle savedInstanceState) {
try {
super.onCreate(savedInstanceState);
setContentView(R.layout.cameracapturedimage);
File root = new File(Environment
.getExternalStorageDirectory()
+ File.separator + "myDir" + File.separator);
root.mkdirs();
sdImageMainDirectory = new File(root, "myPicName");
startCameraActivity();
} catch (Exception e) {
finish();
Toast.makeText(this, "Error occured. Please try again later.",
Toast.LENGTH_SHORT).show();
}
}
protected void startCameraActivity() {
outputFileUri = Uri.fromFile(sdImageMainDirectory);
Intent intent = new Intent("android.media.action.IMAGE_CAPTURE");
intent.putExtra(MediaStore.EXTRA_OUTPUT, outputFileUri);
startActivityForResult(intent, CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
switch (requestCode) {
case CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE:
{
if(resultCode==Activity.RESULT_OK)
{
try{
ImageView imageView=(ImageView)findViewById(R.id.cameraImage);
imageView.setImageBitmap((Bitmap) data.getExtras().get("data"));
}
catch (Exception e) {
// TODO: handle exception
}
}
break;
}
default:
break;
}
}
@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
if (savedInstanceState.getBoolean(CameraCapture.PHOTO_TAKEN)) {
_taken = true;
}
}
@Override
protected void onSaveInstanceState(Bundle outState) {
outState.putBoolean(CameraCapture.PHOTO_TAKEN, _taken);
}
}
我做错什么了吗？我也有类似的问题。我注释掉了清单文件中的一些行，这导致缩略图数据返回为null 要使其正常工作，您需要以下各项：
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.CAMERA" />
<uses-feature android:name="android.hardware.camera" />
<uses-feature android:name="android.hardware.camera.autofocus" />
还有一种可能会提供额外的信息因为你做得不对，所以你错了 如果将额外参数
MediaStore.extra_OUTPUTonActivityResult有关更多信息，您可以按照下面的说明进行操作，我正在以另一种方式进行操作。data.getData（）字段不保证返回Uri，因此我正在检查它是否为null，如果为null，则图像在附加中。因此，守则是—
if(data.getData()==null){
bitmap = (Bitmap)data.getExtras().get("data");
}else{
bitmap = MediaStore.Images.Media.getBitmap(this.getContentResolver(), data.getData());
}
您可以从发送到camera intent的文件生成位图。请使用此代码
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data){
switch (requestCode) {
case CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE:
{
if(resultCode==Activity.RESULT_OK)
{
int orientation = getOrientationFromExif(sdImageMainDirectory);// get orientation that image taken
BitmapFactory.Options options = new BitmapFactory.Options();
InputStream is = null;
Matrix m = new Matrix();
m.postRotate(orientation);//rotate image
is = new FileInputStream(sdImageMainDirectory);
options.inSampleSize = 4 //(original_image_size/4);
Bitmap bitmap = BitmapFactory.decodeStream(is,null,options);
bitmap = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(),
bitmap.getHeight(), m, true);
// set bitmap to image view
//bitmap.recycle();
}
break;
}
default:
break;
}
}
private int getOrientationFromExif(String imagePath) {
int orientation = -1;
try {
ExifInterface exif = new ExifInterface(imagePath);
int exifOrientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION,
ExifInterface.ORIENTATION_NORMAL);
switch (exifOrientation) {
case ExifInterface.ORIENTATION_ROTATE_270:
orientation = 270;
break;
case ExifInterface.ORIENTATION_ROTATE_180:
orientation = 180;
break;
case ExifInterface.ORIENTATION_ROTATE_90:
orientation = 90;
break;
case ExifInterface.ORIENTATION_NORMAL:
orientation = 0;
break;
default:
break;
}
} catch (IOException e) {
//Log.e(LOG_TAG, "Unable to get image exif orientation", e);
}
return orientation;
}
private static final int TAKE_PHOTO_REQUEST = 1;
private ImageView mImageView;
String mCurrentPhotoPath;
private File photoFile;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_saisir_frais);
mImageView = (ImageView) findViewById(R.id.imageViewPhoto);
dispatchTakePictureIntent();
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == TAKE_PHOTO_REQUEST && resultCode == RESULT_OK) {
// set the dimensions of the image
int targetW =100;
int targetH = 100;
// Get the dimensions of the bitmap
BitmapFactory.Options bmOptions = new BitmapFactory.Options();
bmOptions.inJustDecodeBounds = true;
BitmapFactory.decodeFile(photoFile.getAbsolutePath(), bmOptions);
int photoW = bmOptions.outWidth;
int photoH = bmOptions.outHeight;
// Determine how much to scale down the image
int scaleFactor = Math.min(photoW/targetW, photoH/targetH);
// Decode the image file into a Bitmap sized to fill the View
bmOptions.inJustDecodeBounds = false;
bmOptions.inSampleSize = scaleFactor;
bmOptions.inPurgeable = true;
// stream = getContentResolver().openInputStream(data.getData());
Bitmap bitmap = BitmapFactory.decodeFile(photoFile.getAbsolutePath(),bmOptions);
mImageView.setImageBitmap(bitmap);
}
}
private File createImageFile() throws IOException {
// Create an image file name
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 */
);
// Save a file: path for use with ACTION_VIEW intents
mCurrentPhotoPath = "file:" + image.getAbsolutePath();
return image;
}
private void dispatchTakePictureIntent() {
Intent takePhotoIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
try {
photoFile = createImageFile();
takePhotoIntent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(photoFile));
startActivityForResult(takePhotoIntent, TAKE_PHOTO_REQUEST);
} catch (IOException e) {
e.printStackTrace();
}
}
试试这个教程。它对我有效，并且像往常一样在宣言中使用许可&也是 检查权限
经过大量的积极研究，我终于得出了一个结论。 为此，应将捕获的图像保存到外部存储器中。 然后，在上载时检索。 这样，图像分辨率不会降低，也不会出现NullPointerException！ 我使用时间戳来命名文件，因此每次都会得到一个唯一的文件名
private void fileChooser2() {
StrictMode.VmPolicy.Builder builder = new StrictMode.VmPolicy.Builder();
StrictMode.setVmPolicy(builder.build());
Intent intent=new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
File pictureDirectory = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
String pictureName=getPictureName();
fi=pictureName;
File imageFile=new File(pictureDirectory,pictureName);
Uri pictureUri = Uri.fromFile(imageFile);
intent.putExtra(MediaStore.EXTRA_OUTPUT,pictureUri);
startActivityForResult(intent,PICK_IMAGE_REQUEST2);
}
private String getPictureName() {
SimpleDateFormat adf=new SimpleDateFormat("yyyyMMdd_HHmmss");
String timestamp = adf.format(new Date());
return "The New image"+timestamp+".jpg";//give a unique string so that the imagename cant be overlapped with other apps'image formats
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if(requestCode==PICK_IMAGE_REQUEST2 && resultCode==RESULT_OK )//&& data!=null && data.getData()!=null)
{
final ProgressDialog progressDialog = new ProgressDialog(this);
progressDialog.setTitle("Uploading");
progressDialog.show();
Toast.makeText(getApplicationContext(),"2",Toast.LENGTH_SHORT).show();
File picDir=Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
File imageFile=new File(picDir.getAbsoluteFile(),fi);
filePath=Uri.fromFile(imageFile);
try {
}catch (Exception e)
{
e.printStackTrace();
}
StorageReference riversRef = storageReference.child(mAuth.getCurrentUser().getUid()+"/2");
riversRef.putFile(filePath)
.addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {
@Override
public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {
progressDialog.dismiss();
Toast.makeText(getApplicationContext(), "File Uploaded ", Toast.LENGTH_LONG).show();
}
})
.addOnFailureListener(new OnFailureListener() {
@Override
public void onFailure(@NonNull Exception exception) {
progressDialog.dismiss();
Toast.makeText(getApplicationContext(), exception.getMessage(), Toast.LENGTH_LONG).show();
}
})
.addOnProgressListener(new OnProgressListener<UploadTask.TaskSnapshot>() {
@Override
public void onProgress(UploadTask.TaskSnapshot taskSnapshot) {
double progress = (100.0 * taskSnapshot.getBytesTransferred()) / taskSnapshot.getTotalByteCount();
progressDialog.setMessage("Uploaded " + ((int) progress) + "%...");
}
});
@覆盖
受保护的void onActivityResult（int请求代码、int结果代码、意图数据）{
super.onActivityResult（请求代码、结果代码、数据）；
if（requestCode==PICK\u IMAGE\u REQUEST2&&resultCode==RESULT\u OK）/&&data！=null&&data.getData（）！=null）
{
final ProgressDialog ProgressDialog=新建ProgressDialog（此）；
progressDialog.setTitle（“上传”）；
progressDialog.show（）；
Toast.makeText（getApplicationContext（），“2”，Toast.LENGTH_SHORT.show（）；
文件picDir=Environment.getExternalStoragePublicDirectory（Environment.DIRECTORY\u图片）；
File imageFile=新文件（picDir.getAbsoluteFile（），fi）；
filePath=Uri.fromFile（imageFile）；
试一试{
}捕获（例外e）
{
e、 printStackTrace（）；
}
storagereferef=StorageReference.child（mAuth.getCurrentUser（）.getUid（）+“/2”）；
riversRef.putFile（文件路径）
.addOnSuccessListener（新的OnSuccessListener（）{
@凌驾
成功时公共无效（UploadTask.TaskSnapshot TaskSnapshot）{
progressDialog.disclose（）；
Toast.makeText（getApplicationContext（），“上传文件”，Toast.LENGTH_LONG.show（）；
}
})
.addOnFailureListener（新的OnFailureListener（）{
@凌驾
public void onFailure（@NonNull异常）{
progressDialog.disclose（）；
Toast.makeText（getApplicationContext（），exception.getMessage（），Toast.LENGTH_LONG.show（）；
}
})
.addOnProgressListener（新的OnProgressListener（）{
@凌驾
public void onProgress（UploadTask.TaskSnapshot TaskSnapshot）{
双进度=（100.0*taskSnapshot.GetByTestTransferred（））/taskSnapshot.getTotalByteCount（）；
setMessage（“上传的”+（（int）进度）+“%…”；
}
});
编辑：授予摄像头权限以及从清单中的存储中写入和读取的权限。从摄像头读取时，少数手机将返回null。下面的解决方法将解决此问题。请确保检查数据是否为null
private int CAMERA_NEW = 2;
private String imgPath;
private void takePhotoFromCamera() {
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
intent.putExtra(MediaStore.EXTRA_OUTPUT, setImageUri());
startActivityForResult(intent, CAMERA_NEW);
}
// to get the file path
private Uri setImageUri() {
// Store image in dcim
File file = new File(Environment.getExternalStorageDirectory() + "/DCIM/", "image" + new Date().getTime() + ".png");
Uri imgUri = Uri.fromFile(file);
this.imgPath = file.getAbsolutePath();
return imgUri;
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data)
{
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == CAMERA_NEW) {
try {
Log.i("Crash","CAMERA_NEW");
if(data!=null &&(Bitmap) data.getExtras().get("data")!=null){
bitmap = (Bitmap) data.getExtras().get("data");
personImage.setImageBitmap(bitmap);
Utils.saveImage(bitmap, getActivity());
}else{
File f= new File(imgPath);
BitmapFactory.Options options = new BitmapFactory.Options();
options.inPreferredConfig = Bitmap.Config.ARGB_8888;
options.inSampleSize= 4;
bitmap = BitmapFactory.decodeStream(new FileInputStream(f), null, options);
personImage.setImageBitmap(bitmap);
}
} catch (Exception e) {
e.printStackTrace();
Toast.makeText(getActivity(), "Failed!", Toast.LENGTH_SHORT).show();
}
}
SD卡是否已安装？您可以在哪里看到图像“myPicName”？您在清单中有权限吗？我可以在usb调试时在ddms中看到该文件。我也已授予该权限。如果在imageview中加载图像时使用outputFileUri而不是数据，则可以正常工作。这意味着相机正在捕获图像，但为什么我会被捕获在onactivityresult（）的数据参数中设置null方法如果你允许访问你的存储，请注意。我也有同样的问题，我担心这些权限不会改变任何事情。至少对我来说，似乎没有解决办法。我已经搜索了好几天，为什么会是这样？我非常沮丧，因为我不能用应用程序拍摄一张照片。@cubsink是我吗t三星…？很抱歉最近的回复@Merlin。但是是的，它是三星的设备。那是一年多以前的事了，我想现在情况已经改变了。@cubsink，ach it wa
private String getPictureName() {
SimpleDateFormat adf=new SimpleDateFormat("yyyyMMdd_HHmmss");
String timestamp = adf.format(new Date());
return "The New image"+timestamp+".jpg";//give a unique string so that the imagename cant be overlapped with other apps'image formats
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if(requestCode==PICK_IMAGE_REQUEST2 && resultCode==RESULT_OK )//&& data!=null && data.getData()!=null)
{
final ProgressDialog progressDialog = new ProgressDialog(this);
progressDialog.setTitle("Uploading");
progressDialog.show();
Toast.makeText(getApplicationContext(),"2",Toast.LENGTH_SHORT).show();
File picDir=Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
File imageFile=new File(picDir.getAbsoluteFile(),fi);
filePath=Uri.fromFile(imageFile);
try {
}catch (Exception e)
{
e.printStackTrace();
}
StorageReference riversRef = storageReference.child(mAuth.getCurrentUser().getUid()+"/2");
riversRef.putFile(filePath)
.addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {
@Override
public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {
progressDialog.dismiss();
Toast.makeText(getApplicationContext(), "File Uploaded ", Toast.LENGTH_LONG).show();
}
})
.addOnFailureListener(new OnFailureListener() {
@Override
public void onFailure(@NonNull Exception exception) {
progressDialog.dismiss();
Toast.makeText(getApplicationContext(), exception.getMessage(), Toast.LENGTH_LONG).show();
}
})
.addOnProgressListener(new OnProgressListener<UploadTask.TaskSnapshot>() {
@Override
public void onProgress(UploadTask.TaskSnapshot taskSnapshot) {
double progress = (100.0 * taskSnapshot.getBytesTransferred()) / taskSnapshot.getTotalByteCount();
progressDialog.setMessage("Uploaded " + ((int) progress) + "%...");
}
});
private int CAMERA_NEW = 2;
private String imgPath;
private void takePhotoFromCamera() {
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
intent.putExtra(MediaStore.EXTRA_OUTPUT, setImageUri());
startActivityForResult(intent, CAMERA_NEW);
}
// to get the file path
private Uri setImageUri() {
// Store image in dcim
File file = new File(Environment.getExternalStorageDirectory() + "/DCIM/", "image" + new Date().getTime() + ".png");
Uri imgUri = Uri.fromFile(file);
this.imgPath = file.getAbsolutePath();
return imgUri;
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data)
{
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == CAMERA_NEW) {
try {
Log.i("Crash","CAMERA_NEW");
if(data!=null &&(Bitmap) data.getExtras().get("data")!=null){
bitmap = (Bitmap) data.getExtras().get("data");
personImage.setImageBitmap(bitmap);
Utils.saveImage(bitmap, getActivity());
}else{
File f= new File(imgPath);
BitmapFactory.Options options = new BitmapFactory.Options();
options.inPreferredConfig = Bitmap.Config.ARGB_8888;
options.inSampleSize= 4;
bitmap = BitmapFactory.decodeStream(new FileInputStream(f), null, options);
personImage.setImageBitmap(bitmap);
}
} catch (Exception e) {
e.printStackTrace();
Toast.makeText(getActivity(), "Failed!", Toast.LENGTH_SHORT).show();
}
}