使用相机时应用程序崩溃

Question

我是 Android 新手，这几天一直在为此苦苦挣扎，我有我的应用程序和一个打开相机的按钮，当我使用相机拍照并将其存储在设备上的文件夹中时，我有一个按钮可以将此图片发送到数据库但应用程序崩溃，我已经实现了从图库中选择图片没有问题的相同操作。我已经阅读了可能导致此问题的原因，并且已经发布了有关此问题的信息，但是仍然无法弄清楚出了什么问题。我想我可能对为什么会发生这种情况有一些想法，但不知道如何解决。

所以我不知道应用程序在该行崩溃的原因是否是因为光标所引用的图片不在该文件夹中，而是在为存储图片或接收文件路径而创建的图片上这是空的。我真的希望有人能帮助我。

这是代码：

 botonflotante.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
            filePath = Uri.fromFile(getOutputMediaFile());
            //filePath = getOutputMediaFile(MEDIA_TYPE_IMAGE);
            intent.putExtra(MediaStore.EXTRA_OUTPUT, filePath);
            startActivityForResult(intent, CAM_REQUEST);
        }
    });

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);

    if(requestCode == CAM_REQUEST && resultCode == Activity.RESULT_OK){
try {
            bitmap = MediaStore.Images.Media.getBitmap(getActivity().getContentResolver(), (filePath));
            imageView.setImageBitmap(bitmap);
  getActivity().sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, filePath));

        } catch (IOException e) {
            e.printStackTrace();
        }


 public String getPath(Uri uri) {
    Cursor cursor = getActivity().getContentResolver().query(uri, null, null, null, null);
        cursor.moveToFirst();
        String document_id = cursor.getString(0);
        document_id = document_id.substring(document_id.lastIndexOf(":") + 1);
        cursor.close();

    cursor = getActivity().getContentResolver().query(
                android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
                null, MediaStore.Images.Media._ID + " = ? ", new String[]{document_id}, null);
        cursor.moveToFirst();
        String path = cursor.getString(cursor.getColumnIndex(MediaStore.Images.Media.DATA));
        cursor.close();
        return path;

 private static File getOutputMediaFile(){
    File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(   //getExternalStoragePublicDirectory
            Environment.DIRECTORY_PICTURES), "Vallarta en tus manos Nougat");

    if (!mediaStorageDir.exists()){
        if (!mediaStorageDir.mkdirs()){
            Log.d("Vallarta en tus manos", "failed to create directory");
            return null;
        }
    }

    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
    return new File(mediaStorageDir.getPath() + File.separator +
            "IMG_"+ timeStamp + ".jpg");
}

   public class CargarDatos extends AsyncTask<String, Void, String> {
    protected String doInBackground(String... urls) {

        ////////////////-------------
        String correo = campo_correo.getText().toString().trim();
        String nombre = campo_nombre.getText().toString().trim();
        String apellido= campo_apellido.getText().toString().trim();
        String telefono= campo_telefono.getText().toString().trim();
        String categoria= customspinner.getSelectedItem().toString().trim();
        String titulo = campo_titulo.getText().toString().trim();
        String descripcion = campo_descripcion.getText().toString().trim();
        String latitud = Double.toString(latitudeeeee);
        String longitud = Double.toString(longitudeeee);

        String s = (campo_publico.isChecked() ? "1" : "0");
        String r = (campo_terminos.isChecked() ? "1" : "0");

        //getting the actual path of the image
        String path = getPath(filePath);

        //Uploading code
        try {
            String uploadId = UUID.randomUUID().toString();

            //Creating a multi part request
            new MultipartUploadRequest(TerminosYC.this.getActivity(), uploadId, Constants.UPLOAD_URL)
                    .addFileToUpload(path, "image") //Adding file
                    .addParameter("name",correo) //Adding text parameter to the request
                    .addParameter("nombre",nombre)
                    .addParameter("apellido",apellido)
                    .addParameter("telefono", telefono)
                    .addParameter("categoria", categoria)
                    .addParameter("titulo", titulo)
                    .addParameter("descripcion", descripcion)
                    .addParameter("publico", s)
                    .addParameter("terminos", r)
                    .addParameter("latitud",latitud)
                    .addParameter("longitud",longitud)
                    .setNotificationConfig(new UploadNotificationConfig())
                    .setMaxRetries(2)
                    .startUpload(); //Starting the upload

        } catch (Exception exc) {
            Toast.makeText(TerminosYC.this.getActivity(), exc.getMessage(), Toast.LENGTH_SHORT).show();
        }

        // params comes from the execute() call: params[0] is the url.
        try {
            return downloadUrl(urls[0]);
        } catch (IOException e) {
            return "Unable to retrieve web page. URL may be invalid.";
        }
    }

清单：

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
<protected-broadcast android:name="android.intent.action.MEDIA_MOUNTED" />
<uses-permission-sdk-23 android:name="android.permission.CAMERA" />

LOGCAT：

08-29 22:46:49.200 11628-11628/com.example.lupitagarcia.yosoyvallarta E/AndroidRuntime: FATAL EXCEPTION: main

                                                                                    java.lang.NullPointerException: Attempt to invoke interface method 'boolean android.database.Cursor.moveToFirst()' on a null object reference
                                                                                        at com.example.lupitagarcia.yosoyvallarta.TerminosYC.getPath(TerminosYC.java:529)
                                                                                        at com.example.lupitagarcia.yosoyvallarta.TerminosYC$1.onClick(TerminosYC.java:362)
                                                                                        at android.view.View.performClick(View.java:5721)
                                                                                        at android.widget.TextView.performClick(TextView.java:10936)
                                                                                        at android.view.View$PerformClick.run(View.java:22620)
                                                                                        at android.os.Handler.handleCallback(Handler.java:739)
                                                                                        at android.os.Handler.dispatchMessage(Handler.java:95)
                                                                                        at android.os.Looper.loop(Looper.java:148)
                                                                                        at android.app.ActivityThread.main(ActivityThread.java:7406)
                                                                                        at java.lang.reflect.Method.invoke(Native Method)
                                                                                        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
                                                                                        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)

Answer 1

移动的第一步是为运行时权限添加代码，以启用对外部存储和相机的访问，并添加您对硬件（相机）的访问权限。然后，您可以继续使用相机意图代码。

硬件访问代码

<uses-feature android:name="android.hardware.camera"
                  android:required="true" />

代码 ti 启动相机意图

Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    if (takePictureIntent.resolveActivity(getPackageManager()) != null) {
        startActivityForResult(takePictureIntent, REQUEST_IMAGE_CAPTURE);
    }

在 ActivityResult 上接收图像

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == REQUEST_IMAGE_CAPTURE && resultCode == RESULT_OK) {
        Bundle extras = data.getExtras();
        Bitmap imageBitmap = (Bitmap) extras.get("data");
        mImageView.setImageBitmap(imageBitmap);
    }
}

如果您要保存和管理外部存储中的文件，请不要忘记将文件提供程序添加到您的清单中：

<provider
        android:name="android.support.v4.content.FileProvider"
        android:authorities="com.example.android.fileprovider"
        android:exported="false"
        android:grantUriPermissions="true">
        <meta-data
            android:name="android.support.FILE_PROVIDER_PATHS"
            android:resource="@xml/file_paths"></meta-data>
    </provider>

这将是您的文件路径 XML 文件

<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
    <external-path name="my_images" path="Android/data/com.example.package.name/files/Pictures" />
</paths>

将图像保存在图库中 私人无效画廊AddPic（）{

    Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
    File f = new File(mCurrentPhotoPath);
    Uri contentUri = Uri.fromFile(f);
    mediaScanIntent.setData(contentUri);
    this.sendBroadcast(mediaScanIntent);
}