构建应用程序以拍照和上传，但意图数据为空

Question

我正在尝试制作一个拍摄高质量照片并上传它们的应用程序，但最重要的部分之一不起作用，相机。意图数据为空，因此不显示任何图像。我从 https://developer.android.com/training/camera/photobasics#TaskPath 那里接过了信息。 我尝试了不同的方法，但我没有任何效果。

package com.example.gn.nextcamtest;
import android.Manifest;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.net.Uri;
import android.os.Environment;
import android.provider.MediaStore;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v4.content.FileProvider;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
import java.io.File;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
public class MainActivity extends AppCompatActivity {
TextView txt_Test;
Button btn_Cam;
ImageView iv_image;
static final int REQUEST_IMAGE_CAPTURE = 1;
String mCurrentPhotoPath;
public static final int RequestPermissionCode = 1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btn_Cam = (Button) findViewById(R.id.btn_Cam);
iv_image = (ImageView) findViewById(R.id.iv_Test);
txt_Test = (TextView) findViewById(R.id.txt_test);
EnableRuntimePermissionToAccessCamera();
Bundle bundle = getIntent().getExtras();
if (bundle != null) {
txt_Test.setText(" " + bundle.getString("test"));
}
btn_Cam.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
dispatchTakePictureIntent();
}
});
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == REQUEST_IMAGE_CAPTURE && resultCode == RESULT_OK) {
if (data.getExtras() != null && data.getExtras().get("data") instanceof Bitmap) {
Bundle extras = data.getExtras();
Bitmap imageBitmap = (Bitmap) extras.get("data");
iv_image.setImageBitmap(imageBitmap);
// iv_image.setImageBitmap((Bitmap)data.getExtras().get("data"));
} else {
iv_image.setImageResource(R.drawable.ic_launcher_background);
Toast.makeText(this, "Fail to load image", Toast.LENGTH_LONG).show();
}
}
}
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 = getExternalFilesDir(Environment.DIRECTORY_PICTURES);
File image = File.createTempFile(imageFileName, /* prefix */ ".jpg", /* suffix */ storageDir /* directory */ );
// Save a file: path for use with ACTION_VIEW intents
mCurrentPhotoPath = image.getAbsolutePath();
return image;
}
static final int REQUEST_TAKE_PHOTO = 1;
private void dispatchTakePictureIntent() {
Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
// Ensure that there's a camera activity to handle the intent
if (takePictureIntent.resolveActivity(getPackageManager()) != null) {
// Create the File where the photo should go
File photoFile = null;
try {
photoFile = createImageFile();
} catch (IOException ex) {
// Error occurred while creating the File
}
// Continue only if the File was successfully created
if (photoFile != null) {
Uri photoURI = FileProvider.getUriForFile(this, "com.example.gn.nextcamtest.fileprovider", photoFile);
takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI);
startActivityForResult(takePictureIntent, REQUEST_TAKE_PHOTO);
}
}
}
// Requesting runtime permission to access camera.
public void EnableRuntimePermissionToAccessCamera() {
if (ContextCompat.checkSelfPermission(getApplicationContext(), android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(getApplicationContext(), android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(this, new String[] {
android.Manifest.permission.ACCESS_FINE_LOCATION, android.Manifest.permission.ACCESS_COARSE_LOCATION
}, 101);
}
if (ActivityCompat.shouldShowRequestPermissionRationale(this,
Manifest.permission.CAMERA)) {
// Printing toast message after enabling runtime permission.
Toast.makeText(this, "CAMERA permission allows us to Access CAMERA app", Toast.LENGTH_LONG).show();
} else {
ActivityCompat.requestPermissions(this, new String[] {
Manifest.permission.CAMERA
}, RequestPermissionCode);
}
}

@Override
public void onRequestPermissionsResult(int RC, String per[], int[] PResult) {
switch (RC) {
case RequestPermissionCode:
if (PResult.length > 0 && PResult[0] == PackageManager.PERMISSION_GRANTED) {
Toast.makeText(this, "Permission Granted, Now your application can access CAMERA.", Toast.LENGTH_LONG).show();
} else {
Toast.makeText(this, "Permission Canceled, Now your application cannot access CAMERA.", Toast.LENGTH_LONG).show();
}
break;
}
}
}

Answer 1

几天前我也尝试过这个，不得不挣扎很多。然后我自己想通了。

这是我的代码的样子：

1( 在创建中：

capture.setOnClickListener(new View.OnClickListener() {
@RequiresApi(api = Build.VERSION_CODES.M)
@Override
public void onClick(View v) {
if ((checkSelfPermission(Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED)) {
if (checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
requestPermissions(new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, storagePermissionCode);
}
requestPermissions(new String[]{Manifest.permission.CAMERA}, cameraPermissionCode);
} else {
ContentValues values = new ContentValues();
imageUri = getContentResolver().insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);
Intent cameraIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
cameraIntent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);
startActivityForResult(cameraIntent, cameraRequestCode);
}
}
});

2( 在活动结果中：

@RequiresApi(api = Build.VERSION_CODES.M)
@Override
protected void onActivityResult(int requestCode, int resultCode, final Intent data) {
if (requestCode == cameraRequestCode) {
if (resultCode == Activity.RESULT_OK) {
FileOutputStream stream = null;
try {
Bitmap photo = MediaStore.Images.Media.getBitmap(getContentResolver(), imageUri);
String saveFilePath = getRealPathFromURI(imageUri);
stream = new FileOutputStream(saveFilePath);
photo.compress(Bitmap.CompressFormat.JPEG, 25, stream);
} catch (IOException e) {
e.printStackTrace();
Toast.makeText(getApplicationContext(), "Can't save image !", Toast.LENGTH_SHORT).show();
} finally {
try {
if (stream != null) {
stream.close();
Toast.makeText(getApplicationContext(), "Image saved successfully !", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(getApplicationContext(), "Can't save image, try again !", Toast.LENGTH_SHORT).show();
}
} catch (IOException e) {
e.printStackTrace();
}
}
} else if (resultCode == Activity.RESULT_CANCELED) {
Toast.makeText(getApplicationContext(), "Cancelled", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(getApplicationContext(), "Can't capture image !", Toast.LENGTH_SHORT).show();
}
}
}

3( getRealPathFromURI 函数：

public String getRealPathFromURI(Uri contentUri) {
String[] proj = { MediaStore.Images.Media.DATA };
Cursor cursor = managedQuery(contentUri, proj, null, null, null);
int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
cursor.moveToFirst();
return cursor.getString(column_index);
}