这是我在Stackoverflow的第一篇文章，我的手指交叉，你可以帮助我。
我最近开始学习Android并且已经决定使用一个简单的应用程序来拍照，然后在应用程序中向用户显示照片将是一个很好的起点。
但是，在Android开发者网站（http://developer.android.com/training/camera/photobasics.html）上关注指南之后，我似乎无法显示图像。
我收到错误：
无法解码流：java.io.FileNotFoundException：file：/storage/emulated/0/Pictures/JPEG_20160101_163802_1697759335.jpg：open failed：ENOENT（没有这样的文件或目录）
我可以看到照片已保存在默认的相机文件夹中，而不是我指定的路径（从开发人员教程中复制/粘贴）。
如果有人能帮助我弄清楚如何在指定文件中保存照片，或者从相机应用程序中恢复保存的位置，我将非常感激。
package uk.co.c2digital.futurefoto;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.ImageView;
import android.widget.Toast;
import java.io.File;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
/**
* The following code is based on the following article: http://developer.android.com/training/camera/photobasics.html
*/
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Log.v("MainActivity", "App Started");
}
/**
* This block of code launches the default camera application
*/
static final int REQUEST_TAKE_PHOTO = 1;
public void dispatchTakePictureIntent(View view) {
Log.v("MainActivity", "dispatchTakePictureIntent() function started");
Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
// Ensure that there's a camera activity to handle the intent
if (takePictureIntent.resolveActivity(getPackageManager()) != null) {
// Out success result to log
Log.v("MainActivity", "Camera app found");
// Create the File where the photo should go
File photoFile = null;
try {
photoFile = createImageFile();
Log.v("MainActivity","Image will be saved to: " + photoFile);
} catch (IOException ex) {
// Error occurred while creating the File
Toast.makeText(this, "Unable to save image", Toast.LENGTH_SHORT).show();
Log.v("MainActivity", "Error while attempting to run createImageFile()");
}
// Continue only if the File was successfully created
if (photoFile != null) {
Log.v("MainActivity","File created");
takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT,
Uri.fromFile(photoFile));
startActivityForResult(takePictureIntent, REQUEST_TAKE_PHOTO);
}
} else {
Toast.makeText(this, "Unable to launch camera app", Toast.LENGTH_SHORT).show();
Log.v("MainActivity","Unable to find camera app");
}
}
/**
* End of camera launch code
*/
/**
* This block of code creates a unique file name for captured photos to prevent naming collisions
*/
String mCurrentPhotoPath;
public File createImageFile() throws IOException {
Log.v("MainActivity","createImageFile() functions started");
// 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;
}
/**
* End of unique file name code
*/
/**
* This block of code decodes and scales the photo and displays in photoView
*/
public void setPic() {
Log.v("MainActivity","setPic() function started");
ImageView mImageView = (ImageView) findViewById(R.id.imageViewer);
// Get the dimensions of the View
int targetW = mImageView.getWidth();
int targetH = mImageView.getHeight();
// Get the dimensions of the bitmap
BitmapFactory.Options bmOptions = new BitmapFactory.Options();
bmOptions.inJustDecodeBounds = true;
BitmapFactory.decodeFile(mCurrentPhotoPath, 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;
Bitmap bitmap = BitmapFactory.decodeFile(mCurrentPhotoPath, bmOptions);
mImageView.setImageBitmap(bitmap);
}
/**
* End of photo scaling code
*/
/**
* THis block of code allows the created photo to be made available to the photo gallery
*/
private void galleryAddPic() {
Log.v("MainActivity", "galleryAddPic() function started");
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);
}
/**
* End of gallery code
*/
/**
* This block of code handles the responce from the cameras intent
*/
public void onActivityResult(int RequestCode, int ResultCode, Intent data) {
Log.v("MainActivity","onActivityResult() function started");
if (RequestCode == REQUEST_TAKE_PHOTO) {
Log.v("MainActivity","RequestCode matched REQUEST_TAKE_PHOTO");
if (ResultCode == RESULT_OK) {
Log.v("MainActivity","ResultCode was OK");
// galleryAddPic();
setPic();
} else {
Log.v("MainActivity","ResultCode was not OK");
Log.v("MainActivity","ResultCode was: " + ResultCode);
}
} else {
Log.v("MainActivity","RequestCode did not equal REQUEST_TAKE_PHOTO");
Log.v("MainActivity","Request Code was: " + RequestCode);
}
}
}
答案 0 :(得分：2)
这是我使用的方法：
Uri newPhotoUri;
public void takePhoto() {
// create Intent to take a picture and return control to the calling application
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
newPhotoUri = Uri.fromFile(new File(filename)); // create a file to save the image
intent.putExtra(MediaStore.EXTRA_OUTPUT, newPhotoUri); // set the image file name
// start the image capture Intent
startActivityForResult(intent, CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE);
}
然后：
/**
* Called when returning from the camera request.
*/
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE) {
Log.d(TAG, "Received camera activity result");
if (resultCode == RESULT_OK) {
String resultPath = "";
if (data == null) {
if (this.newPhotoUri != null) {
Log.d(TAG, "Intent data is null, trying with uri " + this.newPhotoUri.getPath());
resultPath = this.newPhotoUri.getPath();
} else {
Log.d(TAG, "Intent data and photo Uri are null, exiting");
return;
}
} else {
// Image captured and saved to fileUri specified in the Intent
Log.d(TAG, "Image saved to: " + data.getData());
resultPath = data.getData().toString();
}
// process resultPath
} else if (resultCode == RESULT_CANCELED) {
// User cancelled the image capture
Log.d(TAG, "User cancelled");
} else {
// Image capture failed
}
}
}
对于某些设备，不保证使用媒体商店的位置，因此这是一种实用的方法。