android - 将从相机拍摄的图像保存到内部存储器

Question

我刚开始学习 Android 编程，我正在创建一个 android 应用程序，允许用户在其中键入信息，使用 ImageView 拍照并保存信息。我已经到了能够显示 ImageView 中拍摄的图像的地步。但是，我无法将拍摄的图像保存到手机的内部存储器中。这意味着，每当我尝试保存信息时，包括 ImageView(来自相机的图像)，只有图像消失了。我在 http://www.androidhive.info/2013/09/android-working-with-camera-api/ 上遵循了本指南但它不起作用，因为我的手机没有 SD 卡存储空间。

我在这里阅读了很多问题，但它们并没有解决问题。

因此，如果有人能给我一个详细的过程，说明如何以这样一种方式编辑此代码，以便我可以将图像保存到我的内部存储中或从中读取图像，那就太好了!谢谢。

/**
 * returning image / video
 */
private static File getOutputMediaFile(int type) {

    // External sdcard location
    File mediaStorageDir = new File(
            Environment
                    .getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES),
            IMAGE_DIRECTORY_NAME);

    // Create the storage directory if it does not exist
    if (!mediaStorageDir.exists()) {
        if (!mediaStorageDir.mkdirs()) {
            Log.d(IMAGE_DIRECTORY_NAME, "Oops! Failed create "
                    + IMAGE_DIRECTORY_NAME + " directory");
            return null;
        }
    }
}

这是我当前的代码:

private static final String IMAGE_DIRECTORY_NAME = "Hello Camera";
private Uri fileUri; // file url to store image/video
private ImageView ItemPic;
private static final int CAMERA_CAPTURE_IMAGE_REQUEST_CODE = 100;
public static final int MEDIA_TYPE_IMAGE = 1;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.new_entry);

    date = (EditText) findViewById(R.id.date);
    amount = (EditText) findViewById(R.id.amount);
    item = (EditText) findViewById(R.id.item);

    add = (Button) findViewById(R.id.add_b);
    add.setOnClickListener(onAdd);

    camera = (ImageButton) findViewById(R.id.camera);
    camera.setOnClickListener(new View.OnClickListener() {
       @Override
       public void onClick(View v) {
           // capture picture
           captureImage();
          //  Intent cameraIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
           // startActivityForResult(cameraIntent, CAMERA_REQUEST);
       }
   });

    ItemPic = (ImageView) findViewById(R.id.itempic);

    entryId = getIntent().getStringExtra("ID");
    if (entryId != null) {
        load();
    }
}

    /*
 * Capturing Camera Image will lauch camera app requrest image capture
*/
private void captureImage() {
    Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);

    fileUri = getOutputMediaFileUri(MEDIA_TYPE_IMAGE);

    intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri);

    // start the image capture Intent
    startActivityForResult(intent, CAMERA_CAPTURE_IMAGE_REQUEST_CODE);
}

/**
 * Here we store the file url as it will be null after returning from camera
 * app
 */
@Override
protected void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);

    // save file url in bundle as it will be null on scren orientation
    // changes
    outState.putParcelable("file_uri", fileUri);
}

@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
    super.onRestoreInstanceState(savedInstanceState);

    // get the file url
    fileUri = savedInstanceState.getParcelable("file_uri");
}

/**
 * Receiving activity result method will be called after closing the camera
 * */
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    // if the result is capturing Image
    if (requestCode == CAMERA_CAPTURE_IMAGE_REQUEST_CODE) {
        if (resultCode == RESULT_OK) {
            // successfully captured the image
            // display it in image view
            previewCapturedImage();
        } else if (resultCode == RESULT_CANCELED) {
            // user cancelled Image capture
            Toast.makeText(getApplicationContext(),
                    "User cancelled image capture", Toast.LENGTH_SHORT)
                    .show();
        } else {
            // failed to capture image
            Toast.makeText(getApplicationContext(),
                    "Sorry! Failed to capture image", Toast.LENGTH_SHORT)
                    .show();
        }
    }
}

/**
 * Display image from a path to ImageView
 */
private void previewCapturedImage() {
    try {
        ItemPic.setVisibility(View.VISIBLE);

        // bimatp factory
        BitmapFactory.Options options = new BitmapFactory.Options();

        // downsizing image as it throws OutOfMemory Exception for larger
        // images
        options.inSampleSize = 8;

        final Bitmap bitmap = BitmapFactory.decodeFile(fileUri.getPath(),
                options);

        ItemPic.setImageBitmap(bitmap);

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

/**
 * ------------ Helper Methods ----------------------
 * */

/**
 * Creating file uri to store image/video
 */
public Uri getOutputMediaFileUri(int type) {
    return Uri.fromFile(getOutputMediaFile(type));
}


/**
 * returning image / video
 */
private static File getOutputMediaFile(int type) {

    // External sdcard location
    File mediaStorageDir = new File(
            Environment
                    .getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES),
            IMAGE_DIRECTORY_NAME);

    // Create the storage directory if it does not exist
    if (!mediaStorageDir.exists()) {
        if (!mediaStorageDir.mkdirs()) {
            Log.d(IMAGE_DIRECTORY_NAME, "Oops! Failed create "
                    + IMAGE_DIRECTORY_NAME + " directory");
            return null;
        }
    }

    // Create a media file name
    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss",
            Locale.getDefault()).format(new Date());
    File mediaFile;
    if (type == MEDIA_TYPE_IMAGE) {
        mediaFile = new File(mediaStorageDir.getPath() + File.separator
                + "IMG_" + timeStamp + ".jpg");
    } else {
        return null;
    }

    return mediaFile;
}

Answer 1

getOutputMediaFile() 返回目录，而不是文件。您需要指定要写入图像的(尚不存在的)文件的路径。

这在 this sample application 的 Activity 中得到了说明。 :

package com.commonsware.android.camcon;

import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import java.io.File;

public class CameraContentDemoActivity extends Activity {
  private static final int CONTENT_REQUEST=1337;
  private File output=null;

  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    Intent i=new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    File dir=
        Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM);

    output=new File(dir, "CameraContentDemo.jpeg");
    i.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(output));

    startActivityForResult(i, CONTENT_REQUEST);
  }

  @Override
  protected void onActivityResult(int requestCode, int resultCode,
                                  Intent data) {
    if (requestCode == CONTENT_REQUEST) {
      if (resultCode == RESULT_OK) {
        Intent i=new Intent(Intent.ACTION_VIEW);

        i.setDataAndType(Uri.fromFile(output), "image/jpeg");
        startActivity(i);
        finish();
      }
    }
  }
}