试图从Android的图库或相机中获取图像

Question

我正在尝试一个在线教程，用于从图库或照相机将图像加载到imageview中。画廊部分工作正常，但照相机部分强制关闭。从onactvitiyresult检索的数据显示为空。

编码：

package com.example.cameragallerypro;

import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.app.Activity;
import android.content.Intent;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;

public class MainActivity extends Activity {

     Uri selectedImageUri;
      String  selectedPath;
      ImageView preview;
     @Override
     protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      Button b = (Button) findViewById(R.id.bGallery);
      Button bCam= (Button) findViewById(R.id.bCamera);
       preview = (ImageView) findViewById(R.id.preview);
      bCam.setOnClickListener(new OnClickListener() {

       @Override
       public void onClick(View v) {
        // TODO Auto-generated method stub
        Intent cameraIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
                    startActivityForResult(cameraIntent, 100);
       }
      });


      b.setOnClickListener(new OnClickListener() {

       @Override
       public void onClick(View v) {
        // TODO Auto-generated method stub
         openGallery(10);
       }
      });
     }



     public void openGallery(int req_code){

            Intent intent = new Intent();

            intent.setType("image/*");

            intent.setAction(Intent.ACTION_GET_CONTENT);

            startActivityForResult(Intent.createChooser(intent,"Select file to upload "), req_code);

       }

    public void onActivityResult(int requestCode, int resultCode, Intent data) {



            if (resultCode == RESULT_OK) {
             if(data.getData() != null){
               selectedImageUri = data.getData();
             }else{
              Log.d("selectedPath1 : ","Came here its null !");
              Toast.makeText(getApplicationContext(), "failed to get Image!", 500).show();
             }

             if (requestCode == 100 && resultCode == RESULT_OK) { 
                    Bitmap photo = (Bitmap) data.getExtras().get("data");
                    selectedPath = getPath(selectedImageUri);
                    preview.setImageURI(selectedImageUri);
                    Log.d("selectedPath1 : " ,selectedPath);

                }

                if (requestCode == 10)

                {

                   selectedPath = getPath(selectedImageUri);
                   preview.setImageURI(selectedImageUri);
                   Log.d("selectedPath1 : " ,selectedPath);

                }

            }

        }


     public String getPath(Uri uri) {

            String[] projection = { MediaStore.Images.Media.DATA };

            Cursor cursor = managedQuery(uri, projection, null, null, null);

            int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);

            cursor.moveToFirst();

            return cursor.getString(column_index);

        }

    }

日志：

09-17 10:09:30.132: E/AndroidRuntime(7300): FATAL EXCEPTION: main
09-17 10:09:30.132: E/AndroidRuntime(7300): java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=100, result=-1, data=Intent { act=inline-data (has extras) }} to activity {com.example.cameragallerypro/com.example.cameragallerypro.MainActivity}: java.lang.NullPointerException
09-17 10:09:30.132: E/AndroidRuntime(7300):     at android.app.ActivityThread.deliverResults(ActivityThread.java:2536)
09-17 10:09:30.132: E/AndroidRuntime(7300):     at android.app.ActivityThread.handleSendResult(ActivityThread.java:2578)
09-17 10:09:30.132: E/AndroidRuntime(7300):     at android.app.ActivityThread.access$2000(ActivityThread.java:117)
09-17 10:09:30.132: E/AndroidRuntime(7300):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:965)
09-17 10:09:30.132: E/AndroidRuntime(7300):     at android.os.Handler.dispatchMessage(Handler.java:99)
09-17 10:09:30.132: E/AndroidRuntime(7300):     at android.os.Looper.loop(Looper.java:130)
09-17 10:09:30.132: E/AndroidRuntime(7300):     at android.app.ActivityThread.main(ActivityThread.java:3689)
09-17 10:09:30.132: E/AndroidRuntime(7300):     at java.lang.reflect.Method.invokeNative(Native Method)
09-17 10:09:30.132: E/AndroidRuntime(7300):     at java.lang.reflect.Method.invoke(Method.java:507)
09-17 10:09:30.132: E/AndroidRuntime(7300):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:842)
09-17 10:09:30.132: E/AndroidRuntime(7300):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
09-17 10:09:30.132: E/AndroidRuntime(7300):     at dalvik.system.NativeStart.main(Native Method)
09-17 10:09:30.132: E/AndroidRuntime(7300): Caused by: java.lang.NullPointerException
09-17 10:09:30.132: E/AndroidRuntime(7300):     at android.content.ContentResolver.acquireProvider(ContentResolver.java:743)
09-17 10:09:30.132: E/AndroidRuntime(7300):     at android.content.ContentResolver.query(ContentResolver.java:256)
09-17 10:09:30.132: E/AndroidRuntime(7300):     at android.app.Activity.managedQuery(Activity.java:1550)
09-17 10:09:30.132: E/AndroidRuntime(7300):     at com.example.cameragallerypro.MainActivity.getPath(MainActivity.java:104)
09-17 10:09:30.132: E/AndroidRuntime(7300):     at com.example.cameragallerypro.MainActivity.onActivityResult(MainActivity.java:79)
09-17 10:09:30.132: E/AndroidRuntime(7300):     at android.app.Activity.dispatchActivityResult(Activity.java:3908)
09-17 10:09:30.132: E/AndroidRuntime(7300):     at android.app.ActivityThread.deliverResults(ActivityThread.java:2532)
09-17 10:09:30.132: E/AndroidRuntime(7300):     ... 11 more

如何修改代码，使摄像头部件正常工作？

Answer 1

bCam.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub

                from_camera();

            }
        });

        b.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub

                from_gallery();

            }
        });


public void from_camera() {

        Intent cameraIntent = new Intent(
                android.provider.MediaStore.ACTION_IMAGE_CAPTURE);

        startActivityForResult(cameraIntent, 111);

    }


public void from_gallery() {
        Intent intent = new Intent(Intent.ACTION_PICK,
                android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
        startActivityForResult(intent, 222);


    }





    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        // TODO Auto-generated method stub

        if (resultCode == RESULT_OK && requestCode == 111) {
            Bitmap photo = (Bitmap) data.getExtras().get("data");
            preview.setImageBitmap(photo);



        } else if (resultCode == RESULT_OK && requestCode == 222) {

             Uri selectedImage = data.getData();
            String[] filePathColumn = { MediaStore.Images.Media.DATA };

            Cursor cursor = getContentResolver().query(selectedImage,
                    filePathColumn, null, null, null);
            cursor.moveToFirst();

            int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
            String picturePath = cursor.getString(columnIndex);
            cursor.close();


            preview.setImageBitmap(BitmapFactory.decodeFile(picturePath));

        super.onActivityResult(requestCode, resultCode, data);
    }

Answer 2

尝试更换您的生产线：

preview.setImageURI(selectedImageUri);

与此：

preview.setImageBitmap(photo);

Answer 3

请查看以下可能对您有帮助的内容：

public static String TEMP_PHOTO_FILE_NAME;
private File mFileTemp;
int ADD_IMAGE_CAPTURE = 5;

public void takePictureFromCamera() {

        Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);

        try {
            Uri mImageCaptureUri = null;
            String state = Environment.getExternalStorageState();
            TEMP_PHOTO_FILE_NAME = "" + System.currentTimeMillis() + ".jpg";
            if (Environment.MEDIA_MOUNTED.equals(state)) {

                mFileTemp = new File(Environment.getExternalStorageDirectory(),
                        TEMP_PHOTO_FILE_NAME);
            } else {
                mFileTemp = new File(getFilesDir(), TEMP_PHOTO_FILE_NAME);
            }
            if (Environment.MEDIA_MOUNTED.equals(state)) {
                mImageCaptureUri = Uri.fromFile(mFileTemp);
            } else {
                /*
                 * The solution is taken from here:
                 * http://stackoverflow.com/questions
                 * /10042695/how-to-get-camera-result-as-a-uri-in-data-folder
                 */
                mImageCaptureUri = InternalStorageContentProvider.CONTENT_URI;
            }
            intent.putExtra(android.provider.MediaStore.EXTRA_OUTPUT,
                    mImageCaptureUri);
            intent.putExtra("return-data", true);
            startActivityForResult(intent, ADD_IMAGE_CAPTURE);
        } catch (ActivityNotFoundException e) {

        }
    }
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
         if (requestCode == ADD_IMAGE_CAPTURE) {
          try {

                if (mFileTemp.exists()) {
                  String mPartyPicUri = mFileTemp.getPath();
                }
             } catch (Exception e) {
                e.printStackTrace();
            }
        }
      }

Answer 4

尝试这种方式，希望这将帮助您解决问题。

public class MainActivity extends Activity {

    String  selectedPath;
    ImageView preview;
    final private int GALLERY = 1;
    final private int CAPTURE = 2;
    private String imgPath;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button b = (Button) findViewById(R.id.bGallery);
        Button bCam= (Button) findViewById(R.id.bCamera);
        preview = (ImageView) findViewById(R.id.preview);

        bCam.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
                intent.putExtra(MediaStore.EXTRA_OUTPUT, setImageUri());
                startActivityForResult(intent, CAPTURE);
            }
        });


        b.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                Intent intent = new Intent();
                intent.setType("image/*");
                intent.setAction(Intent.ACTION_GET_CONTENT);
                startActivityForResult(Intent.createChooser(intent, ""), GALLERY);
            }
        });
    }


    public 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;
    }

    public String getImagePath() {
        return imgPath;
    }


    public String getAbsolutePath(Uri uri) {
        String[] projection = { MediaStore.MediaColumns.DATA };
        @SuppressWarnings("deprecation")
        Cursor cursor = managedQuery(uri, projection, null, null, null);
        if (cursor != null) {
            int column_index = cursor.getColumnIndexOrThrow(MediaStore.MediaColumns.DATA);
            cursor.moveToFirst();
            return cursor.getString(column_index);
        } else
            return null;
    }

    public Bitmap decodeFile(String path) {
        try {
            // Decode image size
            BitmapFactory.Options o = new BitmapFactory.Options();
            o.inJustDecodeBounds = true;
            BitmapFactory.decodeFile(path, o);
            // The new size we want to scale to
            final int REQUIRED_SIZE = 70;

            // Find the correct scale value. It should be the power of 2.
            int scale = 1;
            while (o.outWidth / scale / 2 >= REQUIRED_SIZE && o.outHeight / scale / 2 >= REQUIRED_SIZE)
                scale *= 2;

            // Decode with inSampleSize
            BitmapFactory.Options o2 = new BitmapFactory.Options();
            o2.inSampleSize = scale;
            return BitmapFactory.decodeFile(path, o2);
        } catch (Throwable e) {
            e.printStackTrace();
        }
        return null;

    }

    public Bitmap decodeFile(Uri path) {
        try {
            // Decode image size
            BitmapFactory.Options o = new BitmapFactory.Options();
            o.inJustDecodeBounds = true;

            BitmapFactory.decodeFile(getAbsolutePath(path), o);

            // The new size we want to scale to
            final int REQUIRED_SIZE = 70;

            // Find the correct scale value. It should be the power of 2.
            int scale = 1;
            while (o.outWidth / scale / 2 >= REQUIRED_SIZE && o.outHeight / scale / 2 >= REQUIRED_SIZE)
                scale *= 2;

            // Decode with inSampleSize
            BitmapFactory.Options o2 = new BitmapFactory.Options();
            o2.inSampleSize = scale;
            return BitmapFactory.decodeFile(getAbsolutePath(path), o2);
        } catch (Throwable e) {
            e.printStackTrace();
        }
        return null;

    }

    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (resultCode == RESULT_OK) {
            if (requestCode == GALLERY) {
                selectedPath = getAbsolutePath(data.getData());
                preview.setImageBitmap(decodeFile(selectedPath));
            } else if (requestCode == CAPTURE) {
                selectedPath = getImagePath();
                preview.setImageBitmap(decodeFile(selectedPath));
            }
        }

    }
}

在AndroidManifest.xml中添加此权限：

<uses-permission android:name="android.permission.CAMERA"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

Answer 5

如下更改摄像机代码。

 if (requestCode == 100 && resultCode == RESULT_OK) { 
        Bundle extras = data.getExtras();
        if (extras != null) {
            Bitmap photo = extras.getParcelable("data");
             preview.setImageBitmap(photo);

}

Answer 6

我真的建议您使用图书馆为您完成艰苦的工作。 您必须看一下这个库 ，从图库或照相机中选择图像要容易得多。 使用上述库，将显示一个对话框，用户可以选择是否要从图库或照相机中获取图像。

只需调用即可显示对话框：

PickImageDialog.on(MainActivity.this, new PickSetup());

使您的活动实现以下目的：

public class YourActivity implements IPickResult.IPickResultBitmap  

然后重写此方法：

@Override
public void onPickImageResult(Bitmap photo) {
     preview.setImageBitmap(photo);
 }