Android:从相机获取图片时会发生NPE

Question

我的Android应用有问题.我正MediaStore.ACTION_IMAGE_CAPTURE打算用相机拍照.它适用于大多数设备,但我在Android市场上的DroidX设备上遇到了以下崩溃错误.

我认为imageCaptureUri在这种情况下不能为空.所以这不是原因.

你有什么想法？这是固件错误吗？

java.lang.NullPointerException位于com.eb.android.activity.Add活动的com.eb.android.activity.AddActivity.getBase64Receipt(AddActivity.java:193)的android.content.ContentResolver.openInputStream(ContentResolver.java:286).发布Receipt(AddActivity.java:204)at com.eb.android.activity.AddActivity.access $ 0(AddActivity.java:203)at com.eb.android.activity.AddActivity $ 1.run(AddActivity.java:50)at java .lang.Thread.run(Thread.java:1102)

---

java.lang.NullPointerException位于com.eb.android.activity.Add活动的com.eb.android.activity.AddActivity.getBase64Receipt(AddActivity.java:193)的android.content.ContentResolver.openInputStream(ContentResolver.java:288).发布Receipt(AddActivity.java:204)at com.eb.android.activity.AddActivity.access $ 0(AddActivity.java:203)at com.eb.android.activity.AddActivity $ 1.run(AddActivity.java:50)at java .lang.Thread.run(Thread.java:1096)

这是我的实施:

public class AddActivity extends Activity {

    public static final int TAKE_RECEIPT = 2;

    private Uri imageCaptureUri;

    private Runnable submitReceiptRunnable = new Runnable() {
        public void run() {
            publishReceipt();
        }
    };

    private ProgressDialog progressDialog;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.add);

        registerListeners();
    }

    public void onActivityResult(int reqCode, int resultCode, Intent data) {
        super.onActivityResult(reqCode, resultCode, data);

        switch (reqCode) {
            case (TAKE_RECEIPT):
                takeReceiptCallback(resultCode, data);
                break;
        }
    }

    private void registerListeners() {
        ImageView addReceiptButton = (ImageView) findViewById(R.id.AddReceiptButton);
        addReceiptButton.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                takePictureFromCamera();
            }
        });
    }

    private void takePictureFromCamera() {
        Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);

        imageCaptureUri = Uri.fromFile(new File(Environment.getExternalStorageDirectory(), "tmp_receipt_"
                + String.valueOf(System.currentTimeMillis()) + ".jpg"));

        intent.putExtra(android.provider.MediaStore.EXTRA_OUTPUT, imageCaptureUri);
        intent.putExtra("return-data", true);

        startActivityForResult(intent, TAKE_RECEIPT);
    }

    private void takeReceiptCallback(int resultCode, Intent data) {
        if (resultCode == Activity.RESULT_OK) {
            submitReceipt();
        }
    }

    private void submitReceipt() {
        Thread thread = new Thread(null, submitReceiptRunnable);
        thread.start();
        progressDialog = ProgressDialog.show(this, "Please wait...", "Publishing receipt ...", true);
    }

    private String getBase64Receipt() {
        try {
            InputStream inputStream = getContentResolver().openInputStream(imageCaptureUri);
            byte[] bytes = CommonUtil.getBytesFromInputStream(inputStream);
            return Base64.encodeBytes(bytes);
        } catch (IOException e) {
            Log.e(TAG, e.getMessage(), e);
        }

        return null;
    }

    private void publishReceipt() {
        String receipt = getBase64Receipt();

        ...
    }
}

Answer 1

您确定强制图像裁剪模式吗

intent.putExtra("return-data", true); 

适用于您使用的设备。如果我错了，请纠正我，但这不是安全且没有详细记录的方法。在这里您可以找到无需裁剪的工作代码示例。

更新：您面临的问题有着悠久的历史，也在SO：

/sf/ask/273327981/

我遇到的问题是相机拍摄图像后立即使用裁剪。此外，它在不同的 Android 版本之间不兼容，所以如果你让它在 1.5 上运行，它可能不会在 2.3 上运行。肯定有问题，正如 Android 开发者小组帖子中得出的结论：

http://groups.google.com/group/android-developers/browse_thread/thread/2dd647523926192c/569f36b5b28f2661?lnk=gst&q=Crop+image+intent#569f36b5b28f2661

http://groups.google.com/group/android-developers/browse_thread/thread/2dd647523926192c/dcbe5aef29eddad6?lnk=gst&q=Crop+image+intent#dcbe5aef29eddad6

http://groups.google.com/group/android-developers/browse_thread/thread/d7b6a133c164aa17/184bf3b85da2ce58?lnk=gst&q=Crop+image+intent#184bf3b85da2ce58