Android相机捕获活动返回空Uri [英] Android camera capture activity returns null Uri

问题描述

此代码之前曾在三星上运行，但现在我将Nexus One与Android 2.3.6配合使用，只要我拍照并单击确定"或从图库中选择照片，它就会崩溃. Stacktrace在Uri上显示一个空指针异常.
我激活相机的代码如下:

This code worked on samsung before but now that i'm using Nexus One with Android 2.3.6, it's crashing as soon as I take a picture and click ok or choose a photo from gallery. Stacktrace shows a null pointer exception on the Uri.
My code for the activating the camera is as follows:

public void activateCamera(View view){      
    Intent i = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    // start the image capture Intent
    startActivityForResult(i, CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE);
}

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

    super.onActivityResult(requestCode, resultCode, data);

    if ((requestCode == CHOOSE_IMAGE_ACTIVITY_REQUEST_CODE  || requestCode == CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE) 
        && resultCode == RESULT_OK && null != data) {

        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();

        Bitmap bits = null;

        BitmapFactory.Options options = new BitmapFactory.Options();

        options.inSampleSize = inSampleSize;

        try {
            bits = BitmapFactory.decodeStream(new FileInputStream(picturePath),null,options);
        } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
        }

任何想法可能是什么问题? 谢谢！

Any idea what could be the problem? Thanks!

推荐答案

您必须告诉相机保存图片的位置并自己记住uri:

You have to tell the camera, where to save the picture and remeber the uri yourself:

private Uri mMakePhotoUri;

private File createImageFile() {
    // return a File object for your image.
}

private void makePhoto() {
    try {
        File f = createImageFile();
        Intent i = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
        mMakePhotoUri = Uri.fromFile(f);
        i.putExtra(MediaStore.EXTRA_OUTPUT, mMakePhotoUri);
        startActivityForResult(i, REQUEST_MAKE_PHOTO);
    } catch (IOException e) {
        Log.e(TAG, "IO error", e);
        Toast.makeText(getActivity(), R.string.error_writing_image, Toast.LENGTH_LONG).show();
    }
}

@Override
public void onActivityResult(final int requestCode, final int resultCode, final Intent data) {
    switch (requestCode) {
        case REQUEST_MAKE_PHOTO:
            if (resultCode == Activity.RESULT_OK) {
                // do something with mMakePhotoUri
            }
            return;
        default: // do nothing
            super.onActivityResult(requestCode, resultCode, data);
    }
}

您应该使用onCreate()和onSaveInstanceState()在实例状态中保存mMakePhotoUri的值.

You should save the value of mMakePhotoUri over instance states withing onCreate() and onSaveInstanceState().

这篇关于Android相机捕获活动返回空Uri的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！