Question

您好我开始在Android中使用相机，就像它可以从here获得一样简单。

问题是在我拍摄照片后，由于某种原因，文件的uri只是空的。

步骤：

我跑了takePhoto() func，手机的标准相机应用启动，我拍了照片，我保存了。
我的应用程序运行onActivityResult(...) func，因为它从摄像机返回控件，文件的uri只是空。

代码：

在我的活动中：

/**
 * Intent code for capturing a photo
 */
private static final int CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE = 100;

/**
 * 
 * Takes a photo
 */
public void takePhoto() {
    // create Intent to take a picture and return control to the calling application
    Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    fileUri = CameraHelper.getOutputMediaFileUri(CameraHelper.MEDIA_TYPE_IMAGE); // create a file to save the image
    Log.i("PHOTO", "file uri is: " + fileUri.toString());
    intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri); // set the image file name
    // start the image capture Intent
    startActivityForResult(intent, CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE);
}
/**
 * 
 * After taking the photo...
 */
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE) {
        if (resultCode == RESULT_OK) {
            // Image captured and saved to fileUri specified in the Intent
            if (data == null) {
                Toast.makeText(this, "Camera error: data is null!", Toast.LENGTH_LONG).show();
                Log.i("PHOTO", "Camera error: data is null!");
                // Error is here, data does not contains the uri.
            }
            else {
                Toast.makeText(this, "Image saved to:\n" + data.getData(), Toast.LENGTH_LONG).show();
                Log.i("PHOTO", "Image saved to:\n" + data.getData());
            }
        }
        else if (resultCode == RESULT_CANCELED) {
            // User cancelled the image capture
        }
        else {
            // Image capture failed, advise user
        }
    }
}

CameraHelper类：

public class CameraHelper {

public static final int MEDIA_TYPE_IMAGE = 1;



/** Create a file Uri for saving an image or video */
public static Uri getOutputMediaFileUri(int type) {
    return Uri.fromFile(getOutputMediaFile(type));
}
/** Create a File for saving an image or video */
private static File getOutputMediaFile(int type) {
    // To be safe, you should check that the SDCard is mounted
    // using Environment.getExternalStorageState() before doing this.
    File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), "MyCameraApp");
    // This location works best if you want the created images to be shared
    // between applications and persist after your app has been uninstalled.
    // Create the storage directory if it does not exist
    if (!mediaStorageDir.exists()) {

        Log.i("PHOTO", "directory is not exists yet!");
        if (!mediaStorageDir.mkdirs()) {
            Log.d("MyCameraApp", "failed to create directory");
            return null;
        }
        else {
            Log.i("PHOTO", "just made directory: " + mediaStorageDir.getAbsolutePath());
        }
    }
    else {
        Log.i("PHOTO", "directory is already exist: " + mediaStorageDir.getAbsolutePath());
    }
    // Create a media file name
    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").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;
}

}

日志输出：

01-13 16:15:37.485: I/PHOTO(6818): directory is already exist: /storage/sdcard0/Pictures/MyCameraApp
01-13 16:15:37.495: I/PHOTO(6818): file uri is: file:///storage/sdcard0/Pictures/MyCameraApp/IMG_20150113_161537.jpg


01-13 16:16:13.482: I/PHOTO(6818): Camera error: data is null!

所有图片都在文件夹中：Pictures/MyCameraApp但onActivityResult(...)不包含数据字段中的uri。

我做错了什么？

用相机拍照，onActivityResult不包含媒体（照片）uri

0 个答案: