Android開発者のガイドに従ってカメラを機能させましたが、null例外があることを何も忘れていません
コードは次のとおりです。
import java.io.File;
import java.text.SimpleDateFormat;
import java.util.Date;
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 android.util.Log;
import android.widget.Toast;
public class MakePhotoActivity extends Activity {
public static final int MEDIA_TYPE_IMAGE = 1;
public static final int MEDIA_TYPE_VIDEO = 2;
/** Create a file Uri for saving an image or video */
private 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()){
if (! mediaStorageDir.mkdirs()){
Log.d("MyCameraApp", "failed to create directory");
return null;
}else{
Log.d("MyCameraApp", "success to create directory");
}
}
// 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 if(type == MEDIA_TYPE_VIDEO) {
mediaFile = new File(mediaStorageDir.getPath() + File.separator +
"VID_"+ timeStamp + ".mp4");
} else {
return null;
}
return mediaFile;
}
private static final int CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE = 100;
private Uri fileUri;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.camera_tuto);
// create Intent to take a picture and return control to the calling application
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
fileUri = getOutputMediaFileUri(MEDIA_TYPE_IMAGE); // create a file to save the image
intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri); // set the image file name
// start the image capture Intent
startActivityForResult(intent, CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE);
}
@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
Toast.makeText(this, "Image saved to:\n" +
data.getData(), Toast.LENGTH_LONG).show();
} else if (resultCode == RESULT_CANCELED) {
// User cancelled the image capture
} else {
// Image capture failed, advise user
}
}
}
}
写真を撮るときの例外は次のとおりです。
10-10 07:46:12.104: E/AndroidRuntime(1279): java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=100, result=-1, data=null} to activity {com.example.android_app_test/com.example.android_app_test.MakePhotoActivity}: java.lang.NullPointerException
この問題を解決するにはどうすればよいですか
編集** * *
エラーの全文は次のとおりです。
10-10 09:02:50.434: D/AndroidRuntime(1735): Shutting down VM
10-10 09:02:50.434: W/dalvikvm(1735): threadid=1: thread exiting with uncaught exception (group=0x414c4700)
10-10 09:02:50.633: E/AndroidRuntime(1735): FATAL EXCEPTION: main
10-10 09:02:50.633: E/AndroidRuntime(1735): java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=100, result=-1, data=null} to activity {com.example.android_app_test/com.example.android_app_test.MakePhotoActivity}: java.lang.NullPointerException
10-10 09:02:50.633: E/AndroidRuntime(1735): at android.app.ActivityThread.deliverResults(ActivityThread.java:3367)
10-10 09:02:50.633: E/AndroidRuntime(1735): at android.app.ActivityThread.handleSendResult(ActivityThread.java:3410)
10-10 09:02:50.633: E/AndroidRuntime(1735): at android.app.ActivityThread.access$1100(ActivityThread.java:141)
10-10 09:02:50.633: E/AndroidRuntime(1735): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1304)
10-10 09:02:50.633: E/AndroidRuntime(1735): at android.os.Handler.dispatchMessage(Handler.java:99)
10-10 09:02:50.633: E/AndroidRuntime(1735): at android.os.Looper.loop(Looper.java:137)
10-10 09:02:50.633: E/AndroidRuntime(1735): at android.app.ActivityThread.main(ActivityThread.java:5103)
10-10 09:02:50.633: E/AndroidRuntime(1735): at java.lang.reflect.Method.invokeNative(Native Method)
10-10 09:02:50.633: E/AndroidRuntime(1735): at java.lang.reflect.Method.invoke(Method.java:525)
10-10 09:02:50.633: E/AndroidRuntime(1735): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
10-10 09:02:50.633: E/AndroidRuntime(1735): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
10-10 09:02:50.633: E/AndroidRuntime(1735): at dalvik.system.NativeStart.main(Native Method)
10-10 09:02:50.633: E/AndroidRuntime(1735): Caused by: java.lang.NullPointerException
10-10 09:02:50.633: E/AndroidRuntime(1735): at com.example.android_app_test.MakePhotoActivity.onActivityResult(MakePhotoActivity.java:88)
10-10 09:02:50.633: E/AndroidRuntime(1735): at android.app.Activity.dispatchActivityResult(Activity.java:5322)
10-10 09:02:50.633: E/AndroidRuntime(1735): at android.app.ActivityThread.deliverResults(ActivityThread.java:3363)
10-10 09:02:50.633: E/AndroidRuntime(1735): ... 11 more