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Mein Ziel ist es, das zuletzt gewählte Bild in ImageView zu behalten, nachdem eine App geschlossen (zerstört) und dann wieder geöffnet wurde.Laden des zuletzt ausgewählten Bildes in ImageView nach erneuter Eingabe der App
ich versuchte, in SharedPreference speichern Bitmap zu laden „(How can I store images using sharedpreference in android?), dann wird in SharedPreferences in Bitmap ich versuchte Pfad zu speichern und laden, es Picasso verwendet: (Picasso Load image from filesystem) und versuchte, sie durch Hindurchführen des Wertes BitmapFactory.decodeFile(completePath); zu laden, wie Sie können in meinem Code sehen
Wie auch immer der Ausgang ist immer das gleiche;. ich bin ein Nullpointer bekommen
ich bin neu in Android und Programmierung im allgemeinen so meine unordentlichen Code vergeben
private String picturePass;
private ImageView imageView;
private Bitmap picBitmap;
private boolean yes;
private static final int SELECT_PICTURE = 1;
private static final String SAVE_NAME = "MyFile";)
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main_activity_page);
if (savedInstanceState != null) {
savedInstanceState.get("path");
}
//loading
SharedPreferences preferences = getSharedPreferences(SAVE_NAME, MODE_PRIVATE);
//boolean to check if Image was chosen
yes = preferences.getBoolean("yes", true);
if(yes){
picturePass = preferences.getString("path", null);
String completePath = picturePass;
//just to check the content
Toast.makeText(this, completePath, Toast.LENGTH_LONG).show();
File file = new File(completePath);
if (file.exists()) {
picBitmap = BitmapFactory.decodeFile(completePath);
imageView.setImageBitmap(picBitmap);
}
}
}
//Choosing a picture from gallery
public void onClickImage(View view) {
Intent intent = new Intent(Intent.ACTION_PICK, MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(intent, SELECT_PICTURE);
yes = true;
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == SELECT_PICTURE && resultCode == RESULT_OK && null != data) {
//The only way I maneged to get the file path, that's a messy part
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();
//Setting picture in imageView
if (selectedImage != null) {
try {
Bitmap bitmap = MediaStore.Images.Media.getBitmap(this.getContentResolver(), selectedImage);
imageView = (ImageView) findViewById(R.id.imageView);
imageView.setImageBitmap(bitmap);
picBitmap = bitmap;
//Tried to use Environment.getExternalStorageDirectory().getAbsolutePath() + imageName with no success
//File f = new File(picturePath);
//String imageName = f.getName();
//picturePass = imageName;
picturePass = picturePath;
//Saving image path
//just too check the content
Toast.makeText(this, picturePath, Toast.LENGTH_LONG).show();
SharedPreferences.Editor editor = getSharedPreferences(SAVE_NAME, MODE_PRIVATE).edit();
editor.putString("path", picturePass);
editor.putBoolean("yes", true);
editor.commit();
} catch (Exception ex) {
ex.printStackTrace();
}
}
} else {
super.onActivityResult(requestCode, resultCode, data);
}
}
@Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putString("path", picturePass);
}
}
08-29 19:05:46.263 16436-16436/com.amberapply.vitaliy.iloveyou E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.amberapply.vitaliy.iloveyou, PID: 16436
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.amberapply.vitaliy.iloveyou/com.amberapply.vitaliy.iloveyou.MainActivityPage}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ImageView.setImageBitmap(android.graphics.Bitmap)' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2325)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387)
at android.app.ActivityThread.access$800(ActivityThread.java:151)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5258)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:940)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:735)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ImageView.setImageBitmap(android.graphics.Bitmap)' on a null object reference
at com.amberapply.vitaliy.iloveyou.MainActivityPage.onCreate(MainActivityPage.java:60)
at android.app.Activity.performCreate(Activity.java:6005)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2278)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387)
at android.app.ActivityThread.access$800(ActivityThread.java:151)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5258)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:940)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:735)
"MainActivityPage.java:60" Was ist Zeile 60 in 'MainActivityPage.java'? –