因此，我尝试从用户选择的图像中保存图像路径，以便当用户退出并重新打开应用程序时，图像仍然设置为背景或图像的imageView（它们都使用相同的图像路径方法）
这是我的编码（Drag_and_Drop_App.java）：
public Bitmap getThumbnail(String filename) {
Bitmap thumbnail = null;
try {
File filePath = this.getFileStreamPath(filename);
FileInputStream fi = new FileInputStream(filePath);
thumbnail = BitmapFactory.decodeStream(fi);
} catch (Exception ex) {
Log.e("getThumbnail() on internal storage", ex.getMessage());
}
return thumbnail;
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
Log.i("Drag_and_Drop_App", "requestCode: " + requestCode + ", resultCode: " + resultCode);
if(requestCode == SET_BACKGROUND && resultCode == RESULT_OK){
byte[] byteArray = data.getByteArrayExtra("myBackgroundBitmap");
Bitmap myBackground = BitmapFactory.decodeByteArray(byteArray, 0, byteArray.length);
setBackgroundImage(myBackground);
}
else if(requestCode == RESULT_ICON){
byte[] byteArray = data.getByteArrayExtra("myIconBitmap");
Bitmap myIcon = BitmapFactory.decodeByteArray(byteArray, 0, byteArray.length);
setBackgroundImageForIcon(myIcon);
Log.d("Drag_and_Drop_App", "Icon is set");
}
}
Personalize.java：
public String getPath(Uri uri) {
String[] projection = { MediaStore.Images.Media.DATA };
Cursor cursor = getContentResolver().query(uri, projection, null, null, null);
int column_index = cursor
.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
cursor.moveToFirst();
String imagePath = cursor.getString(column_index);
if(cursor != null) {
cursor.close();
}
return imagePath;
}
private void setIconImageInWidget() {
// TODO Auto-generated method stub
Log.d("Personalize", "setIconImageInWidget() called");
Intent i = getIntent();
//Convert bitmap to byte array to send back to activity
// See: http://stackoverflow.com/questions/11010386/send-bitmap-using-intent-android
scaleDownBitmapForIcon(b2, 500, this.getBaseContext());
Log.d("Personalize", "Scale Bitmap Chosen For Icon");
ByteArrayOutputStream stream = new ByteArrayOutputStream();
b2.compress(Bitmap.CompressFormat.PNG, 100, stream);
byte[]byteArray = stream.toByteArray();
i.putExtra("myIconBitmap", byteArray);
setResult(RESULT_ICON, i);
finish();
}
private void setBackgroundImageInDragAndDrop() {
Log.d("Personalize", "setBackgroundImageInDragAndDrop() called");
Intent i = getIntent();
//Convert bitmap to byte array to send back to activity
// See: http://stackoverflow.com/questions/11010386/send-bitmap-using-intent-android
scaleDownBitmap(background, 500, this.getBaseContext());
Log.d("Personalize", "Scale Bitmap Chosen");
ByteArrayOutputStream stream = new ByteArrayOutputStream();
background.compress(Bitmap.CompressFormat.PNG, 100, stream);
byte[]byteArray = stream.toByteArray();
i.putExtra("myBackgroundBitmap", byteArray);
setResult(RESULT_OK, i);
finish();
}
@Override
protected void onPause() {
SharedPreferences sp = getSharedPreferences("AppSharedPref", 1); //open shared preferences with name AppSharedPref
Editor editor = sp.edit();
editor.putString("ImagePath", selectedImagePath); //Store selectedImagePath with key "ImagePath". This key will be then used to retrieve data.
editor.commit();
super.onPause();
Log.d("Personalize", "onPause() called and selectedImagePath saved");
}
@Override
protected void onResume() {
SharedPreferences sp = getSharedPreferences("AppSharedPref", 1);
selectedImagePath = sp.getString("ImagePath", "");
super.onResume();
Log.d("Personalize", "onResume() called and images uploaded");
}
public boolean saveImageToInternalStorage(Bitmap image) {
try {
FileOutputStream fos = this.openFileOutput("desiredFilename.png", Context.MODE_PRIVATE);
image.compress(Bitmap.CompressFormat.PNG, 100, fos);
fos.close();
return true;
} catch (Exception e) {
return false;
}
}
问题是这不起作用，当我重新打开应用程序时，背景未使用之前选择的图像进行设置。
答案 0 :(得分：1)
当您从sharedpref onResume（）获取图像路径时，如果selectedPath不为null，请尝试将该图像添加为背景。
@Override
protected void onResume() {
SharedPreferences sp = getSharedPreferences("AppSharedPref", 1);
selectedImagePath = sp.getString("ImagePath", "");
super.onResume();
Log.d("Personalize", "onResume() called and images uploaded");
Log.d("Personalize", "Now set the image as background");
background = getAndDecodeImage(selectedImagePath);
if(background != null){
image.setImageBitmap(background);
}
}
答案 1 :(得分：0)
我在Github上创建了一个简单的应用程序来演示这个想法，如果你想遵循：
private ImageView mImage;
private Uri mImageUri;
public void imageSelect() {
Intent intent;
if (Build.VERSION.SDK_INT < 19) {
intent = new Intent(Intent.ACTION_GET_CONTENT);
} else {
intent = new Intent(Intent.ACTION_OPEN_DOCUMENT);
intent.addCategory(Intent.CATEGORY_OPENABLE);
}
intent.setType("image/*");
startActivityForResult(Intent.createChooser(intent, "Select Picture"),
PICK_IMAGE_REQUEST);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
// Check which request we're responding to
if (requestCode == PICK_IMAGE_REQUEST) {
// Make sure the request was successful
if (resultCode == RESULT_OK) {
// The user picked a image.
// The Intent's data Uri identifies which item was selected.
if (data != null) {
// This is the key line item, URI specifies the name of the data
mImageUri = data.getData();
// Saves image URI as string to Default Shared Preferences
SharedPreferences preferences =
PreferenceManager.getDefaultSharedPreferences(this);
SharedPreferences.Editor editor = preferences.edit();
editor.putString("image", String.valueOf(mImageUri));
editor.commit();
// Sets the ImageView with the Image URI
mImage.setImageURI(mImageUri);
mImage.invalidate();
}
}
}
}
SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(this);
String mImageUri = preferences.getString("image", null);
if (mImageUri != null) {
mImage.setImageURI(Uri.parse(mImageUri));
} else {
// uses a default image
mImage.setImageResource(R.drawable.ic_launcher);
}
就是这样！现在，当用户退出并重新打开应用时，图片仍然会设置为imageView。