Question

我有以下代码。我从片段中的库中将图像设置为ImageView。问题是当我更改片段并再次使用ImageView返回片段时，它具有默认图像，而不是我设置的图像。

pattern

我有public class Fragment_user extends Fragment { private static final int SELECT_PICTURE = 1; private String selectedImagePath=null; private ImageView img; @Override public View onCreateView( LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){ View rootView = inflater.inflate(R.layout.fragment_user, container, false); //if (savedInstanceState == null){ img = (ImageView)rootView.findViewById(R.id.userImage); //}else{ //Bitmap bitmap = (Bitmap) savedInstanceState.getParcelable("bitmap"); //img.setImageBitmap(bitmap); //} img.setOnClickListener(new OnClickListener() { public void onClick(View arg0) { Intent intent = new Intent(); intent.setType("image/*"); intent.setAction(Intent.ACTION_GET_CONTENT); startActivityForResult(Intent.createChooser(intent,"Select Picture"), SELECT_PICTURE); } }); return rootView; } public void onActivityResult(int requestCode, int resultCode, Intent data) { if (resultCode == MainActivity.RESULT_OK) { if (requestCode == SELECT_PICTURE) { Uri selectedImageUri = data.getData(); selectedImagePath = getPath(selectedImageUri); System.out.println("Image Path : " + selectedImagePath); img.setImageURI(selectedImageUri); } } } public String getPath(Uri uri) { String[] projection = { MediaStore.Images.Media.DATA }; Cursor cursor = getActivity().getContentResolver().query(uri, projection, null, null, null); if (cursor == null) return null; int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA); cursor.moveToFirst(); String s=cursor.getString(column_index); cursor.close(); return s; } @Override public void onSaveInstanceState(Bundle outState) { super.onSaveInstanceState(outState); // Save the image bitmap into outState Bitmap bitmap = ((BitmapDrawable)img.getDrawable()).getBitmap(); outState.putParcelable("bitmap", bitmap); } @Override public void onActivityCreated(Bundle savedInstanceState) { super.onActivityCreated(savedInstanceState); // Read the bitmap from the savedInstanceState and set it to the ImageView if (savedInstanceState != null){ Bitmap bitmap = (Bitmap) savedInstanceState.getParcelable("bitmap"); img.setImageBitmap(bitmap); } } }方法将选定的图像保存到位图，onSaveInstanceState方法将图像设置回ImageView，当我回到Fragment时。但这不起作用。有帮助吗？提前致谢

Answer 1

这是因为你的片段根据Fragments Lifecycle丢失了它的视图。要解决您的问题，请执行下一步操作：

创建全局变量private Uri mSelectedImageUri;

使用此变量代替您的本地Uri selectedImageUri：

if (requestCode == SELECT_PICTURE) {
    mSelectedImageUri = data.getData();
    selectedImagePath = getPath(mSelectedImageUri);
    System.out.println("Image Path : " + selectedImagePath);
    img.setImageURI(mSelectedImageUri);
}

在此行img = (ImageView)rootView.findViewById(R.id.userImage);下面添加检查：
```
if (mSelectedImageUri != null) {
    img.setImageURI(mSelectedImageUri);
}
```

更改片段时，在片段上的ImageView中保留图像

1 个答案: