如何 select 從設備的圖庫中獲取圖像並將其顯示在圖像視圖上

Question

我目前在我的 android 應用程序的主頁上有三個按鈕。 一個打開相機，一個從圖像中檢測文本，但我希望第三個按鈕打開畫廊，讓用戶從他們的設備中訪問 select 圖像。

MainActivity.java

package com.mvsolutions.snap;

import android.os.Bundle;

import com.google.android.material.floatingactionbutton.FloatingActionButton;
import com.google.android.material.snackbar.Snackbar;

import android.view.View;

import androidx.navigation.NavController;
import androidx.navigation.Navigation;
import androidx.navigation.ui.AppBarConfiguration;
import androidx.navigation.ui.NavigationUI;

import com.google.android.material.navigation.NavigationView;

import androidx.drawerlayout.widget.DrawerLayout;

import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;

import android.view.Menu;

public class MainActivity extends AppCompatActivity {

    private AppBarConfiguration mAppBarConfiguration;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        FloatingActionButton fab = findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
            }
        });
        DrawerLayout drawer = findViewById(R.id.drawer_layout);
        NavigationView navigationView = findViewById(R.id.nav_view);
        // Passing each menu ID as a set of Ids because each menu should be considered as top level destinations.
        mAppBarConfiguration = new AppBarConfiguration.Builder(
                R.id.nav_home, R.id.nav_gallery, R.id.nav_slideshow, R.id.nav_tools, R.id.nav_share, R.id.nav_send)
                .setDrawerLayout(drawer)
                .build();
        NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment);
        NavigationUI.setupActionBarWithNavController(this, navController, mAppBarConfiguration);
        NavigationUI.setupWithNavController(navigationView, navController);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onSupportNavigateUp() {
        NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment);
        return NavigationUI.navigateUp(navController, mAppBarConfiguration) || super.onSupportNavigateUp();
    }
}

首頁Fragment.java

package com.mvsolutions.snap.ui.home;

import android.content.Intent;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.provider.MediaStore;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;

import androidx.annotation.Nullable;
import androidx.annotation.NonNull;
import androidx.fragment.app.Fragment;
import androidx.lifecycle.Observer;
import androidx.lifecycle.ViewModelProviders;

import com.google.android.gms.tasks.OnFailureListener;
import com.google.android.gms.tasks.OnSuccessListener;
import com.google.firebase.ml.vision.FirebaseVision;
import com.google.firebase.ml.vision.common.FirebaseVisionImage;
import com.google.firebase.ml.vision.text.FirebaseVisionText;
import com.google.firebase.ml.vision.text.FirebaseVisionTextDetector;
import com.mvsolutions.snap.R;

import java.util.List;

import static android.app.Activity.RESULT_OK;

public class HomeFragment extends Fragment {

    private HomeViewModel homeViewModel;

    private ImageView imageView;
    private Button captureImageButton, detectButton;
    private Bitmap imageBitmap;
    private TextView capturedTextView;
    static final int REQUEST_IMAGE_CAPTURE = 1;

    public View onCreateView(@NonNull LayoutInflater inflater,
                             ViewGroup container, Bundle savedInstanceState) {
        homeViewModel = ViewModelProviders.of(this).get(HomeViewModel.class);
        View root = inflater.inflate(R.layout.fragment_home, container, false);
        imageView = root.findViewById(R.id.home_image_view_img);
        capturedTextView = root.findViewById(R.id.home_text_view_txt);
        captureImageButton = root.findViewById(R.id.button_capture_image_btn);
        detectButton = root.findViewById(R.id.button_detect_text_btn);


        captureImageButton.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                dispatchTakePictureIntent();
            }
        });
        detectButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                detectTextFromImage();
            }
        });
        return root;
    }

    private void placeholder() {
         //ignore this
    }

    private void detectTextFromImage() {

        capturedTextView.setText("");
        FirebaseVisionImage firebaseVisionImage = FirebaseVisionImage.fromBitmap(imageBitmap);
        FirebaseVisionTextDetector visionTextDetector = FirebaseVision.getInstance().getVisionTextDetector();
        visionTextDetector.detectInImage(firebaseVisionImage).addOnSuccessListener(new OnSuccessListener<FirebaseVisionText>() {
            @Override
            public void onSuccess(FirebaseVisionText firebaseVisionText) {
                List<FirebaseVisionText.Block> textBlocks = firebaseVisionText.getBlocks();
                if(textBlocks.size() == 0){
                    Toast.makeText(getContext(), "No Text Found", Toast.LENGTH_SHORT).show();
                }else{
                    for(FirebaseVisionText.Block block : textBlocks){
                        String text = block.getText();
                        capturedTextView.setText(capturedTextView.getText() + " " + text);
                    }
                }
            }
        }).addOnFailureListener(new OnFailureListener() {
            @Override
            public void onFailure(@NonNull Exception e) {
                Toast.makeText(getContext(), "Something went wrong", Toast.LENGTH_SHORT).show();
                Log.d("Error", e.getMessage());
            }
        });
    }

    private void pickImage() {

    }

    private void dispatchTakePictureIntent() {
        Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
        if (takePictureIntent.resolveActivity(getActivity().getPackageManager()) != null) {
            startActivityForResult(takePictureIntent, REQUEST_IMAGE_CAPTURE);
        }
    }


    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == REQUEST_IMAGE_CAPTURE && resultCode == RESULT_OK) {
            Bundle extras = data.getExtras();
            imageBitmap = (Bitmap) extras.get("data");
            imageView.setImageBitmap(imageBitmap);
        }
    }
}

我想要 HomeFragment.java 文件中 go 的方法。 我的最終目標是使用 select 按鈕從設備上的圖庫中獲取圖像並將其顯示在 HomeFragment.java 中的 imageview

Answer 1

Android P（api 28）及以后版本，需要使用ImageDecoder.Source引用要解碼的數據。 要解碼只需使用ImageDecoder.decodeBitmap (source) 。

要恢復和解碼以前版本中的圖像，您必須使用MediaStore 。

你的onActivityResult應該是這樣的

  @Override
  public void onActivityResult(int requestCode, int resultCode, Intent data) {
  super.onActivityResult(requestCode, resultCode, data);
  
    if (requestCode == REQUEST_IMAGE_CAPTURE && resultCode == RESULT_OK) {
      Uri uri = data.getData();
      
      try {
          assert uri != null;
          if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
          
              ImageDecoder.Source source = ImageDecoder.createSource(this.getContentResolver(), uri);
              imageBitmap = ImageDecoder.decodeBitmap(source);
              
          } else {
              imageBitmap = MediaStore.Images.Media.getBitmap(getContentResolver(), uri);
          }
          imageView.setImageBitmap(imageBitmap);
      } catch (IOException e) {
          e.printStackTrace();
      }
    }
  }

我希望這對您有所幫助^ - ^

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有關詳細信息，請參閱ImageDecoder MediaStore

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