如何在Android中从图库中选择多个图像？

在上一篇文章中，我们已经看到了如何在Android中从库中选择图像，但是在大多数情况下，当我们在whatsapp上发布状态或在Facebook或instagram上发布帖子时，我们选择了多个图像。因此，在本文中，已逐步讨论了如何从图库中选择一个或多个图像，然后我们将看到所选图像的总数。下面提供了一个示例视频，以使您对本文中的工作有个大概的了解。注意，我们将使用Java语言实现该项目。

分步实施

步骤1：创建一个新项目

要在Android Studio中创建新项目，请参阅如何在Android Studio中创建/启动新项目。请注意，选择Java作为编程语言。

步骤2：使用AndroidManifest.xml文件

要将数据添加到Firebase，我们必须授予访问Internet的权限。要添加这些权限，请导航至应用程序> AndroidManifest.xml，然后在该文件内向其添加以下权限。

步骤3：使用activity_main.xml文件

导航到应用程序> res>布局> activity_main.xml，然后将以下代码添加到该文件中。以下是activity_main.xml文件的代码。

步骤4：使用MainActivity。 Java文件

转到MainActivity。 Java文件并参考以下代码。下面是MainActivity的代码。 Java文件。在代码内部添加了注释，以更详细地了解代码。

Java

import android.content.ClipData;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageSwitcher;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.ViewSwitcher;
  
import androidx.appcompat.app.AppCompatActivity;
  
import java.util.ArrayList;
import java.util.List;
  
public class MainActivity extends AppCompatActivity {
  
    Button select, previous, next;
    ImageSwitcher imageView;
    int PICK_IMAGE_MULTIPLE = 1;
    String imageEncoded;
    TextView total;
    ArrayList mArrayUri;
    int position = 0;
    List imagesEncodedList;
  
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        select = findViewById(R.id.select);
        total = findViewById(R.id.text);
        imageView = findViewById(R.id.image);
        previous = findViewById(R.id.previous);
        mArrayUri = new ArrayList();
          
        // showing all images in imageswitcher
        imageView.setFactory(new ViewSwitcher.ViewFactory() {
            @Override
            public View makeView() {
                ImageView imageView1 = new ImageView(getApplicationContext());
                return imageView1;
            }
        });
        next = findViewById(R.id.next);
          
        // click here to select next image
        next.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (position < mArrayUri.size() - 1) {
                    // increase the position by 1
                    position++;
                    imageView.setImageURI(mArrayUri.get(position));
                } else {
                    Toast.makeText(MainActivity.this, "Last Image Already Shown", Toast.LENGTH_SHORT).show();
                }
            }
        });
          
        // click here to view previous image
        previous.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (position > 0) {
                    // decrease the position by 1
                    position--;
                    imageView.setImageURI(mArrayUri.get(position));
                }
            }
        });
  
        imageView = findViewById(R.id.image);
          
        // click here to select image
        select.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                
                // initialising intent
                Intent intent = new Intent();
                  
                // setting type to select to be image
                intent.setType("image/*");
                  
                // allowing multiple image to be selected
                intent.putExtra(Intent.EXTRA_ALLOW_MULTIPLE, true);
                intent.setAction(Intent.ACTION_GET_CONTENT);
                startActivityForResult(Intent.createChooser(intent, "Select Picture"), PICK_IMAGE_MULTIPLE);
            }
        });
    }
      
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        // When an Image is picked
        if (requestCode == PICK_IMAGE_MULTIPLE && resultCode == RESULT_OK && null != data) {
            // Get the Image from data
            if (data.getClipData() != null) {
                ClipData mClipData = data.getClipData();
                int cout = data.getClipData().getItemCount();
                for (int i = 0; i < cout; i++) {
                    // adding imageuri in array
                    Uri imageurl = data.getClipData().getItemAt(i).getUri();
                    mArrayUri.add(imageurl);
                }
                // setting 1st selected image into image switcher
                imageView.setImageURI(mArrayUri.get(0));
                position = 0;
            } else {
                Uri imageurl = data.getData();
                mArrayUri.add(imageurl);
                imageView.setImageURI(mArrayUri.get(0));
                position = 0;
            }
        } else {
            // show this if no image is selected
            Toast.makeText(this, "You haven't picked Image", Toast.LENGTH_LONG).show();
        }
    }
}

输出：