Question

好的，所以当我第一次上传图像时就可以了，但是在上传第二张图像之后，先前的图像会从存储中删除。我喜欢我用来上传图片的代码。

我已经链接了整个活动类，该类负责将文件上传到Firebase Storage。尝试为图像使用其他名称（uid），但无济于事。

import android.content.Intent;
import android.net.Uri;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;

import com.google.android.gms.tasks.Continuation;
import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.storage.FirebaseStorage;
import com.google.firebase.storage.StorageReference;
import com.google.firebase.storage.StorageTask;
import com.google.firebase.storage.UploadTask;
import com.squareup.picasso.Picasso;

import java.util.UUID;

public class ActivityUltimateMemeWorks extends AppCompatActivity {

    private static final int PICK_IMAGE_REQUEST = 1;

    private Button mButtonChooseImage;
    private Button mButtonUpload;
    private TextView mTextViewShowUploads;
    private EditText mEditTextFileName;
    private ImageView mImageView;
    private ProgressBar mProgressBar;
    private StorageReference mStorageRef;
    private DatabaseReference mDatabaseRef;
    private StorageTask mUploadTask;
    private String imageIdentifier;


    private Uri mImageUri;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_ultimate_meme_works);

        mButtonChooseImage = findViewById(R.id.button_choose_image);
        mButtonUpload = findViewById(R.id.button_upload);
        mTextViewShowUploads = findViewById(R.id.text_view_show_uploads);
        mEditTextFileName = findViewById(R.id.edit_text_file_name);
        imageIdentifier = UUID.randomUUID().toString() + ".png";
        mImageView = findViewById(R.id.image_view);
        mProgressBar = findViewById(R.id.progress_bar);
        mStorageRef = FirebaseStorage.getInstance().getReference("UMWuploads").child("images").child(imageIdentifier);
        mDatabaseRef = FirebaseDatabase.getInstance().getReference("UMWuploads");


        mButtonChooseImage.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                openFileChooser();
            }
        });

        mButtonUpload.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (mUploadTask != null && mUploadTask.isInProgress()) {
                    Toast.makeText(ActivityUltimateMemeWorks.this, "Upload in progress", Toast.LENGTH_SHORT).show();
                } else {
                    uploadFile();
                }

            }
        });

        mTextViewShowUploads.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                openImagesActivity();

            }
        });
    }

    private void openFileChooser() {
        Intent intent = new Intent();
        intent.setType("image/*");
        intent.setAction(Intent.ACTION_GET_CONTENT);
        startActivityForResult(intent, PICK_IMAGE_REQUEST);
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        if (requestCode == PICK_IMAGE_REQUEST && resultCode == RESULT_OK
                && data != null && data.getData() != null) {
            mImageUri = data.getData();

            Picasso.get().load(mImageUri).into(mImageView);
        }
    }

    private void uploadFile() {

        if (mImageUri != null) {
            mStorageRef.putFile(mImageUri).continueWithTask(new Continuation<UploadTask.TaskSnapshot, Task<Uri>>() {
                @Override
                public Task<Uri> then(@NonNull Task<UploadTask.TaskSnapshot> task) throws Exception {
                    if (!task.isSuccessful()) {
                        throw task.getException();
                    }
                    return mStorageRef.getDownloadUrl();
                }
            }).addOnCompleteListener(new OnCompleteListener<Uri>() {
                @Override
                public void onComplete(@NonNull Task<Uri> task) {
                    if (task.isSuccessful()) {
                        Uri downloadUri = task.getResult();
                        Toast.makeText(ActivityUltimateMemeWorks.this, "uploading", Toast.LENGTH_SHORT).show();
                        Log.e("hello", "then: " + downloadUri.toString());


                        Upload upload = new Upload(mEditTextFileName.getText().toString().trim(),
                                downloadUri.toString());

                        mDatabaseRef.push().setValue(upload);
                    } else {
                        Toast.makeText(ActivityUltimateMemeWorks.this, "upload failed: " + task.getException().getMessage(), Toast.LENGTH_SHORT).show();
                    }
                }
            });
        }


    }
    private void openImagesActivity() {
        Intent intent = new Intent(this, ImagesActivity.class);
        startActivity(intent);
    }
}

Answer 1

尝试此操作，它将在每次上传时更改文件名：

private void uploadFile() {
    imageIdentifier = UUID.randomUUID().toString() + ".png";
    mStorageRef = FirebaseStorage.getInstance().getReference("UMWuploads").child("images").child(imageIdentifier);
    if (mImageUri != null) {
        mStorageRef.putFile(mImageUri).continueWithTask(new Continuation<UploadTask.TaskSnapshot, Task<Uri>>() {
            @Override
                public Task<Uri> then(@NonNull Task<UploadTask.TaskSnapshot> task) throws Exception {
                    if (!task.isSuccessful()) {
                        throw task.getException();
                    }
                    return mStorageRef.getDownloadUrl();
                }
        }).addOnCompleteListener(new OnCompleteListener<Uri>() {
            @Override
                public void onComplete(@NonNull Task<Uri> task) {
                    if (task.isSuccessful()) {
                        Uri downloadUri = task.getResult();
                        Toast.makeText(ActivityUltimateMemeWorks.this, "uploading", Toast.LENGTH_SHORT).show();
                        Log.e("hello", "then: " + downloadUri.toString());
                        Upload upload = new Upload(mEditTextFileName.getText().toString().trim(),
                        downloadUri.toString());
                        mDatabaseRef.push().setValue(upload);
                    } else {
                        Toast.makeText(ActivityUltimateMemeWorks.this, "upload failed: " + task.getException().getMessage(), Toast.LENGTH_SHORT).show();
                    }
                }
        });
    }
}

现在让我解释一下为什么它对您不起作用。如果您看到自己在imageIdentifier中分配了onCreateView的代码，则意味着只有当用户启动应用程序时，它才会重新加载，而他尝试上载图片时并非总是如此。因此，当他单击按钮或调用功能时，您需要重置图像的名称。所以只要将其放在函数中，就意味着他单击了Upload。函数将被调用并重新调用值，并返回新值。

FireBase Storage Android中的新图像将删除以前上传的图像

1 个答案: