logo标签列表

从相机拍摄并上传到Firebase的图像捕获

androidfirebaseandroid-camerafirebase-storage
3
我正在开发一个简单的博客应用程序，允许用户从手机相册上传照片和描述到Firebase服务器。我正在尝试修改我的当前项目，以允许用户通过相机拍摄照片并将其上传到Firebase服务器。
目前，我能够将我拍摄的图像显示在imagebutton中，但是我无法将我的图像发布到Firebase服务器（“提交帖子”按钮不响应我的onclick函数）。
我怀疑我的startPosting()函数存在某些错误或者我没有正确编码图像？请帮忙。
package simpleblog2.emily.example.com.simpleblog2;

import android.app.ProgressDialog;
import android.content.ContentProvider;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.media.Image;
import android.net.Uri;
import android.os.Environment;
import android.provider.MediaStore;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.Toast;

import com.google.android.gms.tasks.OnSuccessListener;
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.UploadTask;
import com.squareup.picasso.Picasso;

import com.theartofdev.edmodo.cropper.CropImage;

import java.io.File;


public class PostActivity extends AppCompatActivity {

    private ImageButton mSelectImage;
    private EditText mPostTitle;
    private EditText mPostDesc;
    private Button mSubmitBtn;
    private ProgressDialog mProgress;
    private DatabaseReference mDatabase;

    private Uri mImageUri = null;

    private static final int GALLERY_REQUEST = 1;

    private static final int CAMERA_REQUEST_CODE = 1;

    private StorageReference mStorage;

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

        mStorage = FirebaseStorage.getInstance().getReference();
        mDatabase = FirebaseDatabase.getInstance().getReference().child("Blog");

        mSelectImage = (ImageButton) findViewById(R.id.imageSelect);
        mPostTitle = (EditText) findViewById(R.id.titleField);
        mPostDesc = (EditText) findViewById(R.id.descField);
        mSubmitBtn = (Button) findViewById(R.id.submitBtn);

        mProgress = new ProgressDialog(this);

        mSelectImage.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                Intent intent1 = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
                startActivityForResult(intent1, CAMERA_REQUEST_CODE);
                intent1.setType("image/*");

                /*
                Intent galleryIntent = new Intent(Intent.ACTION_GET_CONTENT);
                galleryIntent.setType("image/*");
                startActivityForResult(galleryIntent, GALLERY_REQUEST);
                */
            }
        });

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

    private void startPosting() {

        mProgress.setMessage("Posting to blog...");


        final String title_val = mPostTitle.getText().toString().trim();
        final String desc_val = mPostDesc.getText().toString().trim();
        if (!TextUtils.isEmpty(title_val) && !TextUtils.isEmpty(desc_val) && mImageUri != null) {

            mProgress.show();
            StorageReference filepath = mStorage.child("Blog_Images").child(mImageUri.getLastPathSegment());

            filepath.putFile(mImageUri).addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {
                @Override
                public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {
                    Uri downloadUrl = taskSnapshot.getDownloadUrl();

                    DatabaseReference newPost = mDatabase.push();
                    newPost.child("title").setValue(title_val);
                    newPost.child("desc").setValue(desc_val);
                    newPost.child("image").setValue(downloadUrl.toString());


                    mProgress.dismiss();
                    startActivity(new Intent(PostActivity.this, MainActivity.class));
                }
            });
        }
    }

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




        // if(requestCode == GALLERY_REQUEST && resultCode == RESULT_OK){
        if (requestCode == CAMERA_REQUEST_CODE && resultCode == RESULT_OK) {

      /*   mImageUri = data.getData();
            mSelectImage.setImageURI(mImageUri);

            CropImage.activity(mImageUri)
                    .setGuidelines(CropImageView.Guidelines.ON)

                    .start(this);

*/

            Bitmap mImageUri = (Bitmap) data.getExtras().get("data");
            mSelectImage.setImageBitmap(mImageUri);
       }


        if (requestCode == CropImage.CROP_IMAGE_ACTIVITY_REQUEST_CODE) {
            CropImage.ActivityResult result = CropImage.getActivityResult(data);
            if (resultCode == RESULT_OK) {
                Uri resultUri = result.getUri();
                mSelectImage.setImageURI(resultUri);
            } else if (resultCode == CropImage.CROP_IMAGE_ACTIVITY_RESULT_ERROR_CODE) {
                Exception error = result.getError();
            }
        }


    }



}
@DaminiMehra 您的答案是一个新函数，那么这个函数是要替换我的 startPosting() 函数吗？我在我的代码中做错了什么？ - Emilyy Lim
4个回答
4
我已找到解决问题的方法，我意识到可以使用data.getData()函数获取我的捕获数据，而不是使用Bitmap函数：
 mImageUri = data.getData();
            mSelectImage.setImageURI(mImageUri);

此外，我之前没有意识到我的“裁剪”功能无法正常工作，因为我缺少了：
mImageUri = resultUri;

我发现一个问题，如果我没有裁剪捕获的图像，Firebase将无法处理高分辨率（或存储大小？），并且加载速度非常慢/图像不会出现。这可以通过“裁剪”功能解决。
最终代码如下： 感谢大家的帮助。 
package simpleblog2.emily.example.com.simpleblog2;

import android.app.ProgressDialog;
import android.content.Intent;
import android.graphics.Bitmap;
import android.media.Image;
import android.net.Uri;

import android.provider.MediaStore;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.Toast;


import com.google.android.gms.tasks.OnSuccessListener;
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.UploadTask;


import com.theartofdev.edmodo.cropper.CropImage;
import com.theartofdev.edmodo.cropper.CropImageView;


public class PostActivity extends AppCompatActivity {

    private ImageButton mSelectImage;
    private EditText mPostTitle;
    private EditText mPostDesc;
    private Button mSubmitBtn;
    private ProgressDialog mProgress;
    private DatabaseReference mDatabase;

    private Uri mImageUri = null;

    private static final  int GALLERY_REQUEST =1;

    private static final int CAMERA_REQUEST_CODE=1;

    private StorageReference mStorage;

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

        mStorage = FirebaseStorage.getInstance().getReference();
        mDatabase = FirebaseDatabase.getInstance().getReference().child("Blog");

        mSelectImage = (ImageButton) findViewById(R.id.imageSelect);
        mPostTitle = (EditText)  findViewById(R.id.titleField);
        mPostDesc = (EditText) findViewById(R.id.descField);
        mSubmitBtn = (Button) findViewById(R.id.submitBtn);

        mProgress = new ProgressDialog(this);

        mSelectImage.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);

                if (intent.resolveActivity(getPackageManager()) != null) {
                    startActivityForResult(intent, CAMERA_REQUEST_CODE);
                }
                //startActivityForResult(intent,CAMERA_REQUEST_CODE);


/*
                Intent galleryIntent = new Intent(Intent.ACTION_GET_CONTENT);
                galleryIntent.setType("image/*");
                startActivityForResult(galleryIntent, GALLERY_REQUEST);

                */

            }
        });

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



    private void startPosting(){

        mProgress.setMessage("Posting to blog...");


        final String title_val = mPostTitle.getText().toString().trim();
        final String desc_val = mPostDesc.getText().toString().trim();
        if(!TextUtils.isEmpty(title_val)&&!TextUtils.isEmpty(desc_val) && mImageUri != null){

            mProgress.show();
            StorageReference filepath = mStorage.child("Blog_Images").child(mImageUri.getLastPathSegment());

            filepath.putFile(mImageUri).addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {
                @Override
                public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {
                    Uri downloadUrl =taskSnapshot.getDownloadUrl();

                    DatabaseReference newPost = mDatabase.push();
                    newPost.child("title").setValue(title_val);
                    newPost.child("desc").setValue(desc_val);
                    newPost.child("image").setValue(downloadUrl.toString());


                    mProgress.dismiss();
                    startActivity(new Intent(PostActivity.this,MainActivity.class));
                }
            });
        }
    }


    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
      // if(requestCode == GALLERY_REQUEST && resultCode == RESULT_OK){
       if(requestCode == CAMERA_REQUEST_CODE && resultCode == RESULT_OK){




        mImageUri = data.getData();
            mSelectImage.setImageURI(mImageUri);

            CropImage.activity(mImageUri)
                    .setGuidelines(CropImageView.Guidelines.ON)
                    .setAspectRatio(1,1)
                    .start(this);




        /* Bitmap mImageUri1 = (Bitmap) data.getExtras().get("data");
         mSelectImage.setImageBitmap(mImageUri1);

          Toast.makeText(this, "Image saved to:\n" +
                  data.getExtras().get("data"), Toast.LENGTH_LONG).show();


*/



        }

        if (requestCode == CropImage.CROP_IMAGE_ACTIVITY_REQUEST_CODE) {
            CropImage.ActivityResult result = CropImage.getActivityResult(data);
            if (resultCode == RESULT_OK) {
                Uri resultUri = result.getUri();

                mSelectImage.setImageURI(resultUri);
                mImageUri = resultUri;

            } else if (resultCode == CropImage.CROP_IMAGE_ACTIVITY_RESULT_ERROR_CODE) {
                Exception error = result.getError();
            }
        }


    }




}
我在 getdownloadurl() 中遇到了错误，该如何解决？ - Mridul Agarwal
0

   if (requestCode == CAMERA_REQUEST_CODE && resultCode == RESULT_OK) {

      /*   mImageUri = data.getData();
            mSelectImage.setImageURI(mImageUri);

            CropImage.activity(mImageUri)
                    .setGuidelines(CropImageView.Guidelines.ON)

                    .start(this);

*/

            Bitmap mImageUri = (Bitmap) data.getExtras().get("data");
            mSelectImage.setImageBitmap(mImageUri);
       }

你的URI可能是null。我猜这就是问题所在。 除非你在其他地方做了这件事？

图片可能会被加载，因为requestCode = CAMERA_REQUEST_CODE，但不是CropImage.CROP_IMAGE_ACTIVITY_RESULT_ERROR_CODE。

我将在下面发布一段代码，用于执行您要求的操作，但首先需要了解一些事情。 从Android 7版本开始，使用Uri.parseFromFile（file）会返回错误，因为Google希望限制您的访问权限。从现在开始，如果您想获取文件URI，则应使用{{link1：FileProvider}}。

  1. 在清单文件中声明权限和FileProvider：

       
//File provider declaration in manifest.
        <provider
            android:name="android.support.v4.content.FileProvider"
            android:authorities="com.hadas.yotam.manchworkers.provider"
            android:exported="false"
            android:grantUriPermissions="true">
            <meta-data
                android:name="android.support.FILE_PROVIDER_PATHS"
                android:resource="@xml/provider_paths"/>
        </provider>

//in new xml file define the location you need permmision to, the code below give you permmision for any external file.
<paths xmlns:android="http://schemas.android.com/apk/res/android">
    <external-path name="external_files" path="."/>
</paths>

所以现在当您上传时，如果onActivityResult成功，请使用全局Uri变量，以下是代码：

if(Build.VERSION.SDK_INT>=24) {
                            String file = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES)+"/" + Calendar.getInstance().getTimeInMillis() + ".jpg";
                            File file1 = new File(file);
                            photoURI = FileProvider.getUriForFile(this, getApplicationContext().getPackageName() + ".provider", file1);
                            intent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI);
                        }

然后在你的onActivityResult中，检查你的photoURI是否为null，如果是true（即为null），则使用photoURI = data.getData();

//if phone android version greater or equal to Marshmelo                    

if(Build.VERSION.SDK_INT>Build.VERSION_CODES.M){

//check if have permmission to write to external + permmision to camera

                    if(ContextCompat.checkSelfPermission(getApplicationContext(), Manifest.permission.WRITE_EXTERNAL_STORAGE)== PackageManager.PERMISSION_GRANTED &&
                            ContextCompat.checkSelfPermission(getApplicationContext(), Manifest.permission.CAMERA)== PackageManager.PERMISSION_GRANTED){

//if its have permission then new intent to capture image

                        intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);

//if android version >= 24 (Android Nugget)

                        if(Build.VERSION.SDK_INT>=24) {

//create new String to pictures directory and set the file name to current_time.jpg
                            String file = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES)+"/" + Calendar.getInstance().getTimeInMillis() + ".jpg";
                            File file1 = new File(file);

//set GLOBAL variable Uri from the file using FileProvider

                            photoURI = FileProvider.getUriForFile(this, getApplicationContext().getPackageName() + ".provider", file1);

//add the file location the intent (the picture will be save to this file)

                            intent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI);
                        }
                            tagIntent = CAPTURE_RESAULT;
//else - dont have permission, request for permission
                    }else{
                        requestPermissions(new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE,Manifest.permission.CAMERA},CAPTURE_RESAULT);
                    }
else - 
                }else{
// same thing only without FileProvider (FileProvider only required since Nugget)

                        intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
                        String file = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES)+"/" + Calendar.getInstance().getTimeInMillis() + ".jpg";
                        File file1 = new File(file);
                        photoURI = Uri.fromFile(file1);
                        intent.putExtra(MediaStore.EXTRA_OUTPUT,photoURI);
                    tagIntent = CAPTURE_RESAULT;
                }

//if phone can handle the intent, start the intent for resault.

                if(intent.resolveActivity(getPackageManager())!=null) {
            startActivityForResult(intent,tagIntent);
                }

是的，我将其设置为私有Uri mImageUri = null; 是否是我的错误原因？如果是，我应该改成什么？ - Emilyy Lim
我做过类似于你试图实现的事情，等我回家后会上传相关代码的部分。 - yotam hadas
通常情况下，您需要获取文件路径，但从数据中获取URL可能会返回null（取决于Android版本）。如果您使用6或以下版本，则可以使用：mImageUri = data.getData(); 如果您想确保获得Uri，我建议检查手机是否运行Android 6或更高版本，如果是，则在捕获意图中添加文件位置的额外内容并从文件中获取URI。 - yotam hadas
我编辑了我的回答，希望能对你有所帮助。问题在于，在SDK 24以下的手机上，你只需要在onActivityResult中使用mImageUri = data.getData()，但在24以上的版本中，它只返回缩略图而不是整个文件（不确定为什么），因此你需要告诉系统在哪里保存捕获的图片，然后使用文件+FileProvider来获取URI。 - yotam hadas
我不明白在哪里放置externalpath这部分代码，应该把它放在哪里？我查看了https://developer.android.com/training/camera/photobasics.html，但仍然无法理解应该将代码放在哪里。 - Emilyy Lim
0

之前是 if auth != null，但我把它改成了 if true，这样 if 语句就会始终为真。

  private void uploadFile() {
    //if there is a file to upload
    if (filePath != null) {
        //displaying a progress dialog while upload is going on
        final ProgressDialog progressDialog = new ProgressDialog(this);
        progressDialog.setTitle("Uploading");
        progressDialog.show();

        StorageReference riversRef = storageReference.child("Blog_Images.jpg");
        riversRef.putFile(filePath)
                .addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {
                    @Override
                    public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {
                        //if the upload is successfull
                        //and displaying a success toast
                        Toast.makeText(getApplicationContext(), "File Uploaded ", Toast.LENGTH_LONG).show();
                    }
                })
                .addOnFailureListener(new OnFailureListener() {
                    @Override
                    public void onFailure(@NonNull Exception exception) {
                        //if the upload is not successfull
                        //hiding the progress dialog
                        progressDialog.dismiss();

                        //and displaying error message
                        Toast.makeText(getApplicationContext(), exception.getMessage(), Toast.LENGTH_LONG).show();
                    }
                })
                .addOnProgressListener(new OnProgressListener<UploadTask.TaskSnapshot>() {
                    @Override
                    public void onProgress(UploadTask.TaskSnapshot taskSnapshot) {
                        //calculating progress percentage
                        double progress = (100.0 * taskSnapshot.getBytesTransferred()) / taskSnapshot.getTotalByteCount();

                        //displaying percentage in progress dialog
                        progressDialog.setMessage("Uploaded " + ((int) progress) + "%...");
                    }
                });
    }
    //if there is not any file
    else {
        //you can display an error toast
    }
}
0
你的类字段 mImageUri 从未被初始化。你将接收到的位图放在本地字段中，该字段与类字段同名。
Bitmap mImageUri = (Bitmap) data.getExtras().get("data");
mSelectImage.setImageBitmap(mImageUri);

因此，该条件从未为真。

if (!TextUtils.isEmpty(title_val) && !TextUtils.isEmpty(desc_val) && mImageUri != null)
我使用私有的Uri mImageUri = null进行初始化，但仍然出现相同的错误。 - Emilyy Lim
没错，你用 null 进行了初始化，然后检查它是否为 null。你从未覆盖 null 值，所以条件 mImageUri !=null 永远不会成立。 - mol
网页内容由stack overflow 提供, 点击上面的
可以查看英文原文，
原文链接