上传到 Firebase 的图片都是黑色的。如何摆脱它？答案

【问题标题】：Uploaded images to Firebase are all black. How to get rid of it?上传到 Firebase 的图片都是黑色的。如何摆脱它？
【发布时间】：2017-11-06 11:28:22
【问题描述】：

用户从相机或图库中选择图像，因此现在图像位于 Imageview 中以向用户显示图片。现在用户上传到服务器，但是我上传的每张图片都是黑色的。为什么会这样？这是代码：

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

        final StorageReference storageRef = FirebaseStorage.getInstance().getReferenceFromUrl("gs://lalala-14247.appspot.com");

        mImageview.setDrawingCacheEnabled(true);
        mImageview.buildDrawingCache();
        Bitmap bitmap = mImageview .getDrawingCache();

        ByteArrayOutputStream baas = new ByteArrayOutputStream();
        bitmap.compress(Bitmap.CompressFormat.JPEG, 100, baas);

        byte[] data = baas.toByteArray();
        String timeStamp = new SimpleDateFormat("yyyyMMddHHmmss").format(new Date());

        UploadTask uploadTask = storageRef.child("Photo").child(timeStamp).putBytes(data);

        uploadTask.addOnFailureListener(new OnFailureListener() {
            @Override
            public void onFailure(@NonNull Exception exception) {
                Toast.makeText(MainActivity.this, "Picture upload failed", Toast.LENGTH_LONG).show();
            }
        }).addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {
            @Override
            public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {
                Toast.makeText(MainActivity.this, "Upload done", Toast.LENGTH_LONG).show();

            }
        });

    }

});

我的依赖：

compile 'com.android.support:appcompat-v7:25.3.1'
compile 'com.android.support.constraint:constraint-layout:1.0.2'
compile 'com.squareup.picasso:picasso:2.5.2'
compile 'com.google.firebase:firebase-storage:10.0.1'
compile 'com.google.firebase:firebase-auth:10.0.1'
compile 'com.google.firebase:firebase-database:10.0.1'
testCompile 'junit:junit:4.12'

【问题讨论】：

嗨@Jessef，考虑使用putStream() 或putFile()，也可以使用更少的内存。
嘿，谢谢 :) 但是我在哪里添加这个？

标签： android image firebase file-upload firebase-storage

【解决方案1】：

试试这个，

Uri file = Uri.fromFile(new File("your_image_path"));
StorageReference riversRef = storageRef.child("images/"+file.getLastPathSegment());
uploadTask = riversRef.putFile(file);

// Register observers to listen for when the download is done or if it fails
uploadTask.addOnFailureListener(new OnFailureListener() {
    @Override
    public void onFailure(@NonNull Exception exception) {
        // Handle unsuccessful uploads
    }
}).addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {
    @Override
    public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {
        // taskSnapshot.getMetadata() contains file metadata such as size, content-type, and download URL.
        Uri downloadUrl = taskSnapshot.getDownloadUrl();
    }
});

【讨论】：

【解决方案2】：

final int backgroundPreviousColor = view.getDrawingCacheBackgroundColor();
view.setDrawingCacheEnabled(true);
view.setDrawingCacheBackgroundColor(0xfffafafa);
final Bitmap bitmap = view.getDrawingCache();
view.setDrawingCacheBackgroundColor(backgroundPreviousColor);
bitmap.compress(Bitmap.CompressFormat.JPEG, 80, stream);
view.setDrawingCacheEnabled(cachePreviousState);

这对我有帮助

【讨论】：