Writing a byte array to an Excel file
I've been given the task of writing automated tests that check our own API. Part of this process involves testing an end point that generates an Excel template that the recipient is then supposed to fill back out and submit back to us.
From the looks of things this template gets sent back to the user from within the browser using a FileContentResult object that also specifies the content type (application/vnd.ms-excel.sheet.macroEnabled.12; the intended file format is .xlsm).
The problem I have is this: whilst getting the file in terms of a byte array works without issue with regards to the call to the end point is concerned I have yet to successfully take that byte array returned and use it for anything useful. Creating an excel file from that seems to be problematic. Just using File.WriteAllBytes() doesn't seem to work for example nor does using a BinaryWriter.
Does anybody have any idea how to achieve this from within C# code that isn't running as part of a website?
c# excel
edited Nov 14 '18 at 16:18
Uwe Keim
27.5k32130212
asked Nov 14 '18 at 16:17
PatrickAPatrickA
146117
add a comment |
I've been given the task of writing automated tests that check our own API. Part of this process involves testing an end point that generates an Excel template that the recipient is then supposed to fill back out and submit back to us.
From the looks of things this template gets sent back to the user from within the browser using a FileContentResult object that also specifies the content type (application/vnd.ms-excel.sheet.macroEnabled.12; the intended file format is .xlsm).
The problem I have is this: whilst getting the file in terms of a byte array works without issue with regards to the call to the end point is concerned I have yet to successfully take that byte array returned and use it for anything useful. Creating an excel file from that seems to be problematic. Just using File.WriteAllBytes() doesn't seem to work for example nor does using a BinaryWriter.
Does anybody have any idea how to achieve this from within C# code that isn't running as part of a website?
c# excel
edited Nov 14 '18 at 16:18
Uwe Keim
27.5k32130212
asked Nov 14 '18 at 16:17
PatrickAPatrickA
146117
1
If the byte array is supposed to be an excel file then File.WriteAllBytes() would be the way to create it on disk, you say it doesn't work, what happens? - The first thing to do would be to open the created file in a text editor and see if contains something unexpected - i.e plaintext.
– Alex K.
Nov 14 '18 at 16:30
1
I believe I've found the answer: it was a fundamental misunderstanding on my part. I thought what I had was a string representation of a byte array. It turns out it was base64 encoded and that also needed to be dealt with. As soon as I added the call to Convert.FromBase64String() instead of just straight up taking the value and converting it to a byte array it worked fine.
– PatrickA
Nov 14 '18 at 16:47
add a comment |
I've been given the task of writing automated tests that check our own API. Part of this process involves testing an end point that generates an Excel template that the recipient is then supposed to fill back out and submit back to us.
From the looks of things this template gets sent back to the user from within the browser using a FileContentResult object that also specifies the content type (application/vnd.ms-excel.sheet.macroEnabled.12; the intended file format is .xlsm).
The problem I have is this: whilst getting the file in terms of a byte array works without issue with regards to the call to the end point is concerned I have yet to successfully take that byte array returned and use it for anything useful. Creating an excel file from that seems to be problematic. Just using File.WriteAllBytes() doesn't seem to work for example nor does using a BinaryWriter.
Does anybody have any idea how to achieve this from within C# code that isn't running as part of a website?
c# excel
edited Nov 14 '18 at 16:18
Uwe Keim
27.5k32130212
asked Nov 14 '18 at 16:17
PatrickAPatrickA
146117
I've been given the task of writing automated tests that check our own API. Part of this process involves testing an end point that generates an Excel template that the recipient is then supposed to fill back out and submit back to us.
From the looks of things this template gets sent back to the user from within the browser using a FileContentResult object that also specifies the content type (application/vnd.ms-excel.sheet.macroEnabled.12; the intended file format is .xlsm).
The problem I have is this: whilst getting the file in terms of a byte array works without issue with regards to the call to the end point is concerned I have yet to successfully take that byte array returned and use it for anything useful. Creating an excel file from that seems to be problematic. Just using File.WriteAllBytes() doesn't seem to work for example nor does using a BinaryWriter.
Does anybody have any idea how to achieve this from within C# code that isn't running as part of a website?
c# excel
c# excel
edited Nov 14 '18 at 16:18
Uwe Keim
27.5k32130212
asked Nov 14 '18 at 16:17
PatrickAPatrickA
146117
edited Nov 14 '18 at 16:18
Uwe Keim
27.5k32130212
asked Nov 14 '18 at 16:17
PatrickAPatrickA
146117
edited Nov 14 '18 at 16:18
Uwe Keim
27.5k32130212
edited Nov 14 '18 at 16:18
Uwe Keim
27.5k32130212
edited Nov 14 '18 at 16:18
Uwe Keim
27.5k32130212
27.5k32130212
asked Nov 14 '18 at 16:17
PatrickAPatrickA
146117
asked Nov 14 '18 at 16:17
PatrickAPatrickA
146117
asked Nov 14 '18 at 16:17
PatrickAPatrickA
146117
146117
1
If the byte array is supposed to be an excel file then File.WriteAllBytes() would be the way to create it on disk, you say it doesn't work, what happens? - The first thing to do would be to open the created file in a text editor and see if contains something unexpected - i.e plaintext.
– Alex K.
Nov 14 '18 at 16:30
1
I believe I've found the answer: it was a fundamental misunderstanding on my part. I thought what I had was a string representation of a byte array. It turns out it was base64 encoded and that also needed to be dealt with. As soon as I added the call to Convert.FromBase64String() instead of just straight up taking the value and converting it to a byte array it worked fine.
– PatrickA
Nov 14 '18 at 16:47
add a comment |
1
If the byte array is supposed to be an excel file then File.WriteAllBytes() would be the way to create it on disk, you say it doesn't work, what happens? - The first thing to do would be to open the created file in a text editor and see if contains something unexpected - i.e plaintext.
– Alex K.
Nov 14 '18 at 16:30
1
I believe I've found the answer: it was a fundamental misunderstanding on my part. I thought what I had was a string representation of a byte array. It turns out it was base64 encoded and that also needed to be dealt with. As soon as I added the call to Convert.FromBase64String() instead of just straight up taking the value and converting it to a byte array it worked fine.
– PatrickA
Nov 14 '18 at 16:47
1
1
If the byte array is supposed to be an excel file then File.WriteAllBytes() would be the way to create it on disk, you say it doesn't work, what happens? - The first thing to do would be to open the created file in a text editor and see if contains something unexpected - i.e plaintext.
– Alex K.
Nov 14 '18 at 16:30
If the byte array is supposed to be an excel file then File.WriteAllBytes() would be the way to create it on disk, you say it doesn't work, what happens? - The first thing to do would be to open the created file in a text editor and see if contains something unexpected - i.e plaintext.
– Alex K.
Nov 14 '18 at 16:30
1
1
I believe I've found the answer: it was a fundamental misunderstanding on my part. I thought what I had was a string representation of a byte array. It turns out it was base64 encoded and that also needed to be dealt with. As soon as I added the call to Convert.FromBase64String() instead of just straight up taking the value and converting it to a byte array it worked fine.
– PatrickA
Nov 14 '18 at 16:47
I believe I've found the answer: it was a fundamental misunderstanding on my part. I thought what I had was a string representation of a byte array. It turns out it was base64 encoded and that also needed to be dealt with. As soon as I added the call to Convert.FromBase64String() instead of just straight up taking the value and converting it to a byte array it worked fine.
– PatrickA
Nov 14 '18 at 16:47
add a comment |
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1
If the byte array is supposed to be an excel file then File.WriteAllBytes() would be the way to create it on disk, you say it doesn't work, what happens? - The first thing to do would be to open the created file in a text editor and see if contains something unexpected - i.e plaintext.
– Alex K.
Nov 14 '18 at 16:30
1
I believe I've found the answer: it was a fundamental misunderstanding on my part. I thought what I had was a string representation of a byte array. It turns out it was base64 encoded and that also needed to be dealt with. As soon as I added the call to Convert.FromBase64String() instead of just straight up taking the value and converting it to a byte array it worked fine.
– PatrickA
Nov 14 '18 at 16:47