[英]Create byte array in JavaScript
有沒有一種方法可以從JavaScript(或Typescript)文件中創建字節數組,該文件將發送到C#WebApi服務,並由C#字節數組方法參數使用? 如果是這樣,您可以提供一個JavaScript示例嗎?
我應該提到,這是一個將發布到該服務的Angular 4+應用程序。
我需要將Word文檔,PDF和圖像上載到C#服務,這是當前構建C#服務的方式。 期望要上傳的文件的字節數組。
這是C#服務的請求對象:
[DataContract]
public class SaveAttachmentRequest : BaseRequest
{
[RestUrlParameter(Mode = UrlParameterMode.Inline)]
[DataMember(IsRequired = true)] public AttachmentLookupInformation LookupInformation { get; set; } = new AttachmentLookupInformation();
[DataMember(IsRequired = true)] public byte[] Attachment { get; set; } = null;
}
這是AttachmentLookupInformation類:
[DataContract]
public class AttachmentLookupInformation
{
[DataMember(IsRequired = true)] public Guid Id { get; set; } = Guid.Empty;
[DataMember(IsRequired = true)] public Guid LinkedToId { get; set; } = Guid.Empty;
///<summary>Not including the path- just the file name and extension.</summary>
[DataMember(IsRequired = true)] public string FileName { get; set; } = string.Empty;
[DataMember(IsRequired = true)] public int FileSizeInBytes { get; set; } = 0;
///<summary>MIME type.</summary>
[DataMember(IsRequired = true)] public string ContentType { get; set; } = string.Empty;
[DataMember(IsRequired = true)] public AttachmentCategories AttachmentCategory { get; set; } = AttachmentCategories.Unknown;
[DataMember(IsRequired = true)] public string DownloadUrl { get; set; } = string.Empty;
[DataMember(IsRequired = true)] public string CreatedBy { get; set; } = string.Empty;
[DataMember(IsRequired = true)] public DateTimeOffset CreatedTimestamp { get; set; } = DateTimeOffset.MinValue;
}
這樣我就可以將文件和其他數據上傳到服務。
編輯:包括我使用的失敗的Angular代碼:
const lookupInfo = new AttachmentLookupInformation();
lookupInfo.Id = Helpers.emptyGuid;
lookupInfo.LinkedToId = this.contractId;
lookupInfo.AttachmentCategory = 10;
const request = new SaveAttachmentRequest();
const reader = new FileReader();
reader.onload = function() {
const buffer = reader.result;
let binary = '';
const bytes = new Uint8Array(buffer);
const length = bytes.byteLength;
for (let i = 0; i < length; i++) {
binary += String.fromCharCode(bytes[i]);
}
request.Attachment = binary;
lookupInfo.ContentType = files[0].type;
lookupInfo.FileName = files[0].name;
lookupInfo.FileSizeInBytes = length;
};
reader.readAsArrayBuffer(files[0]);
reader.onloadend = function() {
request.LookupInformation = lookupInfo;
console.log('request: ', request);
that.contractsService
.save(request, 'attachment/saveattachment')
.subscribe(res => {
if (res.Success) {
console.log('upload response: ', res);
}
});
};
好吧,你有:
that.contractsService
.save(request, 'attachment/saveattachment')
但是您要顯示的類是SaveAttachmentRequest
,其中包含public byte[] Attachment
。 我認為,您的問題中沒有一個函數稱為saveattachment
,該類稱為attachment
,這是應該處理的數據傳輸到byte []的過程,除非您以某種方式直接將其設置為參數。 假設您具有此類attachment
類,則應該在其中有一個名為saveattachment
的入口點可以完成所有工作。 但是要說這是失敗的,因為您正在傳遞JS模型並將其直接映射到.NET。 因此,創建一個可以接受您的二進制字符串的字符串參數,然后將其保存到您的byte[]
。
[DataMember(IsRequired = true)] public string strAttachment { get; set; } = null;
在你的JS里
request.Attachment = binary;
變成
request.strAttachment = binary;
然后,您需要:
public class attachment : ApiController
{
[System.Web.Http.HttpPost]
public JsonResult saveattachment(SaveAttachmentRequest sar, AttachmentLookupInformation ali)
{
//string bits = "000011110000001000";
string bits = sar.strAttachment;
int numOfBytes = (int)Math.Ceiling(bits.Length / 8m);
byte[] bytes = new byte[numOfBytes];
int chunkSize = 8;
for (int i = 1; i <= numOfBytes; i++)
{
int startIndex = bits.Length - 8 * i;
if (startIndex < 0)
{
chunkSize = 8 + startIndex;
startIndex = 0;
}
bytes[numOfBytes - i] = Convert.ToByte(bits.Substring(startIndex, chunkSize), 2);
}
sar.attachment = bytes;
// ... do your other stuff for saving your model objects to the DB
// using Entity Framework's data context, etc.
}
}
那只是將二進制字符串轉換為byte []的一種方法。 這里還有很多其他方式。
或者,您是否嘗試過僅將其作為字符串發送,因此:
[DataMember(IsRequired = true)] public byte[] Attachment { get; set; } = null;
變成這個:
[DataMember(IsRequired = true)] public string Attachment { get; set; } = null;
首先?
在文件類型輸入更改事件中,您可以獲得字節數組。 這應該對您有幫助。
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