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27
4
1、附属文件对象定义 。
一般情况下，系统里面的文件都会附属一个对象存在，例如用户的头像文件，会附属用户对象存在。邮件中的文件会附属邮件存在。所以在系统里面，我们会创建一个附属文件对象，命名为AttachedFileEntity。其定义如下所示.
///
<summary>
///
附属文件实体对象
///
</summary>
public
class
AttachedFileEntity
{
///
<summary>
///
实体对象GUID
///
</summary>
public
string
GUID {
get
;
set
; } =
""
;
///
<summary>
///
所属对象的GUID
///
</summary>
public
string
EntityGUID {
get
;
set
; } =
""
;
///
<summary>
///
名称
///
</summary>
public
string
Name {
get
;
set
; } =
""
;
///
<summary>
///
关键字
///
</summary>
public
string
KeyWord {
get
;
set
; } =
""
;
///
<summary>
///
文件大小
///
</summary>
public
int
FileSize {
get
;
set
; } =
0
;
///
<summary>
///
服务器存储路径
///
</summary>
public
string
ServerPath {
get
;
set
; } =
""
;
///
<summary>
///
描述信息
///
</summary>
public
string
Description {
get
;
set
; } =
""
;
}
EntityGUID属性的作用是，定义该文件属于哪个实体对象，例如某个用户的头像文件，该属性就是这个用户对象的GUID值.
KeyWord属性用来标识文件。例如UserEntity有两个文件，头像和一个自我介绍的视频文件。这两个文件的EntityGUID都是UserEntity的GUID，那么就可以通过KeyWord来区分两个文件是做什么用的.
2、小文件上传服务 。
如果一个文件比较小，例如3M以内，那么我们就可以一次性把文件上传上来，上传的时候，要把AttachedFileEntity对象传进来，并添加到数据库中.
代码如下所示.
///
<summary>
///
上传文件
///
</summary>
///
<param name="pEntity"></param>
///
<returns></returns>
[HttpPost]
[Route(
"
UploadFile
"
)]
public
IActionResult UploadFile()
{
//
获取客户端传来的数据
var
myEntityJosnString = Request.Form[
"
pEntity
"
].ToString();
var
myEntity = JsonSerializer.Deserialize<AttachedFileEntity>
(myEntityJosnString);
var
myFile = Request.Form.Files[
0
];
//
设置新的文件路径
string
myFileEx =
Path.GetExtension(myFile.FileName);
string
myServerFilePath = DateTime.Now.ToString(
"
yyyy_MM_dd
"
) +
"
\\
"
+ Guid.NewGuid().ToString() +
myFileEx;
myEntity
!.ServerPath =
myServerFilePath;
//
创建目录
string
myFullServerPath = AppDomain.CurrentDomain.BaseDirectory +
"
\\Files\\
"
+
myServerFilePath;
string
myFullFolder = Path.GetDirectoryName(myFullServerPath)!
;
if
(Directory.Exists(myFullFolder) ==
false
)
{
Directory.CreateDirectory(myFullFolder);
}
Stream
? myStream =
null
;
FileStream
? myFileStream =
null
;
BinaryWriter
? myBinaryWriter =
null
;
try
{
myStream
=
myFile.OpenReadStream();
byte
[] myBytes =
new
byte
[myStream.Length];
myStream.Read(myBytes,
0
, myBytes.Length);
myStream.Seek(
0
, SeekOrigin.Begin);
myFileStream
=
new
FileStream(myFullServerPath, FileMode.Create);
myBinaryWriter
=
new
BinaryWriter(myFileStream);
myBinaryWriter.Write(myBytes);
}
finally
{
myBinaryWriter
?
.Close();
myFileStream
?
.Close();
myStream
?
.Close();
}
//
把附属文件对象保存到数据库中
//
代码略
return
this
.Ok(myEntity);
}
因为我们要传入两个复杂的对象AttachedFileEntity和File，所以就不能用参数接了，就需要用代码从Request里面读取。文件其本质就是二进制数据，我们获取这个二进制之后，把数据保存成文件就可以了。然后把pEntity写入到数据库中.
3、前端调用 。
先用桌面端测试，界面是用C#写的WPF桌面软件，入下图所示.
调用代码入下所示.
var
myFilePath =
this
.UI_SmallFile_TextBox.Text.Trim();
if
(myFilePath.Length ==
0
)
{
MessageBox.Show(
"
请选择一个文件。
"
);
return
;
}
if
(File.Exists(myFilePath) ==
false
)
{
MessageBox.Show(
"
文件不存在，请重新选择。
"
);
return
;
}
//
定义AttachedFileEntity
var
myAttachedFileEntity =
new
AttachedFileEntity()
{
GUID
=
Guid.NewGuid().ToString(),
Name
=
"
用户头像
"
,
KeyWord
=
"
UserProfilePhoto
"
,
Description
=
""
,
EntityGUID
=
"
AAAA
"
};
//
定义请求内容
var
myFileStream =
new
FileStream(myFilePath, FileMode.Open);
myAttachedFileEntity.FileSize
= (
int
)myFileStream.Length;
var
myFileName =
Path.GetFileName(myFilePath);
var
myFileStreamContent =
new
StreamContent(myFileStream);
var
myMultipartFormDataContent =
new
MultipartFormDataContent
{
{ JsonContent.Create(myAttachedFileEntity),
"
pEntity
"
},
{ myFileStreamContent,
"
pFormFile
"
, myFileName }
};
//
请求服务
var
myHttpClientEx =
new
HttpClientEx(
new
HttpClient())
{
Url
=
"
http://localhost:5000/api/AttachedFile/UploadFile
"
,
HttpContent
=
myMultipartFormDataContent
};
await
myHttpClientEx.PostAsync();
myFileStream.Close();
//
解析结果
if
(myHttpClientEx.IsSuccess ==
false
)
{
MessageBox.Show((
"
上传文件失败,
"
+
myHttpClientEx.ResponseContenString));
return
;
}
var
myEntity = myHttpClientEx.GetResponseObject<AttachedFileEntity>
();
var
myEntityJosnString =
JsonSerializer.Serialize(myEntity);
MessageBox.Show(myEntityJosnString);
HttpClientEx是对.Net定义的HttpClient一些功能的扩展，这样用起来会比较方便，代码定义如下.
///
<summary>
///
HttpClient的自定义扩展类
///
</summary>
public
class
HttpClientEx
{
///
<summary>
///
HttpClient的自定义扩展类
///
</summary>
///
<param name="pHttpClient"></param>
public
HttpClientEx(HttpClient?
pHttpClient)
{
this
.HttpClient =
pHttpClient;
this
.ParameterDictionary =
new
Dictionary<
string
,
string
>
();
}
///
<summary>
///
HttpClient对象
///
</summary>
public
HttpClient? HttpClient {
get
;
private
set
; }
///
<summary>
///
服务地址
///
</summary>
public
string
Url {
get
;
set
; } =
""
;
///
<summary>
///
参数字典
///
</summary>
public
Dictionary<
string
,
string
> ParameterDictionary {
get
;
private
set
; }
///
<summary>
///
请求内容
///
</summary>
public
HttpContent? HttpContent {
get
;
set
; }
///
<summary>
///
请求返回的消息
///
</summary>
public
HttpResponseMessage? ResponseMessage {
get
;
private
set
; }
///
<summary>
///
是否执行成功
///
</summary>
public
bool
IsSuccess {
get
;
private
set
; }
///
<summary>
///
返回的内容字符串
///
</summary>
public
string
ResponseContenString {
get
;
private
set
; } =
""
;
///
<summary>
///
Get
///
</summary>
///
<returns></returns>
public
async
Task GetAsync()
{
var
myUrlWithParameters =
this
.GetUrlWithParameters();
this
.ResponseMessage =
await
this
.HttpClient!
.GetAsync(myUrlWithParameters);
this
.IsSuccess =
this
.ResponseMessage.IsSuccessStatusCode;
this
.ResponseContenString =
await
this
.ResponseMessage.Content.ReadAsStringAsync();
}
///
<summary>
///
Get
///
</summary>
///
<returns></returns>
public
async
Task PostAsync()
{
var
myUrlWithParameters =
this
.GetUrlWithParameters();
this
.ResponseMessage =
await
this
.HttpClient!.PostAsync(myUrlWithParameters,
this
.HttpContent);
this
.IsSuccess =
this
.ResponseMessage.IsSuccessStatusCode;
this
.ResponseContenString =
await
this
.ResponseMessage.Content.ReadAsStringAsync();
}
///
<summary>
///
得到返回的对象
///
</summary>
///
<typeparam name="T"></typeparam>
///
<returns></returns>
public
T? GetResponseObject<T>
()
{
if
(
this
.ResponseContenString ==
""
)
{
return
default
;
}
var
myJsonSerializerOptions =
new
JsonSerializerOptions()
{
PropertyNameCaseInsensitive
=
true
};
return
JsonSerializer.Deserialize<T>(
this
.ResponseContenString, myJsonSerializerOptions);
}
///
<summary>
///
得到带参数的Url
///
</summary>
///
<returns></returns>
private
string
GetUrlWithParameters()
{
if
(
this
.ParameterDictionary ==
null
)
{
return
this
.Url;
}
if
(
this
.ParameterDictionary.Count ==
0
)
{
return
this
.Url;
}
var
myParameterList =
new
List<
string
>
();
foreach
(
var
myItem
in
this
.ParameterDictionary)
{
myParameterList.Add(myItem.Key
+
"
=
"
+
myItem.Value);
}
return
this
.Url +
"
?
"
+
string
.Join(
"
&
"
, myParameterList);
}
}
如果客户端是Js，就需要自己组织服务需要的数据了。代码入下所示.
var
myFileReader =
new
FileReader();
var
myFileName = ""
;
myFileReader.onloadend
=
function
() {
var
myFileResult =
myFileReader.result;
var
myFileLength =
myFileResult.byteLength;
var
myFileEntity =
new
Object()
{
ServerPath:
""
};
Upload();
function
Upload() {
var
myByteArray = myFileResult.slice(0
, myFileLength);
var
myBlob =
new
Blob([myByteArray]);
var
myFile =
new
File([myBlob], myFileName);
var
myFormData =
new
FormData();
myFormData.append(
"file"
, myFile)
myFormData.append(
"pEntity"
, json.stringify(myFileEntity));
request.post(myUrl, {
data: myFormData
}).then(
function
(data) {
myFileEntity
=
json.parse(data);
alert(
"上传文件结束。"
);
alert(json.stringify(myFileEntity));
},
function
(err) {
alert(err);
return
;
});
}
}
myFileName
=
this
.files[0
].name;
myFileReader.readAsArrayBuffer(
this
.files[0]);
最后此篇关于.NetWebAPI005Controller上传小文件的文章就讲到这里了,如果你想了解更多关于.NetWebAPI005Controller上传小文件的内容请搜索CFSDN的文章或继续浏览相关文章，希望大家以后支持我的博客！ 。
27
4
0
我有以下正则表达式 /[a-zA-Z0-9_-]/ 当字符串只包含从 a 到z 大小写、数字、_ 和 -。 我的代码有什么问题？ 能否请您向我提供一个简短的解释和有关如何修复它的代码示例？ //var
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