Class: ClientRequest
Class: ClientRequest
Make HTTP/HTTPS requests.发出HTTP/HTTPS请求。
Process:进程：Main
This class is not exported from the 此类不是从'electron' module. 'electron'模块导出的。It is only available as a return value of other methods in the Electron API.它只能作为Electron API中其他方法的返回值使用。
ClientRequest implements the Writable Stream interface and is therefore an EventEmitter.实现了可写流接口，因此是一个EventEmitter。
new ClientRequest(options)
options properties such as protocol, host, hostname, port and path strictly follow the Node.js model as described in the URL module.options属性（如protocol、host、hostname、port和path）严格遵循URL模块中描述的Node.js模型。
For instance, we could have created the same request to 'github.com' as follows:例如，我们可以创建对“githubcom”的相同请求，如下所示：
const request = net.request({
method: 'GET',
protocol: 'https:',
hostname: 'github.com',
port: 443,
path: '/'
})
Instance Events实例事件
Event: 'response'
Returns:返回：
responseIncomingMessage -An object representing the HTTP response message.表示HTTP响应消息的对象。
Event: 'login'
Returns:返回：
authInfoObjectisProxybooleanschemestringhoststringportIntegerrealmstring
callbackFunctionusernamestring (optional)passwordstring (optional)
Emitted when an authenticating proxy is asking for user credentials.当身份验证代理请求用户凭据时发出。
The callback function is expected to be called back with user credentials:callback应使用用户凭据进行回调：
usernamestringpasswordstring
request.on('login', (authInfo, callback) => {
callback('username', 'password')
})
Providing empty credentials will cancel the request and report an authentication error on the response object:提供空凭据将取消请求并报告响应对象上的身份验证错误：
request.on('response', (response) => {
console.log(`STATUS: ${response.statusCode}`);
response.on('error', (error) => {
console.log(`ERROR: ${JSON.stringify(error)}`)
})
})
request.on('login', (authInfo, callback) => {
callback()
})
Event: 'finish'
Emitted just after the last chunk of the 在request's data has been written into the request object.request的最后一个数据块写入request对象之后立即发出。
Event: 'abort'
Emitted when the 当request is aborted. request中止时发出。The 如果abort event will not be fired if the request is already closed.request已关闭，则不会触发abort事件。
Event: 'error'
Returns:返回：
errorError -an error object providing some information about the failure.提供有关故障的一些信息的错误对象。
Emitted when the 当网络模块无法发出网络请求时发出。net module fails to issue a network request. Typically when the 通常，当request object emits an error event, a close event will subsequently follow and no response object will be provided.request对象发出error事件时，随后会发生close事件，并且不会提供响应对象。
Event: 'close'
Emitted as the last event in the HTTP request-response transaction. 作为HTTP请求-响应事务中的最后一个事件发出。The close event indicates that no more events will be emitted on either the request or response objects.close事件表示不再在request或response对象上发出任何事件。
Event: 'redirect'
Returns:返回：
statusCodeIntegermethodstringredirectUrlstringresponseHeadersRecord<string, string[]>
Emitted when the server returns a redirect response (e.g. 301 Moved Permanently). 当服务器返回重定向响应时发出（例如301 Moved Permanently）。Calling request.followRedirect will continue with the redirection. 调用request.followRedirect将继续重定向。If this event is handled, request.followRedirect must be called synchronously, otherwise the request will be cancelled.如果处理了此事件，则必须同步调用request.followRedirect，否则该请求将被取消。
Instance Properties实例属性
request.chunkedEncoding
A 一个boolean specifying whether the request will use HTTP chunked transfer encoding or not. boolean，指定请求是否将使用HTTP分块传输编码。Defaults to false. 默认为false。The property is readable and writable, however it can be set only before the first write operation as the HTTP headers are not yet put on the wire. 该属性是可读写的，但只能在第一次写入操作之前设置，因为HTTP标头尚未连接。Trying to set the 在第一次写入后尝试设置chunkedEncoding property after the first write will throw an error.chunkedEncoding属性将引发错误。
Using chunked encoding is strongly recommended if you need to send a large request body as data will be streamed in small chunks instead of being internally buffered inside Electron process memory.如果您需要发送一个大的请求体，强烈建议使用分块编码，因为数据将以小块的形式进行流式传输，而不是在Electron进程内存中进行内部缓冲。
Instance Methods实例方法
request.setHeader(name, value)
namestring -An extra HTTP header name.额外的HTTP标头名称。valuestring -An extra HTTP header value.额外的HTTP标头值。
Adds an extra HTTP header. 添加一个额外的HTTP标头。The header name will be issued as-is without lowercasing. 标头名称将按原样发布，不使用小写字母。It can be called only before first write. 它只能在第一次写入之前调用。Calling this method after the first write will throw an error. 在第一次写入之后调用此方法将引发错误。If the passed value is not a 如果传递的值不是string, its toString() method will be called to obtain the final value.string，则将调用其toString()方法以获得最终值。
Certain headers are restricted from being set by apps. 某些标头被应用程序限制设置。These headers are listed below. 下面列出了这些标题。More information on restricted headers can be found in Chromium's header utils.有关受限标头的更多信息，可以在Chromium的标头实用程序中找到。
Content-LengthHostTrailerorTeUpgradeCookie2Keep-AliveTransfer-Encoding
Additionally, setting the 此外，还不允许将Connection header to the value upgrade is also disallowed.Connection标头设置为值upgrade。
request.getHeader(name)
namestring -Specify an extra header name.指定一个额外的标头名称。
Returns返回string - The value of a previously set extra header name.先前设置的额外标头名称的值。
request.removeHeader(name)
namestring -Specify an extra header name.指定一个额外的标头名称。
Removes a previously set extra header name. 删除以前设置的额外标头名称。This method can be called only before first write. 此方法只能在第一次写入之前调用。Trying to call it after the first write will throw an error.在第一次写入后尝试调用它将引发错误。
request.write(chunk[, encoding][, callback])
chunk(string | Buffer) -A chunk of the request body's data.请求主体的数据块。If it is a string, it is converted into a Buffer using the specified encoding.如果它是一个字符串，则会使用指定的编码将其转换为Buffer。encodingstring (optional) -Used to convert string chunks into Buffer objects.用于将字符串块转换为Buffer对象。Defaults to 'utf-8'.默认为“utf-8”。callbackFunction (optional) -Called after the write operation ends.在写入操作结束后调用。
callback is essentially a dummy function introduced in the purpose of keeping similarity with the Node.js API. 本质上是为了与Node.js API保持相似性而引入的伪函数。It is called asynchronously in the next tick after 它在chunk content have been delivered to the Chromium networking layer. chunk内容被传递到Chromium网络层后的下一个时间点被异步调用。Contrary to the Node.js implementation, it is not guaranteed that 与Node.js实现相反，不能保证在调用chunk content have been flushed on the wire before callback is called.callback之前已经在连线上刷新了chunk内容。
Adds a chunk of data to the request body. 向请求正文中添加一块数据。The first write operation may cause the request headers to be issued on the wire. 第一次写入操作可能会导致在线路上发出请求标头。After the first write operation, it is not allowed to add or remove a custom header.在第一次写入操作之后，不允许添加或删除自定义标头。
request.end([chunk][, encoding][, callback])
chunk(string | Buffer) (optional)encodingstring (optional)callbackFunction (optional)
Sends the last chunk of the request data. Subsequent write or end operations will not be allowed. 发送请求数据的最后一块。不允许进行后续的写入或结束操作。The finish event is emitted just after the end operation.finish事件在结束操作之后立即发出。
request.abort()
Cancels an ongoing HTTP transaction. 取消正在进行的HTTP事务。If the request has already emitted the 如果请求已经发出close event, the abort operation will have no effect. close事件，则中止操作将无效。Otherwise an ongoing event will emit 否则，正在进行的事件将发出abort and close events. abort和close事件。Additionally, if there is an ongoing response object,it will emit the 此外，如果有一个正在进行的响应对象，它将发出aborted event.aborted的事件。
request.followRedirect()
Continues any pending redirection. Can only be called during a 继续任何挂起的重定向。只能在'redirect' event.'redirect'事件期间调用。
request.getUploadProgress()
Returns返回Object:
activeboolean -Whether the request is currently active.请求当前是否处于活动状态。If this is false no other properties will be set如果为false，则不会设置其他属性startedboolean -Whether the upload has started. If this is false both上传是否已开始。如果为currentandtotalwill be set to 0.false，则current和total都将设置为0。currentInteger -The number of bytes that have been uploaded so far到目前为止已上载的字节数totalInteger -The number of bytes that will be uploaded this request将上载此请求的字节数
You can use this method in conjunction with 您可以将此方法与POST requests to get the progress of a file upload or other data transfer.POST请求结合使用，以获取文件上传或其他数据传输的进度。