Question

我在项目中使用的是Angular 5.2版本，并且通过将默认responseType更改为具有新功能的blob遇到了问题。

现在我想将responseType更改为blob以下载excel文件，但是它对我不起作用。

在我的项目中，我将包装类创建为CustomHttpClient以进行Get或Post调用。

CustomHttpClient类看起来像这样：-

    export interface IRequestOptions {

    headers?: HttpHeaders;
    observe?: 'body';
    params?: HttpParams;
    reportProgress?: boolean;
    responseType?: 'json';
    withCredentials?: boolean;
    body?: any;
}


/*Custom HttpClient Class for making the WebAPI calls.*/
export class CustomHttpClient {

    _defaultHeaderType = new HttpHeaders({ 'Content-Type': 'application/json' });

    // Extending the HttpClient through the Angular DI.
    public constructor(public _http: HttpClient) {

    }

  public Get<T>(endPoint: string, options?: IRequestOptions): Observable<T> {
        if (options == undefined) {
            options = <IRequestOptions>{};
            options.headers = this._defaultHeaderType
        }

        options.headers = this.injectClient(options.headers);
        return this._http.get<T>(endPoint, options);
    }

    public GetBlob<T>(endPoint: string, options?: IRequestOptions): Observable<T> {
        if (options == undefined) {
            options = <IRequestOptions>{};
            options.headers = this._defaultHeaderType
        }

        //This line is giving error
         options.responseType = 'blob';

        options.headers = this.injectClient(options.headers);
        return this._http.get<T>(endPoint, options);
    }
}

现在，我想调用GetBlob函数，并将responseType更改为'blob'。但这向我显示了错误“类型“ blob”无法分配给类型“ Json”“。

从组件服务类中，我这样调用fn：-

downloadTemplate(): Observable<any> {
    let opt = {
        headers: new HttpHeaders({ 'Content-Type': 'application/json', 'Accept': 'application/xlsx'}),
        options: new RequestOptions({ responseType: ResponseContentType.Blob })
    }

    return this._httpObj.GetBlob(this._baseUrl + 'DownloadTemplate', opt);
}

Answer 1

最近有同样的问题，希望他们能在一段时间后解决。我使用Object.assign作为解决方法：

public class UARTCommunicationProvider
{
    SerialDevice _serialPort;
    private DataReader _serialPortReader;
    private DataWriter _serialPortWriter;
    private CancellationTokenSource _serialPortReadWriteCTS = null;
    public UARTCommunicationProvider()
    {
        _serialPortReadWriteCTS = new CancellationTokenSource();
    }
    public async Task<bool> ConnectAsync(string comportId)
    {
        _serialPort = await SerialDevice.FromIdAsync(comportId);

        if (_serialPort != null)
        {
            _serialPort.WriteTimeout = TimeSpan.FromMilliseconds(50);
            _serialPort.ReadTimeout = TimeSpan.FromMilliseconds(50);
            _serialPort.BaudRate = 9600;
            _serialPort.Parity = SerialParity.None;
            _serialPort.StopBits = SerialStopBitCount.One;
            _serialPort.DataBits = 8;
            _serialPort.Handshake = SerialHandshake.None;

            _serialPortReader = new DataReader(_serialPort.InputStream);
            // Set InputStreamOptions to complete the asynchronous read operation when one or more bytes is available
            _serialPortReader.InputStreamOptions = InputStreamOptions.Partial;
            _serialPortWriter = new DataWriter(_serialPort.OutputStream);
            return true;
        }
        else
        {
            return false;
        }
    }

    public async void CollectData()
    {
        var command = "FL 1\n";
        while (true)
        {
            var response = await ResponseForCommandAsync(command);
            Debug.WriteLine(response)

        }
    }

    public void Disconnect()
    {
        try
        {
            _serialPort?.Dispose(); //Stuck at this point when I try to dispose after reading few chunks of data from serial port
            _serialPortReadWriteCTS.Cancel();
            _serialPort = null;
        }
        catch (Exception ex)
        {

            throw;
        }
    }

    public async Task<string> ResponseForCommandAsync(string command)
    {
        string response = string.Empty;
        if (_serialPort != null)
        {
            // Load the text from the sendText input text box to the dataWriter object
            _serialPortWriter.WriteString(command);
            UInt32 bytesWritten = await _serialPortWriter.StoreAsync();
            if (bytesWritten > 0)
            {
                bytecount = bytecount + (int)bytesWritten;
                _logger.WriteLine("Data Sent Successfully", AEIoTCommon.Common.LoggingType.Verbose);
                response = await ReadAsync();
            }
        }

        return response;
    }

    private async Task<string> ReadAsync()
    {
        string valueRead = null;
        Task<UInt32> loadAsyncTask;

        uint ReadBufferLength = 1024;

        try
        {
            CancellationToken cancellationToken = _serialPortReadWriteCTS.Token;

            //If task cancellation was requested, comply
            cancellationToken.ThrowIfCancellationRequested();

            using (var childCancellationTokenSource = new CancellationTokenSource(3000))
            {
                // Create a task object to wait for data on the serialPort.InputStream
                loadAsyncTask = _serialPortReader.LoadAsync(ReadBufferLength).AsTask(childCancellationTokenSource.Token);

                // Launch the task and wait
                UInt32 bytesRead = await loadAsyncTask;
                if (bytesRead > 0)
                {
                    //byte[] buffer = new byte[bytesRead];
                    var value = _serialPortReader.ReadString(bytesRead);

                    valueRead = value;
                }
            }
        }
        catch (TaskCanceledException ex)
        {
            Disconnect();
        }


        return valueRead;
    }
}

这样您就可以作弊ts类型检查。

Answer 2

尝试更改您的IRequestOptions接口，以使响应类型为字符串类型。像这样：

  export interface IRequestOptions {

    headers?: HttpHeaders;
    observe?: 'body';
    params?: HttpParams;
    reportProgress?: boolean;
    responseType?: string;
    withCredentials?: boolean;
    body?: any;
}

Angular 5.2自定义HttpClient类-无法将responseType更改为blob

2 个答案: