如何使用SQL Login with password credentials在ReportViewer中访问SSRS报表？

using Microsoft.Reporting.WinForms;

private void LoadReport()
{
    reportViewer1.ProcessingMode = ProcessingMode.Remote;
    reportViewer1.ServerReport.ReportServerUrl = new Uri("报表服务器URL");
    reportViewer1.ServerReport.ReportPath = "报表路径";
    reportViewer1.ServerReport.ReportServerCredentials = new CustomReportCredentials("用户名", "密码");
    reportViewer1.RefreshReport();
}

public class CustomReportCredentials : IReportServerCredentials
{
    private string _username;
    private string _password;

    public CustomReportCredentials(string username, string password)
    {
        _username = username;
        _password = password;
    }

    public bool GetFormsCredentials(out Cookie authCookie, out string userName, out string password, out string authority)
    {
        authCookie = null;
        userName = _username;
        password = _password;
        authority = null;
        return false;
    }

    public System.Security.Principal.WindowsIdentity ImpersonationUser
    {
        get { return null; }
    }

    public System.Net.ICredentials NetworkCredentials
    {
        get { return new System.Net.NetworkCredential(_username, _password); }
    }
}

LoadReport();