Javascript 如何在ajax调用中访问Sharepoint REST api

我是sharepoint的新手。当我试图从JavaScript中的ajax调用调用共享点API url时。但是，它不断地失败并抛出错误。我可以说，这是CORS的错误。因此，我在web.config中做了如下更改

<add name="Access-Control-Allow-Origin" value="*" />
<add name="Access-Control-Allow-Headers" value="Content-Type,Accept,X- FORMS_BASED_AUTH_ACCEPTED,crossDomain,credentials " />
<add name="Access-Control-Allow-Methods" value="GET, POST, PUT, DELETE, OPTIONS" />
<add name="Access-Control-Allow-Credentials" value="true" />

$.support.cors = true;
$.ajax({
    url: url,
    type: "GET",
    crossDomain: true,
    dataType: "json",
    headers: { "Accept": "application/json; odata=verbose" },
    xhrFields: { withCredentials: true },
    async: false,
    success: function (data) {
        var items = data.d;
        console.log("Login Name: " + items.LoginName);
        console.log("Email: " + items.Email);
        console.log("ID: " + items.Id);
        console.log("Title: " + items.Title);
    },
    error: function (jqxr, errorCode, errorThrown) {
        console.log(jqxr.responseText);
    }
});

请帮我解决这个问题。我已经试了两天了

更新：

我犯了这个错误

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对飞行前请求的响应未通过访问控制检查：当请求的凭据模式为“包括”时，响应中“访问控制允许来源”标头的值不得为通配符“*”。

使用下面的PowerShell脚本添加web.config修改：

Add-PSSnapin Microsoft.SharePoint.PowerShell -EA 0

$localFarm = Get-SPFarm

$webapp = Get-SPWebApplication "http://sp:12001"

# Remove old web.config modifications of MyAuthenticationProvider
$oldMods = @();
$webapp.WebConfigModifications | ? { $_.Owner -eq "CrossSiteScripting" } | % { 
    $oldMods = $oldMods + $_
}

$oldMods | % { 
    $webapp.WebConfigModifications.Remove($_) 
}

# update the Web Application and apply all existing web.config modifications - this executes the "remove" actions from above
$webapp.Update()
[Microsoft.SharePoint.Administration.SPWebService]::ContentService.ApplyWebConfigModifications()

#Wait until web.config modifications finished by timer job
while( (Get-SPTimerJob | ? { $_.Name -eq "job-webconfig-modification"}) -ne $null ) {
    Write-Host "." -NoNewline
    Start-Sleep 1
}

# New web.config modifications for MyAuthenticationProvider
$myModification1 = new-object Microsoft.SharePoint.Administration.SPWebConfigModification
$myModification1.Path = "configuration/system.webServer/httpProtocol/customHeaders"
$myModification1.Name = "add[@name='Access-Control-Allow-Origin'][@value='http://localhost:31699']"
$myModification1.Sequence = 0
$myModification1.Owner = "CrossSiteScripting"
#0 = for the enum value "SPWebConfigModification.SPWebConfigModificationType.EnsureChildNode"
$myModification1.Type = 0
$myModification1.Value = "<add name='Access-Control-Allow-Origin' value='http://localhost:31699' />"
$webapp.WebConfigModifications.Add($myModification1)

$myModification1 = new-object Microsoft.SharePoint.Administration.SPWebConfigModification
$myModification1.Path = "configuration/system.webServer/httpProtocol/customHeaders"
$myModification1.Name = "add[@name='Access-Control-Request-Method'][@value='GET,POST,HEAD,OPTIONS']"
$myModification1.Sequence = 0
$myModification1.Owner = "CrossSiteScripting"
$myModification1.Type = 0
$myModification1.Value = "<add name='Access-Control-Request-Method' value='GET,POST,HEAD,OPTIONS' />"
$webapp.WebConfigModifications.Add($myModification1)

$myModification1 = new-object Microsoft.SharePoint.Administration.SPWebConfigModification
$myModification1.Path = "configuration/system.webServer/httpProtocol/customHeaders"
$myModification1.Name = "add[@name='Access-Control-Request-Headers'][@value='Content-Type,Authorization']"
$myModification1.Sequence = 0
$myModification1.Owner = "CrossSiteScripting"
$myModification1.Type = 0
$myModification1.Value = "<add name='Access-Control-Request-Headers' value='Content-Type,Authorization' />"
$webapp.WebConfigModifications.Add($myModification1)

$myModification1 = new-object Microsoft.SharePoint.Administration.SPWebConfigModification
$myModification1.Path = "configuration/system.webServer/httpProtocol/customHeaders"
$myModification1.Name = "add[@name='Access-Control-Allow-Credentials'][@value='true']"
$myModification1.Sequence = 0
$myModification1.Owner = "CrossSiteScripting"
$myModification1.Type = 0
$myModification1.Value = "<add name='Access-Control-Allow-Credentials' value='true' />"
$webapp.WebConfigModifications.Add($myModification1)

$webapp.Update()
[Microsoft.SharePoint.Administration.SPWebService]::ContentService.ApplyWebConfigModifications()

#Wait until web.config modifications finished by timer job
while( (Get-SPTimerJob | ? { $_.Name -eq "job-webconfig-modification"}) -ne $null ) {
    Write-Host "." -NoNewline
    Start-Sleep 1
}

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参考资料：

谢谢您的评论。但是，实际上我是从sharepoint获取XML格式的数据，而不是JSON格式的数据。那么我需要在JavaScript中修改哪些内容呢？修改标题：标题：{“接受”：“application/atom+xml”}，

$.support.cors = true;
$.ajax({
    url: url,
    type: "GET",
    crossDomain: true,
    dataType: "json",
    headers: { "Accept": "application/json; odata=verbose" },
    xhrFields: { withCredentials: true },
    async: false,
    success: function (data) {
        var items = data.d;
        console.log("Login Name: " + items.LoginName);
        console.log("Email: " + items.Email);
        console.log("ID: " + items.Id);
        console.log("Title: " + items.Title);
    },
    error: function (jqxr, errorCode, errorThrown) {
        console.log(jqxr.responseText);
    }
});