PowerShell模拟Postman调用Graph API设置SharePoint站点权限报错

错误点 #

• 调用POST接口时传入了未序列化的PowerShell哈希表对象作为请求体：你已经提前将请求体序列化为JSON字符串存储在$bodyTxt变量中，但实际调用Invoke-WebRequest时传入的是原始哈希表$body，Graph API仅接收JSON格式的请求体，所以返回Bad Request错误。
• 请求头中的Content-Type字段配置不规范：你在Headers表中定义的键名为ContentType，正确的HTTP头字段名应为Content-Type，也可以直接通过Invoke-WebRequest的-ContentType参数指定，避免拼写错误。

修正后的代码段 #

cls

# https://learn.microsoft.com/en-us/graph/api/site-get-permission?view=graph-rest-1.0&tabs=http

$secret = "xxx.5i2v"
$clientid="xx-45f3-464f-xx-xx"
$tenantid="xx-x-4f1f-xx-x"


$Body = @{
    'tenant' = $tenantid
    'client_id' = $clientid
    'scope' = 'https://graph.microsoft.com/.default'
    'client_secret' = $secret
    'grant_type' = 'client_credentials'
}

$Params = @{
    'Uri' = "https://login.microsoftonline.com/$tenantid/oauth2/v2.0/token"
    'Method' = 'Post'
    'Body' = $Body
    'ContentType' = 'application/x-www-form-urlencoded'
}

$AuthResponse = Invoke-RestMethod @Params

$Headers = @{
    'Authorization' = "Bearer $($AuthResponse.access_token)"    
}

# 权限查询请求保持不变
$Result = Invoke-RestMethod -Uri 'https://graph.microsoft.com/v1.0/sites/xx-53D2-xx-xx-xx/permissions' -Headers $Headers
$bodyTxt = $Result | ConvertTo-Json -Depth 100
write-host $bodyTxt 


$body = @{
    roles               = @("write")    
    grantedToIdentities = @( @{
            application = @{
                displayName = "Test 7"                
                id = "xx-45f3-xx-aac4-xx"                
            }
        })
}

$bodyTxt = $body | ConvertTo-Json -Depth 100

# 修正后的POST请求：传入序列化后的JSON字符串，显式指定Content-Type
Invoke-WebRequest -Uri 'https://graph.microsoft.com/v1.0/sites/xx-53D2-xx-xx-xx/permissions' -Method POST -Body $bodyTxt -Headers $Headers -ContentType 'application/json'

内容的提问来源于stack exchange，提问作者Thomas Segato