带有 Unicode 参数的 C++ Builder TRestRequest

Question

我正在使用 TRestRequest 从服务器获取数据。我需要用 Unicode 字符串值填充参数："ôpen"。但是，我使用此 Unicode 字符串作为查询参数调用 Execute 时遇到崩溃。

我的代码：

    RESTRequest->ResetToDefaults();
    RESTRequest->AddParameter("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8 ", TRESTRequestParameterKind::pkHTTPHEADER);
    //  Get Indexing Status
    RESTRequest->Resource = "XXX/collection1"+ Form1->teReuqestHandler->Text+"?";
    RESTRequest->Method = rmGET;
    // replace all space in name field with '\ '
    UnicodeString lcQuery = Form1->teQuery->Text; // this value should be support french language or ...
    // Body
    RESTRequest->AddParameter("q",lcQuery, TRESTRequestParameterKind::pkGETorPOST);
    // Run
    String str1 = RESTRequest->GetFullRequestURL();
    RESTRequest->Execute(); // here when pass "ôpen" to lcQuery, it crash

如何正确地将 "ôpen" 添加到我的 URL？

Answer 1

Content-Type: application/x-www-form-urlencoded; charset=UTF-8 HTTP header 在 GET 请求中没有意义，仅在 POST 请求中。

Embarcadero 的 REST 框架无法正确处理 non-ASCII 字符集。尽管它在内部使用 Indy，但它不使用 Indy 的字符集处理。因此，为了发送 UTF-8 编码的数据，您必须：

手动将 UnicodeString 编码为 UTF-8，然后将 UTF-8 八位字节放回 UnicodeString，以便 TRESTRequest 可以发送它们：

UnicodeString EncodeAsUtf8(const UnicodeString &s)
{
    UTF8String utf8 = s;
    UnicodeString ret;
    ret.SetLength(utf8.Length());
    for (int x = 1; x <= utf8.Length(); ++x)
        ret[x] = (WideChar) utf8[x];
    return ret;
}

...

RESTRequest->ResetToDefaults();
RESTRequest->Method = rmGET;
RESTRequest->Resource = L"XXX/collection1" + Form1->teReuqestHandler->Text;
RESTRequest->AddParameter(L"q", EncodeAsUtf8(Form1->teQuery->Text), TRESTRequestParameterKind::pkGETorPOST);
String str1 = RESTRequest->GetFullRequestURL();
RESTRequest->Execute();

自己编码参数数据：

#include <IdGlobal.hpp>
#include <IdURI.hpp>

RESTRequest->ResetToDefaults();
RESTRequest->Method = rmGET;
RESTRequest->Resource = L"XXX/collection1" + Form1->teReuqestHandler->Text;
RESTRequest->AddParameter(L"q", TIdURI::ParamsEncode(Form1->teQuery->Text, IndyTextEncoding_UTF8), TRESTRequestParameterKind::pkGETorPOST, TRESTRequestParameterOptions() << TRESTRequestParameterOption::poDoNotEncode);
String str1 = RESTRequest->GetFullRequestURL();
RESTRequest->Execute();

或者：

#include <IdGlobal.hpp>
#include <IdURI.hpp>

RESTRequest->ResetToDefaults();
RESTRequest->Method = rmGET;
RESTRequest->Resource = L"XXX/collection1" + Form1->teReuqestHandler->Text + L"?q={q}";
RESTRequest->AddParameter(L"q", TIdURI::ParamsEncode(Form1->teQuery->Text, IndyTextEncoding_UTF8), TRESTRequestParameterKind::pkURLSEGMENT, TRESTRequestParameterOptions() << TRESTRequestParameterOption::poDoNotEncode);
String str1 = RESTRequest->GetFullRequestURL();
RESTRequest->Execute();

否则，切换到 Indy 的 TIdHTTP 组件：

UnicodeString Response = IdHTTP1->Get(L"http://server/XXX/collection1" + Form1->teReuqestHandler->Text + L"?q=" + TIdURI::ParamsEncode(Form1->teQuery->Text, IndyTextEncoding_UTF8));

带有 Unicode 参数的 C++ Builder TRestRequest

C++ Builder TRestRequest with Unicode parameter

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