问题描述
我想在Flutter中发送获取请求请求。但是我一直在找回HTML代码。
在邮递员中，我必须指定accept: application/json才能获取JSON。但是我关注的教程没有提到。
这是我的下面的代码
void getData() async {
http.Response response = await http.get(
'https://libriboo.com/api/landing');
// var res = json.decode(response.body);
print(response.body);
}
我得到了
I/flutter ( 5134): <head>
I/flutter ( 5134): <title>Libri</title>
I/flutter ( 5134): <!-- Required meta tags -->
I/flutter ( 5134): <meta charset="utf-8">
I/flutter ( 5134): <meta name="viewport" content="width=device-width,initial-scale=1,shrink-to-fit=no">
I/flutter ( 5134): <link rel="shortcut icon" type="image/png" href=".\images\favicon.png">
I/flutter ( 5134): <!-- Bootstrap CSS -->
I/flutter ( 5134): <link rel="stylesheet" href=".\assets\css\style.css">
I/flutter ( 5134): <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" integrity="sha384-ggOyR0iXCbMQv3Xipma34MD+dH/1fQ784/j6cY/iJTQUOhcWr7x9JvoRxT2MZw1T" crossorigin="anonymous">
I/flutter ( 5134): <link href="https://stackpath.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css" rel="stylesheet" integrity="sha384-wvfXpqpZZVQGK6TAh5PVlGOfQNHSoD2xbE+QkPxCAFlNEevoEH3Sl0sibVcOQVnN" crossorigin="anonymous">
I/flutter ( 5134): <link rel="stylesheet" href=".\assets\css\bootstrap.css">
I/flutter ( 5134): <link rel="stylesheet" href=".\assets\css\font-awesome.css">
I/flutter ( 5134): <script src="..\assets\js\script.js"></script>
I/flutter ( 5134):
I/flutter ( 5134):
I/flutter ( 5134):
I/flutter ( 5134): </head
解决方法
xtremeCODE，您可以在content type中指定header，如下所示：
void getData() async {
http.Response response = await http.get(
'https://libriboo.com/api/landing',headers:{
"Content-Type":"application/json"
});
print(response.body);
}
似乎在请求过程中出现服务器端错误，请尝试打印statusCode或尝试类似的操作
#include <utility>
// lambda_t is the type of thing we want to call.
// capture_t is the type of a helper object that
// contains all all parameters meant to be passed to the callable
template< class lambda_t,class capture_t >
struct CallObject {
lambda_t m_lambda;
capture_t m_args;
typedef decltype( m_args(m_lambda) ) return_t;
//Construct the CallObject by perfect forwarding which is
//neccessary as they may these are lambda which will have
//captured objects and we dont want uneccessary copies
//while passing these around
CallObject( lambda_t&& p_lambda,capture_t&& p_args ) :
m_lambda{ std::forward<lambda_t>(p_lambda) },m_args { std::forward<capture_t>(p_args) }
{
}
//Applies the arguments captured in m_args to the thing
//we actually want to call
return_t invoke() {
return m_args(m_lambda);
}
//Deleting special members for testing purposes
CallObject() = delete;
CallObject( const CallObject& ) = delete;
CallObject( CallObject&& ) = delete;
CallObject& operator=( const CallObject& ) = delete;
CallObject& operator=( CallObject&& ) = delete;
};
//Factory helper function that is needed to create a helper
//object that contains all the paremeters required for the
//callable. Aswell as for helping to properly templatize
//the CallObject
template< class lambda_t,class ... Tn >
auto Factory( lambda_t&& p_lambda,Tn&& ... p_argn ){
//Using a lambda as helper object to contain all the required paramters for the callable
//This conviently allows for storing value,references and so on
auto x = [&p_argn...]( lambda_t& pp_lambda ) mutable -> decltype(auto) {
return pp_lambda( std::forward<decltype(p_argn)>(p_argn) ... );
};
typedef decltype(x) xt;
//explicit templetization is not needed in this case but
//for the sake of readability it needed here since we then
//need to forward the lambda that captures the arguments
return CallObject< lambda_t,xt >( std::forward<lambda_t>(p_lambda),std::forward<xt>(x) );
}
int main(){
auto xx = Factory( []( int a,int b ){
return a+b;
},10,3 );
int q = xx.invoke();
return q;
}