vue--http请求的封装--token

export const FetchHandler = function (url,opt) {
    let paramStr = '';
    let token = '';
    for(key in opt){
        if (opt[key] !== ''){

            if (typeof opt[key] === 'object') {
                paramStr += key + '=' + JSON.stringify(opt[key]) + '&'
            } else {
                paramStr += key + '=' + opt[key] + '&'
            }
        }
    }
    paramStr = paramStr.substring(0,paramStr.length - 1)

    return new Promise((resolve,reject) => {
        AsyncStorage.getItem('token',(error,result)=>{
            token = result;
        }).then(result=>{
            fetch(url, {
                method: "POST",
                mode: "cors",
                headers: {
                    "Content-Type": "application/x-www-form-urlencoded",
                    'token': token
                },
                body: paramStr
            })
                .then((response) => response.json())
                .then(function (response) {
                    resolve(response)
                })
                .catch((reject)=>{
                    reject('request error');
                })
        });

    })
};