React-Native post和get请求

post：

 fetchData (title) {
     fetch(REQUEST_URL, {
     method: 'POST',
     headers: {
     'Accept': 'application/json',
     'Content-Type': 'application/json'
     },
     body: JSON.stringify({
       email: un,
       password: pw
     })
   })
     .then((response) => response.json())
     .then((responseData) => {
       if (responseData['isOK']==='ok') {
         ToastAndroid.show('登录成功', ToastAndroid.SHORT)
       } else {
         ToastAndroid.show('登录失败', ToastAndroid.SHORT)
       }
     })
     .done()
   }

   responseData (response) {
     return response.result.data
   }

get：

 fetchData: function () {
     fetch(REQUEST_URL)
       .then((response) => response.json())
       .then((responseData) => {
         this.setState({
           dataSource: this.state.dataSource.cloneWithRows(responseData),
           loaded: true
         })
       })
       .done()
   },