如何在 reactjs ES6 中使用 JSONArray 上的 .map() 函数

Question

我有一个服务器返回的JSONArray。我想在上面使用 .map((，以便我可以获取该数组中存在的每个对象的键、值对。我编写了以下代码，但出现错误"files.map 不是函数"。任何人都可以帮我解决这个问题吗？

showUploadedFiles()
{
const page = 1;
const items_per_page = this.state.event.file_ids.length;
getAllTaskFiles(this.state.event.id, page, items_per_page).then((allFiles) => {
this.renderUploadedFiles(allFiles);
});
}
renderUploadedFiles(files)
{
let details = null;
details = files.map((singleFile) => {
return (
<div>
<a href="#" >{singleFile.filename}</a> 
<a href="#" >{singleFile.file_path}</a>
</div>
);
});
}  

我的JSONArray是：

[{"file_id": 5224879255191552, "filename": "children_walk_friends_forest_116878_3840x2160.jpg", "file_path": "/api/files/encoded_gs_file%3AdHJhY2tpbmctYXBpL3YxL2FjY291bnRzLzU2Mjk0OTk1MzQyMTMxMjAvdGFza3MvNDk5NjE4MDgzNjYxNDE0NC81MjI0ODc5MjU1MTkxNTUyL2Zha2UtemRNeklhZ1RTYl9PN3RXY2pXbkhVQT09"}, {"file_id": 4943404278480896, "filename": "banner_old.jpg", "file_path": "/api/files/encoded_gs_file%3AdHJhY2tpbmctYXBpL3YxL2FjY291bnRzLzU2Mjk0OTk1MzQyMTMxMjAvdGFza3MvNDk5NjE4MDgzNjYxNDE0NC80OTQzNDA0Mjc4NDgwODk2L2Zha2UtcmJjbDBVdVFzVmZkMjRtRUV2ME1xZz09"}] 

Answer 1

正如其他用户指出的那样，您必须使用JSON.parse()从字符串中获取对象。这是代码片段，将文件存储在数组中。

const str = '[{"file_id": 5224879255191552, "filename": "children_walk_friends_forest_116878_3840x2160.jpg", "file_path": "/api/files/encoded_gs_file%3AdHJhY2tpbmctYXBpL3YxL2FjY291bnRzLzU2Mjk0OTk1MzQyMTMxMjAvdGFza3MvNDk5NjE4MDgzNjYxNDE0NC81MjI0ODc5MjU1MTkxNTUyL2Zha2UtemRNeklhZ1RTYl9PN3RXY2pXbkhVQT09"}, {"file_id": 4943404278480896, "filename": "banner_old.jpg", "file_path": "/api/files/encoded_gs_file%3AdHJhY2tpbmctYXBpL3YxL2FjY291bnRzLzU2Mjk0OTk1MzQyMTMxMjAvdGFza3MvNDk5NjE4MDgzNjYxNDE0NC80OTQzNDA0Mjc4NDgwODk2L2Zha2UtcmJjbDBVdVFzVmZkMjRtRUV2ME1xZz09"}]';
const files = JSON.parse(str);
const details = files.map((singleFile) => {
return (
`<div>
<a href="#">{singleFile.filename}</a> 
<a href="#">{singleFile.file_path}</a>
</div>`
);
});
console.log(details);

.as-console-wrapper { max-height: 100% !important; top: 0; }