如何在angular中上传一个文件，并为文件使用formData

Question

我已经成功地发出了post请求，但在请求体中的formData是空的。我不知道是什么原因

trigger() {
let element = document.getElementById('upload_file') as HTMLInputElement;
element.click();
}

onChange(file: any) {
this.FILE = file.files[0];
this.fileName = file.files[0].name;
}

uploadDocument() {
this.document = new Document();
this.document.value= this.VALUE;
.
.
.
this.document.value= this.VALUE;
let document = JSON.stringify(this.document);
const formData: FormData = new FormData();
formData.append('file', this.FILE, this.FILE.name);
return this.http.post(this.baseURL + '/rest/document/', {document, formData}).subscribe((data: any) => {
this.connection.creating = false;
})
}

Answer 1

将document字段设置为FormData的一部分

let document = JSON.stringify(this.document);
const formData: FormData = new FormData();
formData.append('file', this.FILE, this.FILE.name);
formData.append('document', document);
return this.http.post(this.baseURL + '/rest/document/', formData).subscribe((data: any) => {
this.connection.creating = false;
})
}