When I send a file single file use sample code, ,i got a page reload

[kdhly]

When I send a file single file use sample code,i got a page reload,,
I want to stay on the current page what should I do?

code:
onClick(e) {
const fileUpload = this.fileUpload.nativeElement;
fileUpload.onchange = (e) => {
for (let index = 0; index < fileUpload.files.length; index++)
{
const file = fileUpload.files[index];
this.files.push({ data: file, inProgress: false, progress: 0});
}
this.uploadFiles();
};
fileUpload.click();
}

private uploadFiles() {
this.fileUpload.nativeElement.value = '';
this.files.forEach(file => {
this.uploadFile(file);
});
}

uploadFile(file) {
const formData = new FormData();
formData.append('file', file.data);
formData.append('url', "http://localhost:4200/api/upload");
Upload.http({
url: 'http://localhost:4200/api/upload',
data: file
})

html:
<input type="file" #fileUpload id="fileUpload" name="fileUpload" multiple="multiple" accept="image/*" style="display:none;" />

result：
The file was uploaded, but the page was reload.

thank you！