如何在上传前预览图像使用ngx文件放入angular 6?
我使用“文件拖放”标签在Angular 6上拖放图像如何在上传前预览图像使用ngx文件放入angular 6?,angular,file-upload,angular6,ng-file-upload,Angular,File Upload,Angular6,Ng File Upload,我使用“文件拖放”标签在Angular 6上拖放图像 <file-drop headertext="{{adCrud.uploadMediaText}}" (onFileDrop)="dropped($event)" (onFileOver)="fileOver($event)" customstyle="filedrop" customstyle="adMedia" (onFileLeave)="fileLeave($event)" > 注意:我正在尝试
<file-drop headertext="{{adCrud.uploadMediaText}}"
(onFileDrop)="dropped($event)" (onFileOver)="fileOver($event)"
customstyle="filedrop" customstyle="adMedia"
(onFileLeave)="fileLeave($event)" >
注意:我正在尝试实现以下方法,但能否找到event.target?from(onFileDrop)=“已删除($event)”
media1change(事件){
if(event.target.files&&event.target.files[0]){
const reader=new FileReader();
//tslint:禁用下一行:无阴影变量
reader.onload=(事件:ProgressEvent)=>{
this.adCrud.media1=(event.target).result;
////console.log(this.profile);
//这是uploadmedia1();
};
reader.readAsDataURL(event.target.files[0]);
}
this.media1File=event.target.files[0];
this.uploadmedia1();}
文件条目是FileSystemEntry的一个实例,但如果上载的是文件而不是文件夹,则文件条目
实际上是一个FileSystemFileEntry
实例。这意味着它有file()
方法,您可以这样做:
imageDropped($event: UploadEvent) {
const droppedFile = $event.files[0];
const fileEntry = droppedFile.fileEntry as FileSystemFileEntry;
const reader = new FileReader();
fileEntry.file(file => {
reader.readAsDataURL(file);
reader.onload = () => {
this.imageUrl = reader.result;
};
});
}
您的最后一个注释对我来说似乎不是很清楚。//我正在尝试像(更改)=“myFuc($event)”一样实现,但是(onFileDrop)=“droped($event)”失败,并且错误为event.target或event.target.files[0]为空。我只想显示从(onFileDrop)=“droped($event)”获取的图像文件在它上传到服务器之前,你能提供一个例子吗
media1change(event) {
if (event.target.files && event.target.files[0]) {
const reader = new FileReader();
// tslint:disable-next-line:no-shadowed-variable
reader.onload = (event: ProgressEvent) => {
this.adCrud.media1 = (<FileReader>event.target).result;
// // console.log(this.profile);
// this.uploadmedia1();
};
reader.readAsDataURL(event.target.files[0]);
}
this.media1File = event.target.files[0];
this.uploadmedia1(); }
imageDropped($event: UploadEvent) {
const droppedFile = $event.files[0];
const fileEntry = droppedFile.fileEntry as FileSystemFileEntry;
const reader = new FileReader();
fileEntry.file(file => {
reader.readAsDataURL(file);
reader.onload = () => {
this.imageUrl = reader.result;
};
});
}
<img [src]="**imageUrlPREVIEW**">
imageUrlPREVIEW;
...
const droppedFile = event.files[0];
const fileEntry = droppedFile.fileEntry as FileSystemFileEntry;
const reader = new FileREader();
fileEntry.file((file: File) => {
reader.readASDAtaURL(file);
reader.onload = () => {
**this.imageUrlPREVIEW**= reader.result;
};
});