Javascript 无法通过POST api发送图像

我有一个要求，我需要从手机库/摄像头中选择一个图像，并通过POST api上传到服务器。我可以从库中加载图像，但在使用post请求发送图像时出错

我的HTML代码：

<p (click)="selectImage()">Add an attachment</p></ion-item>

这是我通过api发送图像数据时在控制台中遇到的错误。

---

您应该使用FormData，并在html中使用输入类型=“文件”

您需要以FormData的形式追加数据

 formData.append('file', f)

下面是输入验证的完整示例

您的服务将是这样的

public uploadFile(file: FormData): Observable {
        const url = `${this.apiUrl}/upload`;
        return this.http.post(url, file);
    }

if (this.form.valid && files[0].name.split('.').pop() === 'excel') {
      const formData = new FormData();

      Array.from(files).forEach(f => formData.append('file', f));

      this.uploadService.uploadPdfToGetBase64(formData).subscribe(
        (res: any) => {
          this.myFileInput.nativeElement.value = '';
        },
        (errorRes: HttpErrorResponse) => {
          alert('error occured');
          this.form.reset();
          this.myFileInput.nativeElement.value = '';
        }
      );
    } else {
      alert('Invalid file selected. Only excel is allowed');
    }

<form [formgroup]="form">
  <div class="form-group">
    <label for="file"></label>
    <input type="file" #fileinput="" formcontrolname="fileContact" id="file" required="" (change)="handleFileInput($event.target.files)">
    <button type="button" class="btn btn-info" (click)="clearSelection()">Clear</button>
  </div>
</form>

您的提交函数如下所示

public uploadFile(file: FormData): Observable {
        const url = `${this.apiUrl}/upload`;
        return this.http.post(url, file);
    }

if (this.form.valid && files[0].name.split('.').pop() === 'excel') {
      const formData = new FormData();

      Array.from(files).forEach(f => formData.append('file', f));

      this.uploadService.uploadPdfToGetBase64(formData).subscribe(
        (res: any) => {
          this.myFileInput.nativeElement.value = '';
        },
        (errorRes: HttpErrorResponse) => {
          alert('error occured');
          this.form.reset();
          this.myFileInput.nativeElement.value = '';
        }
      );
    } else {
      alert('Invalid file selected. Only excel is allowed');
    }

<form [formgroup]="form">
  <div class="form-group">
    <label for="file"></label>
    <input type="file" #fileinput="" formcontrolname="fileContact" id="file" required="" (change)="handleFileInput($event.target.files)">
    <button type="button" class="btn btn-info" (click)="clearSelection()">Clear</button>
  </div>
</form>

您的HTML如下所示

public uploadFile(file: FormData): Observable {
        const url = `${this.apiUrl}/upload`;
        return this.http.post(url, file);
    }

if (this.form.valid && files[0].name.split('.').pop() === 'excel') {
      const formData = new FormData();

      Array.from(files).forEach(f => formData.append('file', f));

      this.uploadService.uploadPdfToGetBase64(formData).subscribe(
        (res: any) => {
          this.myFileInput.nativeElement.value = '';
        },
        (errorRes: HttpErrorResponse) => {
          alert('error occured');
          this.form.reset();
          this.myFileInput.nativeElement.value = '';
        }
      );
    } else {
      alert('Invalid file selected. Only excel is allowed');
    }

<form [formgroup]="form">
  <div class="form-group">
    <label for="file"></label>
    <input type="file" #fileinput="" formcontrolname="fileContact" id="file" required="" (change)="handleFileInput($event.target.files)">
    <button type="button" class="btn btn-info" (click)="clearSelection()">Clear</button>
  </div>
</form>

清楚的

请尝试遵循http.post…：

，{data:formData}，

@YunusEmreBAKAÇ尝试过，但似乎不起作用，仍然收到与您发送的JSON不同的错误。不要对你的api撒谎我已经更新了我的问题并将对象正确地传递给了我的api。那里的服务器需要文件