javascript - 无法读取handleupload处未定义的属性 'setState'

Question

我正在尝试使用 antd 创建一个带有 fileupload 的表单，但我无法使用 handleupload 函数，出现错误:

Cannot read property 'setState' of undefined
    at handleupload (registertenantform.js:43)

代码是这样的:

import React, { Component } from 'react';
import { Input, Upload , Icon, message} from 'antd';
import Form from '../../components/uielements/form';
import Checkbox from '../../components/uielements/checkbox';
import Button from '../../components/uielements/button';
import Notification from '../../components/notification';
import { adalApiFetch } from '../../adalConfig';

const FormItem = Form.Item;

class RegisterTenantForm extends Component {
    constructor(props) {
        super(props);
        this.state = {TenantId: '', TenantUrl: '', CertificatePassword: '' };
        this.handleChangeTenantUrl = this.handleChangeTenantUrl.bind(this);
        this.handleChangeCertificatePassword = this.handleChangeCertificatePassword.bind(this);
        this.handleChangeTenantId= this.handleChangeTenantId.bind(this);
        this.handleSubmit = this.handleSubmit.bind(this);
    };

    handleChangeTenantUrl(event){
        this.setState({TenantUrl: event.target.value});
    }

    handleChangeCertificatePassword(event){
        this.setState({CertificatePassword: event.target.value});
    }

    handleChangeTenantId(event){
        this.setState({TenantId: event.target.value});
    }

    beforeUpload(file) {
        const isJPG = file.type === 'image/jpeg';
        if (!isJPG) {
          message.error('You can only upload JPG file!');
        }
    }

    handleupload(info){
        //let files = e.target.files;
        if (info.file.status === 'uploading') {
            this.setState({ loading: true });
            return;
        }

        if (info.file.status === 'done') {
            this.setState({ loading: false });
            this.setState({ 'selectedFiles': info.file });
        }

    }

    state = {
            confirmDirty: false,
            loading: false,
    };

    handleSubmit(e){
        e.preventDefault();
        this.props.form.validateFieldsAndScroll((err, values) => {
            if (!err) {
                /*Notification(
                'success',
                'Received values of form',
                JSON.stringify(values)
                );*/

                let data = new FormData();
                //Append files to form data
                data.append("model", JSON.stringify({ "TenantId": this.state.TenantId, "TenantUrl": this.state.TenantUrl, "CertificatePassword": this.state.CertificatePassword }));
                //data.append("model", {"TenantId": this.state.TenantId, "TenantUrl": this.state.TenantUrl, "TenantPassword": this.state.TenantPassword });

                let files = this.state.selectedFiles;
                for (let i = 0; i < files.length; i++) {
                  data.append("file", files[i], files[i].name);
                }

                const options = {
                  method: 'put',
                  body: data,
                  config: {
                    headers: {
                      'Content-Type': 'multipart/form-data'
                    }
                  }
                };

                adalApiFetch(fetch, "/Tenant", options)
                  .then(response => response.json())
                  .then(responseJson => {
                    if (!this.isCancelled) {
                      this.setState({ data: responseJson });
                    }
                  })
                  .catch(error => {
                    console.error(error);
                });
            }
        });      
    }



    render() {

        const uploadButton = (
            <div>
                <Icon type={this.state.loading ? 'loading' : 'plus'} />
                <div className="ant-upload-text">Upload</div>
            </div>
        );

        const { getFieldDecorator } = this.props.form;

        const formItemLayout = {
        labelCol: {
            xs: { span: 24 },
            sm: { span: 6 },
        },
        wrapperCol: {
            xs: { span: 24 },
            sm: { span: 14 },
        },
        };
        const tailFormItemLayout = {
        wrapperCol: {
            xs: {
            span: 24,
            offset: 0,
            },
            sm: {
            span: 14,
            offset: 6,
            },
        },
        };
        return (
            <Form onSubmit={this.handleSubmit}>
                <FormItem {...formItemLayout} label="Tenant Id" hasFeedback>
                {getFieldDecorator('tenantid', {
                    rules: [
                    {
                        required: true,
                        message: 'Please input your tenant id',
                    },
                    ],
                })(<Input name="tenantid" id="tenantid" onChange={this.handleChangeTenantId}/>)}
                </FormItem>
                <FormItem {...formItemLayout} label="Certificate Password" hasFeedback>
                {getFieldDecorator('certificatepassword', {
                    rules: [
                    {
                        required: true,
                        message: 'Please input your password!',
                    }
                    ],
                })(<Input type="certificatepassword" onChange={this.handleChangeCertificatePassword}/>)}
                </FormItem>
                <FormItem {...formItemLayout} label="Tenant admin url" hasFeedback>
                {getFieldDecorator('tenantadminurl', {
                    rules: [
                    {
                        required: true,
                        message: 'Please input your tenant admin url!',
                    }
                    ],
                })(<Input type="tenantadminurl" onChange={this.handleChangeTenantUrl} />)}
                </FormItem>
                <FormItem {...tailFormItemLayout}>
                    <Upload  onChange={this.handleupload} beforeUpload={this.beforeUpload}>

                        <Button>
                            <Icon type="upload" /> Click to Upload
                        </Button>
                    </Upload>
                    <Button type="primary" htmlType="submit">
                        Register tenant
                    </Button>
                </FormItem>
            </Form>
        );
    }
}

const WrappedRegisterTenantForm = Form.create()(RegisterTenantForm);
export default WrappedRegisterTenantForm;

Answer 1

您错过了绑定(bind) handleupload 函数。只需添加

this.handleupload = this.handleupload.bind(this)

在您的RegisterTenantForm构造函数中

或者

您可以使用箭头函数重写 handleupload 函数，如下所示:

handleupload = (info) => {
  //let files = e.target.files;
  if (info.file.status === 'uploading') {
    this.setState({ loading: true });
    return;
  }

  if (info.file.status === 'done') {
    // btw you dont need two separated setState here, you can do
    // it in one setState
    this.setState({
      'selectedFiles': info.file,
      loading: false
    });
  }
}