我是ReactJS的新手,我正在用Firebase构建一个应用程序,在那里我遇到了一个奇怪的场景,lemme解释。
sendtofirebase()
{
db.collection('contacts').add({
name:'faizam',
email:'shdj',
subject:'hdjshj',
message:'hjhdjs',
}).then(()=>{
alert("Data Sent");
}).catch((error)=>{
alert("Error is",error);
});
alert(" from firebase")
}
submitbtn()
{
console.log('Name',this.state.name);
console.log('Email',this.state.email);
console.log('subject',this.state.subject);
console.log('message',this.state.message);
this.sendtofirebase();
alert("from submitbtn");
}
onSubmit={()=>this.submitbtn()}
如果a调用了这样的函数,则数据不会添加到firebase中,但是会显示alert(“ from firebase”)。如果我这样称呼“ onSubmit = {this.submitbtn()}”,那么即使在触发提交按钮之前,数据也会被添加到firebase中。我不明白为什么我要面对这种奇怪的行为。
这是完整的联系表代码。
import React,{Component} from 'react';
从'./firebase'导入{db}; 从“ mdbreact”导入{MDBContainer,MDBRow,MDBCol,MDBBtn,MDBIcon,MDBInput}; ContactForm类扩展Component { 构造函数(道具) { 超级(道具); this.state = { 名称:'', 电子邮件:'', 学科:'', 消息:'',
}
}
sendtofirebase()
{
db.collection('contacts').add({
name:'faizam',
email:'shdj',
subject:'hdjshj',
message:'hjhdjs',
}).then(()=>{
alert("Data Sent");
}).catch((error)=>{
alert("Error is",error);
});
alert(" from firebase")
}
submitbtn()
{
console.log('Name',this.state.name);
console.log('Email',this.state.email);
console.log('subject',this.state.subject);
console.log('message',this.state.message);
this.sendtofirebase();
alert("from submitbtn");
}
render()
{
return(
<>
<div>
<MDBContainer>
<MDBRow>
<MDBCol md="6">
<form className="form" onSubmit={()=>this.submitbtn()}>
<p className="h5 text-center mb-4">Contact Me</p>
<div className="grey-text">
<MDBInput label="Your name" icon="user" group type="text" validate error="wrong"
success="right" />
<MDBInput label="Your email" icon="envelope" group type="email" validate error="wrong"
success="right" />
<MDBInput label="Subject" icon="tag" group type="text" validate error="wrong" success="right" />
<MDBInput type="textarea" rows="2" label="Your message" icon="pencil-alt" />
</div>
<div className="text-center">
<MDBBtn value="submit" type="submit" outline
color="secondary">
Send
<MDBIcon far icon="paper-plane" className="ml-1" />
</MDBBtn>
</div>
</form>
</MDBCol>
</MDBRow>
</MDBContainer>
</div>
</>
);
}
}export default ContactForm;
答案 0 :(得分:0)
我不确定这是否是您的问题,但可能是您的函数使用了错误的this binding
要解决此问题,您应该更改:
sendtofirebase()
{
db.collection('contacts').add({
name:'faizam',
email:'shdj',
subject:'hdjshj',
message:'hjhdjs',
}).then(()=>{
alert("Data Sent");
}).catch((error)=>{
alert("Error is",error);
});
alert(" from firebase")
}
submitbtn()
{
console.log('Name',this.state.name);
console.log('Email',this.state.email);
console.log('subject',this.state.subject);
console.log('message',this.state.message);
this.sendtofirebase();
alert("from submitbtn");
}
收件人:
sendtofirebase = () => {
db.collection('contacts').add({
name:'faizam',
email:'shdj',
subject:'hdjshj',
message:'hjhdjs',
}).then(()=>{
alert("Data Sent");
}).catch((error)=>{
alert("Error is",error);
});
alert(" from firebase")
}
submitbtn = () => {
console.log('Name',this.state.name);
console.log('Email',this.state.email);
console.log('subject',this.state.subject);
console.log('message',this.state.message);
this.sendtofirebase();
alert("from submitbtn");
}
基本上,someFunction = () => {}
将函数放在类的构造函数中-这应该意味着调用this.someFunction()
绝对是指该上下文。