Angular4表单验证代码详解
人气:0背景:
最近在itoo页面调整的时候,发现页面表单或者是文本框没有做基本的判断操作,所以着手demo一篇,希望对大家有帮助!!
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1.创建表单组件:
ng g c login1
2.1单规则验证:
<label>用户名:</label> <input type="text" #userNameRef=ngModel [(ngModel)]=userName required> <span [style.color]="userNameRef.valid ? 'black':'red'">{{userNameRef.valid}}</span>
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效果:
2.2.多规则验证:(不能为空,用户名和密码的长度)
<div class="form-group"> <label>用户名:</label> <input type="text" class="form-control" #userNameRef=ngModel minlength="3" maxlength="8" [(ngModel)]=userName required> <span [style.color]="userNameRef.valid ? 'black':'red'">{{userNameRef.valid}}</span> </div>
错误原因提示方式:
<div class="form-group"> <label>用户名:</label> <input type="text" class="form-control" #userNameRef=ngModel minlength="3" maxlength="8" [(ngModel)]=userName required> <span [style.color]="userNameRef.valid ? 'black':'red'">{{userNameRef.errors|json}}</span> <div *ngIf="userNameRef.errors?.required">this is required</div> <div *ngIf="userNameRef.errors?.minlength">should be 3 chacaters</div> </div>
效果:
###:初始化,没有输入数据:
###:输入数据,但是长度小于3:
###:合法输入:
当然这里有一个问题,就是合法的时候usernameRef.errors=null,
但是用户看起来不太美观,所以就需要判断当usernameRef.errors=null
的时不出现:
<span [style.color]="userNameRef.valid ? 'black':'red'" *ngIf="userNameRef.errors!=null">{{userNameRef.errors|json}}</span>
具体实例登陆代码:
<form #form="ngForm" (ngSubmit)="form.form.valid && submit(form.value)" novalidate class="form-horizontal" role="form"> <div class="form-group" [ngClass]="{ 'has-error': form.submitted && !userName.valid }"> <label class="col-sm-2 control-label">用户名:</label> <div class="col-sm-10"> <input required name="userName" [(ngModel)]="user.userName" #userName="ngModel" type="text" class="form-control" placeholder="请输入用户名..."> <div *ngIf="form.submitted && !userName.valid" class="text-danger">用户名必须输入!</div> </div> </div> <div class="form-group"> <label class="col-sm-2 control-label">密码:</label> <div class="col-sm-10" [ngClass]="{'has-error': form.submitted && !password.valid }"> <input required minlength="8" maxlength="12" [(ngModel)]="user.password" name="password" #password="ngModel" type="password" class="form-control" placeholder="请输入密码..."> <div *ngIf="form.submitted && !password.valid" class="text-danger">密码必须输入,至少要8位!</div> </div> </div> <div class="form-group"> <div class="col-sm-offset-2 col-sm-10"> <button type="submit" class="btn btn-success">登录</button> </div> </div> </form>
login.component:
import { Component, OnInit} from '@angular/core'; import{UserModel} from '../model/user.model';//引入了usermodel @Component({ selector: 'app-login', templateUrl: './login.component.html', styleUrls: ['./login.component.css'] }) export class LoginComponent implements OnInit { constructor() { } //定义user为Usermodel private user=new UserModel(); ngOnInit() { } /** * 登陆事件 * @param form 表单中的输入值 */ submit(form){ if(form.username=="1"&&form.password=="12345678"){ alert("登录成功了"); }else{ alert("非法用户"); } } }
3.userModel:
export class UserModel{ userName:string; password:string; }
效果:
1.未填时点击登陆:
2.输入登陆:
3.非法用户:
总结
以上所述是小编给大家介绍的Angular4表单验证代码详解,希望对大家有所帮助,如果大家有任何疑问欢迎给我留言,小编会及时回复大家的!
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