如何在angular中为表单添加验证

Question

我有两个反应形式的输入。例如：出生日期和日期，我想将验证添加到日期中，该日期的最小值必须是出生日期或更多。我该如何解决？我试着这样做，但不起作用。Validators.min(this.myForm.value.birthDate);

Answer 1

如果你已经附加了Typescript文件，但我在这里附加了自定义验证器的代码，那会更有帮助。请根据您的代码调整表单名称和字段。简而言之，对于这些kinfd验证，您必须编写自定义验证。内置验证在这里没有帮助。

export class CustomeDateValidators {
static fromToDate(fromDateField: string, toDateField: string, errorName: string = 'fromToDate'): ValidatorFn {
return (formGroup: AbstractControl): { [key: string]: boolean } | null => {
const fromDate = formGroup.get(fromDateField).value;
const toDate = formGroup.get(toDateField).value;
// Ausing the fromDate and toDate are numbers. In not convert them first after null check
if ((fromDate !== null && toDate !== null) && fromDate > toDate) {
return {[errorName]: true};
}
return null;
};
}
}
/*--- implementations ---*/
this.form = this.fb.group({
fromDate: null,
toDate: null,
}, { validator: [
//Default error with this validator:  {fromToDate: true}
CustomeDateValidators.fromToDate('fromDate', 'toDate')

// For custome error name like: {customeErrorName: true}, pass third optional parameter with custome name
// CustomeDateValidators.fromToDate('fromDate', 'toDate', 'customeErrorName')
]});