feat: improve code login demo (#5154)

* feat: add some method in formApi

* fix: VbenPinInput style with small screen

* chore: improve code login demo

packages/@core/ui-kit/form-ui/src/form-api.ts

@@ -130,6 +130,11 @@ export class FormApi {
     return form.values;
   }
 
+  async isFieldValid(fieldName: string) {
+    const form = await this.getForm();
+    return form.isFieldValid(fieldName);
+  }
+
   merge(formApi: FormApi) {
     const chain = [this, formApi];
     const proxy = new Proxy(formApi, {
@@ -348,4 +353,14 @@ export class FormApi {
     }
     return await this.submitForm();
   }
+
+  async validateField(fieldName: string, opts?: Partial<ValidationOptions>) {
+    const form = await this.getForm();
+    const validateResult = await form.validateField(fieldName, opts);
+
+    if (Object.keys(validateResult?.errors ?? {}).length > 0) {
+      console.error('validate error', validateResult?.errors);
+    }
+    return validateResult;
+  }
 }