Angular/Ionic4输入框获焦键盘不弹出：Android需二次点击、iOS无响应

Hey there, let's work through this keyboard pop-up issue you're hitting with Ionic 4 and Angular—since you're new to the stack, I'll break this down step by step so it's easy to follow!

First, let's spot a quick typo in your code that might be causing part of the problem:
Your <ion-input> has type="input" which isn't a valid input type. For text entry, you should use type="text" instead. That small mistake could throw off how the mobile OS recognizes the input field and triggers the keyboard. Here's the corrected snippet for that part:

<ion-input 
  type="text" 
  placeholder="Enter your first name" 
  [readonly]="isReadOnly" 
  name="profile" 
  [value]="firstName" 
  #nameCtrl="ngModel" 
  ngModel 
  pattern="[A-Za-z]+" 
  minlength="3" 
  maxlength="20" 
  [(ngModel)]="firstName" 
  #name 
  no-padding>
</ion-input>

Next, even though you tried the Cordova Keyboard plugin, let's make sure it's set up properly—sometimes small configuration gaps can make it seem like it's not working:

1. Double-check you have both the plugin and the Ionic Native wrapper installed:

   ionic cordova plugin add cordova-plugin-ionic-keyboard
   npm install @ionic-native/keyboard
   

2. Add the Keyboard service to your app.module.ts providers so it's available across your app:

   import { Keyboard } from '@ionic-native/keyboard/ngx';
   
   @NgModule({
     // ... other imports and declarations
     providers: [
       // ... other providers
       Keyboard
     ]
   })
   export class AppModule {}
   

3. In your component, add code to force the keyboard to show when the input is focused. Sometimes the native focus event doesn't trigger reliably, so a little nudge helps:

   import { Component, ViewChild, ElementRef } from '@angular/core';
   import { Keyboard } from '@ionic-native/keyboard/ngx';
   
   @Component({
     selector: 'app-your-component',
     templateUrl: './your-component.page.html',
     styleUrls: ['./your-component.page.scss'],
   })
   export class YourComponentPage {
     @ViewChild('name') nameInput: ElementRef;
     firstName: string = '';
     isReadOnly: boolean = false; // Make sure this starts as false—if it's true initially, the input is locked!
   
     constructor(private keyboard: Keyboard) {}
   
     onInputFocus() {
       // Add a small delay to make sure the focus registers before calling the keyboard
       setTimeout(() => {
         this.nameInput.nativeElement.focus();
         this.keyboard.show();
       }, 100);
     }
   }
   

   Then bind this function to the input's ionFocus event in your template:

   <ion-input 
     <!-- ... all your existing attributes -->
     (ionFocus)="onInputFocus()"
     #name 
     no-padding>
   </ion-input>
   

For iOS specifically, there's a default setting that blocks automatic keyboard pop-ups unless the user explicitly taps. Fix that by adding these preferences to your config.xml:

<preference name="KeyboardDisplayRequiresUserAction" value="false" />
<preference name="DisallowOverscroll" value="true" />

This tells iOS it's okay to show the keyboard when the input is focused, without an extra tap.

Also, double-check your isReadOnly variable—if it's set to true when the page loads, the input will be uneditable, so tapping it won't bring up the keyboard. Make sure it starts as false and only gets toggled to true when you actually need to lock the input.

Finally, a quick testing tip: Always test on a real device or official simulator (not just the browser) because keyboard behavior is very different in web vs native contexts. If you're still having issues, try removing and re-adding the platform to clear any cached build files:

# For Android
ionic cordova platform remove android && ionic cordova platform add android

# For iOS
ionic cordova platform remove ios && ionic cordova platform add ios

That should cover all the common causes for this keyboard issue. Give these steps a try and let me know if you run into any snags!

内容的提问来源于stack exchange，提问作者user8617560