Question

我正在Angular做我的第一个项目，我不知道该怎么做，我一直在搜索，但是我没有找到我想要的东西。

下一个结构。主页->教程页面->登录页面

当您进入LoginPage并提供虚拟的后退或后退按钮时，该按钮实际上显示在左侧上方，我要返回的是HomePage。我一直在尝试不同的方法，但对我没有任何帮助，我的问题是，我不知道在按下时如何进行事件调用。谢谢

我的登录名

import { Component, OnInit } from '@angular/core';
import { IonicPage, NavController, NavParams, Platform } from 'ionic-angular';

@IonicPage()
@Component({
  selector: 'page-login',
  templateUrl: 'login.html',
})
export class LoginPage implements OnInit {

  constructor(public navCtrl: NavController, public navParams: NavParams, private platform: Platform) {
  }

  ngOnInit() {
    this.platform.backButton.subscribe(() => {
      this.navCtrl.popToRoot();
    });
  }

  goToSignUp() {
    let id = this.idRecibido;
    this.navCtrl.push("SignupPage", {id});
  }

}

我还需要它与屏幕上的虚拟按钮配合使用

Answer 1

您需要注入Platform服务并订阅其backButton这样的Observable：

import { Component, OnInit } from '@angular/core';
import { IonicPage, NavController, NavParams } from 'ionic-angular';

@IonicPage()
@Component({
  selector: 'page-login',
  templateUrl: 'login.html',
})
export class LoginPage implements OnInit {

  constructor(public navCtrl: NavController, public navParams: NavParams, private platform: Platform) {
  }

  ngOnInit() {
    this.platform.backButton.subscribe(() => {
      // Physical button pressed
    });
  }

  goToSignUp() {
    this.navCtrl.push("SignupPage");
  }

}

Answer 2

我的问题的完美解决方案是这个。

def merge(l1, l2):
    first = ListNode(0)
    # 'here' is where we link in the nodes.
    here = first
    while l1 and l2:
        # Pick the next node from the inputs.
        # Note that this has the same effect as assigning
        # to 'first.next' on the first iteration, when 'first' and 'here'
        # refer to the same object.
        if l1.val < l2.val:
            here.next = l1
        else:
            here.next = l2
        # Move along to the last node we picked.
        here = here.next
    # Grab the rest.
    if l1:
        here.next = l1
    else:
        here.next = l2
    return first.next

在ionic 4中返回堆栈时出现问题

2 个答案: