angular - registerBackButtonAction , Ionic2 , 针对不同的页面

Question

我正在开发 Ionic2 应用程序。我对 registerBackButtonAction 功能感到困惑。

我已经在一个页面上完成了这个(比如 pageA)。并且它按预期工作。

this.platform.registerBackButtonAction(() => {
     console.log("back presed");
    this.abortDownloadAndExit();
    });

现在我想对其他页面 (sayPageB) 上的 registerBackButtonAction 执行一些其他操作。但是 Ionic 正在从 pageA

采取行动

如何在不同的页面上注册不同的 Action 。

Answer 1

正如您在 Ionic docs 中看到的那样registerBackButtonAction 返回一个函数:

A function that, when called, will unregister its back button action. So you can use that function to restore the default behavior when leaving the page, like this:

import { Component} from '@angular/core';

@Component({
    selector: 'page-home',
    templateUrl: 'home.html'
})
export class HomePage {

    // Property used to store the callback of the event handler to unsubscribe to it when leaving this page
    public unregisterBackButtonAction: any;

    constructor(...) { ... }

    ionViewDidEnter() {
        this.initializeBackButtonCustomHandler();
    }

    ionViewWillLeave() {
        // Unregister the custom back button action for this page
        this.unregisterBackButtonAction && this.unregisterBackButtonAction();
    }

    public initializeBackButtonCustomHandler(): void {
        this.unregisterBackButtonAction = this.platform.registerBackButtonAction(() => {
            this.customHandleBackButton();
        }, 10);
    }

    private customHandleBackButton(): void {
        // do what you need to do here ...
    }
}

因此如您所见，关键是要存储 registerBackButtonAction 方法的回调，以便稍后在离开页面时(或当您想恢复默认行为时)使用它:

this.unregisterBackButtonAction = this.platform.registerBackButtonAction(() => {
    this.customHandleBackButton();
}, 10);