問題描述

我嘗試在 .ts 文件中設置間隔，但我不明白如何在間隔中使用同一文件中的函數.

I try to set an interval in a .ts file but I don't understand how to use a function in the same file in the interval.

解釋一下:

我的間隔設置:

this.task = setInterval(function () {
            this.refreshData();
        }, 300);

和我的函數在同一個 ts 文件中:

And my function in the same ts file :

refreshData() : void{
        console.log('update...');
    }

當我在我的設備上運行時，我遇到了這個錯誤:

When I run on my device, I have this error :

04-19 10:38:57.535 21374-21374/com.ionicframework.app722890 I/chromium: [INFO:CONSOLE(79432)] "TypeError: this.refreshData is not a function
                                                                                      at file:///android_asset/www/build/main.js:10987:18
                                                                                      at t.invokeTask (file:///android_asset/www/build/polyfills.js:3:10284)
                                                                                      at Object.onInvokeTask (file:///android_asset/www/build/main.js:39626:37)
                                                                                      at t.invokeTask (file:///android_asset/www/build/polyfills.js:3:10220)
                                                                                      at e.runTask (file:///android_asset/www/build/polyfills.js:3:7637)
                                                                                      at invoke (file:///android_asset/www/build/polyfills.js:3:11397)
                                                                                      at e.args.(anonymous function) (file:///android_asset/www/build/polyfills.js:2:30193)", source: file:///android_asset/www/build/main.js (79432)

我嘗試這種方式但我不工作:

I try this way but I doesn't work :

this.task = setInterval(this.refreshData(), 300);

這只會調用我的函數一次.

This call my function only one time.

有人有想法嗎?

推薦答案

使用箭頭函數

this.task = setInterval(() => {
  this.refreshData();
}, 300);

或像這樣存儲上下文

let self = this;
this.task = setInterval(function () {
  self.refreshData();
}, 300);

或使用綁定

this.task = setInterval((function () {
  this.refreshData();
}).bind(this), 300);

如果只有一個函數調用:

if only one function call:

this.task = setInterval(this.refreshData.bind(this), 300);

您可以通過 https://github.com/getify/You-Dont-Know-JS/tree/1st-ed/this%20%26%20object%20prototypes/ch1.md

這篇關于離子2:設置間隔的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！