[英]Wait for Http Request complete before executing next line after subscribe in angular2
你能在評論中回答問題嗎
class TextComp
{
result: string;
constructor() {
this.getdata().subscribe(result => {
console.log("result received");
this.result = result;
});
console.log("called before result received " + this.result);
//this.result is NULL/UNDEFINED because this line executed before data received
// So how we can eliminate this situation??? or
// Is there any way to make synchronus call to http in angular 2
}
getdata() {
return http.get('test.json')
.map(response => response.json());
}
}
那么我們如何才能消除這種情況??? 或者有什么方法可以在angular 2中同步調用http
如果你需要在這種情況下進行同步調用,你的代碼應該是這樣的:
this.getdata().subscribe(result => {
console.log("result received");
this.result = result;
//function or snippet which will be called after subscribe is complete...
});
因為您的 subscribe 方法是異步工作的。 我建議你也看看promises 。
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.