当我输入文字来搜索某些内容时,在文本中显示一个字符非常慢。
问题是什么 ?
我显示了50个产品ngFor
如下所示,如果我显示超过50个产品100或150输入文字更慢。
我该怎么做才能解决这个问题?
<div class="width_products products-animation " *ngFor="let product of productsService.products ; trackBy: $index" [ngClass]="{ 'width_products_open_menu':productsService.status_menu }" >
<span class="each_width_product" >
<div class="title_products more_detail_product" (click)="set_router({ path:product['company'].company_name+'/'+product.product_title , data:product.product_id , relative:true })">
{{product.product_title }}
<span class="glyphicon glyphicon-chevron-down"></span><br>
<div class=' glyphicon glyphicon-time'></div> {{product.product_date}}
</div>
<div class="image_product_primary " (click)="set_router({ path:product['company'].company_name+'/'+product.product_title , data:product.product_id , relative:true })">
<img class="image_product" src="../../assets/images/products_image/{{product.product_image}}">
</div>
<button (click)="product.product_in_wishList='true'; productsService.add_wish_list( product )" mat-button class="wish_list notCloseDropdawnFavorite notCloseDropdawnCard">
<span class="write_add_wish">{{dataservices.language.add_wishlist}}</span>
<mat-icon *ngIf="product.product_in_wishList == 'false' " class="notCloseDropdawnFavorite notCloseDropdawnCard">favorite_border</mat-icon>
<mat-icon *ngIf="product.product_in_wishList == 'true' " class="hearts_div_hover notCloseDropdawnFavorite notCloseDropdawnCard">favorite</mat-icon>
</button>
<div class="footer_products">
<span matTooltip="Views!">
<div class="button_footer_products">
<span class="glyphicon glyphicon-eye-open icon_eye"></span>
<div class="both_write ">
12889
</div>
</div>
</span>
<span matTooltip="Add to your card" class="notCloseDropdawnCard notCloseDropdawnFavorite " (click)="product.product_in_cartList='true'; productsService.add_cart_list( product )">
<div class="button_footer_products">
<span *ngIf="product.product_in_cartList=='false'" class="glyphicon glyphicon-plus icon_eye notCloseDropdawnCard notCloseDropdawnFavorite" ></span>
<span *ngIf="product.product_in_cartList=='true'" class="glyphicon glyphicon-ok icon_eye notCloseDropdawnCard notCloseDropdawnFavorite" ></span>
<div class="both_write ">
Cart
</div>
</div>
</span>
<span matTooltip="See Details!">
<div (click)="set_router({ path:product['company'].company_name+'/'+product.product_title , data:product.product_id , relative:true })" class="button_footer_products" >
<span class=" glyphicon glyphicon-option-horizontal icon_eye"></span>
<div class="both_write ">
More
</div>
</div>
</span>
</div>
<div class="prise_products">
Price:<del>$2500</del> $3500
</div>
<div class="plus_height"></div>
</span>
</div>
在标题组件中,我有一个输入类型文本,如下所示:
<input type="text" class="kerkim" name="search" [(ngModel)]="typing_search" placeholder="
{{dataservices.language.searchproducts}}">
答案 0 :(得分:1)
Debouce效果,例如不要立即进行搜索。
class Coponent {
private _timeoutId: number;
//to be called on search text changed
search(){
clearTimeout(this._timeoutId);
this._timeoutId = setTimeout(() => {
//do search stuff
}, 500) //play with delay
}
}
使用搜索关键字缓存prev结果。 当kyeword改变如此[&#34; k&#34;,&#34; ke&#34;,&#34; key&#34;]时,您不需要重新整理整个数组。
class Search {
private _keywordChanges:string[] = [];
private _prevFilterResults: any[] = [];
private _allData: any[] = [];
search(keyword:string){
let prevKeyword = this.getPrevKeyword(),
toBeFiltered: any[];
if(keyword.match(keyword)){ //if it was "ke" and now it is "key"
//filter prev results only
toBeFiltered = this._prevFilterResults;
} else {
//filter prev results or even make cache for keyword
toBeFiltered = this._allData;
}
let results = toBeFiltered.filter(() => {});
this._prevFilterResults = results;
}
private getPrevKeyword(){
return this._keywordChanges[this._keywordChanges.length - 1];
}
使用for而不是Array.filter(),在某些情况下它可能会有所帮助。例如,你已经排序数组[&#34; a&#34;,&#34; apple&#34;,&#34; b&#34;,&#34; banana&#34;]和关键字&#34; a& #34;
function search(array:any[], keyword:string) {
//so
let results = [];
for(let i = 0; i < array.length; i++){
let item = array[i];
if(item.toString().startsWith(keyword)){
results.push(item);
} else {
break; //as b and banana left
}
}
return results;
}
看一下二进制搜索。 How to implement binary search in JavaScript 和哈希表Hash table runtime complexity (insert, search and delete)
答案 1 :(得分:0)
从我的问题开始:由于许多数据,每个输入字段都很慢。因此我在重新加载数据的位置添加了“ changeDetection:ChangeDetectionStrategy.OnPush”,然后一切正常。
@Component({
selector: 'app-app-item',
templateUrl: './app-item.component.html',
styleUrls: ['./app-item.component.css'],
changeDetection: ChangeDetectionStrategy.OnPush,
})