1、首先是my-select2.component.html頁面,這裡是在ng-alain的select基礎上根據業務需求新增新的功能;程式碼如下：
<nz-select #select style="width:100%;" [(ngModel)]="selectedOption" [nzPlaceHolder]="myPlaceHolder" nzAllowClear [nzShowSearch]="true" [nzNotFoundContent]="'無匹配'">
<nz-option
*ngFor="let option of options"
[nzLabel]="option.label"
[nzValue]="option"
[nzDisabled]="option.disabled">
</nz-option>
</nz-select>
複製程式碼2、再者是my-select2.component.ts頁面,程式碼裡面有註釋;程式碼如下：
import { ControlValueAccessor } from '@angular/forms/src/directives';
import { Component, forwardRef, Input,OnInit,ElementRef,Output,EventEmitter} from '@angular/core';
import { NG_VALUE_ACCESSOR } from '@angular/forms';
import { Router, NavigationEnd } from '@angular/router';
import { FormGroup, FormBuilder, Validators } from '@angular/forms';
import { SelectService } from './my-select2.service';
declare var $: any;
@Component({
selector: 'nz-select2',
templateUrl: './my-select2.component.html',
providers: [
{
provide: NG_VALUE_ACCESSOR,
useExisting: forwardRef(() => NzSelect2Component),//注入表單控制元件
multi: true
}]
})
export class NzSelect2Component implements OnInit{
constructor(private selectService:SelectService) {
}
innerValue: any = '';
//監聽繫結的值，與外岑的ngModel相互繫結
set selectedOption(val:any){
if (val !== this.innerValue) {
this.innerValue = val;
this.onChangeCallback(val.value);
this.dataBack.emit(val.value); // 事件
}
}
get selectedOption():any{
return this.innerValue;
}
options = [];//接收select的陣列
_dataSource:any;//接收本地的自定義陣列或者請求返回的陣列
@Input()
url:any;//請求的url
@Input()
myPlaceHolder:any;//自定義的PlaceHolder
@Input()
//下拉框的資料格式
fieldKey:any = {
text: 'text',
value: 'value'
};
@Input()
set dataSource(val: any) {
this._dataSource = val;
if ($.isArray(this._dataSource)) {
this.options=this._dataTransform(this._dataSource);//如果是本地陣列或直接請求的陣列直接複製
}
}
get dataSource(): any {
return this._dataSource;
}
@Output() dataBack = new EventEmitter<any>();
registerOnChange(fn: (value: any) => void) {
this.onChangeCallback = fn;
}
registerOnTouched(fn: any) {
this.onTouchedCallback = fn;
}
writeValue(value: string) {
}
onChangeCallback = (value: any) => {};
onTouchedCallback = (value: any) => {};
ngOnInit() {
//如果url存在則直接請求
if(this.url){
this.selectService.getValue(this.url).subscribe(data => {
data = data.rows || data.data;
this.options=this._dataTransform(data);
});
}
}
//轉換下拉框下的欄位
_dataTransform(data: Array<any>){
let _data = [];
for (let i = 0; i < data.length; i++) {
_data[i] = {};
_data[i].label = data[i][this.fieldKey.text];
_data[i].value = data[i][this.fieldKey.value];
}
return _data;
}
}
複製程式碼3、然後是my-select2.service.ts頁面,這裡主要是請求後臺介面返回的下拉陣列，url為父元件傳過來的連結,程式碼如下：
import { Injectable } from '@angular/core';
import { Headers, Http, URLSearchParams,RequestOptions } from '@angular/http';
import { HttpClient, HttpErrorResponse } from '@angular/common/http';
import 'rxjs/add/operator/toPromise';
// import { environment } from '../../environments/environment';
@Injectable()
export class SelectService {
constructor(private http: HttpClient) {}
getValue(url: any):any{
return this.http
.get(url);
}
}
複製程式碼4、然後是myselect.module.ts頁面,這裡，使用該元件的前提是要引入 import { NzSelectModule } from 'ng-zorro-antd',程式碼如下：
import { NgModule, ModuleWithProviders } from '@angular/core';
import { CommonModule } from '@angular/common';
import { FormsModule,ReactiveFormsModule } from '@angular/forms';
import { NzSelect2Component } from './my-select2.component';
import { SelectService } from './my-select2.service';
import { NzSelectModule } from 'ng-zorro-antd';
@NgModule({
imports: [
CommonModule,
FormsModule,
NzSelectModule,
ReactiveFormsModule
],
exports:[
NzSelect2Component
],
declarations: [
NzSelect2Component
],
providers: [
SelectService
]
})
export class MySelectModule {
constructor() {
}
}
複製程式碼5、使用方法,在你需要的模組引入：MySelectModule
import { MySelectModule } from 'bizapp/base/components/myselect/myselect.module';
複製程式碼6、如何呼叫：url為請求後臺的介面，fieldKey為陣列的格式，這裡可以根據後臺返回來的格式定義這裡的欄位，如：後臺返回格式為[{dmsm1:5,dmz:5}]則fieldKey的定義如下，myPlaceHolder為初始化時顯示的內容，如果是本地陣列，則只需要加上[dataSource]="peer"，這裡的peer為本地陣列
<nz-select2 [url]="'analysis/api/data/code/list/030107'" [(ngModel)]="search2.hpzl" [fieldKey]="{text:'dmsm1',value:'dmz'}" [myPlaceHolder]="'號牌種類'"></nz-select2>
複製程式碼7、總結：通過這個元件，我們只需要修改url和fieldKey就可以在任意模組引入然後使用，減少程式碼的使用，方便維護