angular基于ng-alain定义自己的select组件示例

1、首先是my-select2.component.html页面,这里是在ng-alain的select基础上根据业务需求添加新的功能;代码如下：

<nz-select #select style="width:100%;" [(ngModel)]="selectedOption" [nzPlaceHolder]="myPlaceHolder" nzAllowClear [nzShowSearch]="true" [nzNotFoundContent]="'无匹配'">
<nz-option
*ngFor="let option of options"
[nzLabel]="option.label"
[nzValue]="option"
[nzDisabled]="option.disabled">
</nz-option>
</nz-select>

2、再者是my-select2.component.ts页面,代码里面有注释;代码如下：

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 $: any;
@Component({
selector: 'nz-select2',
templateUrl: './my-select2.component.html',
providers: [
{
provide: NG_VALUE_ACCESSOR,
useExisting: forwardRef(() => NzSelect2Component),//注入表单控件
multi: true
}]
})
export class NzSelect2Component implements OnInit{
constructor(private selectService:SelectService) {
}
innerValue: any = '';
//监听绑定的值，与外岑的ngModel相互绑定
set selectedOption(val:any){
if (val !== this.innerValue) {
this.innerValue = val;
this.onChangeCallback(val.value);
this.dataBack.emit(val.value); // 事件
}
}
get selectedOption():any{
return this.innerValue;
}
options = [];//接收select的数组
_dataSource:any;//接收本地的自定义数组或者请求返回的数组
@Input()
url:any;//请求的url
@Input()
myPlaceHolder:any;//自定义的PlaceHolder
@Input()
//下拉框的数据格式
fieldKey:any = {
text: 'text',
value: 'value'
};
@Input()
set dataSource(val: any) {
this._dataSource = val;
if ($.isArray(this._dataSource)) {
this.options=this._dataTransform(this._dataSource);//如果是本地数组或直接请求的数组直接复制
}
}
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存在则直接请求
if(this.url){
this.selectService.getValue(this.url).subscribe(data => {
data = data.rows || data.data;
this.options=this._dataTransform(data);
});
}
}
//转换下拉框下的字段
_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;
}
}

3、然后是my-select2.service.ts页面,这里主要是请求后台接口返回的下拉数组，url为父组件传过来的链接,代码如下：

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);
}
}

4、然后是myselect.module.ts页面,这里，使用该组件的前提是要引入 import { NzSelectModule } from 'ng-zorro-antd',代码如下：

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() {
}
}

5、使用方法,在你需要的模块引入：MySelectModule

import { MySelectModule } from 'bizapp/base/components/myselect/myselect.module';

6、如何调用：url为请求后台的接口，fieldKey为数组的格式，这里可以根据后台返回来的格式定义这里的字段，如：后台返回格式为[{dmsm1:5,dmz:5}]则fieldKey的定义如下，myPlaceHolder为初始化时显示的内容，如果是本地数组，则只需要加上[dataSource]="peer"，这里的peer为本地数组

• [url=https://www.geek-share.com/detail/2745728894.html]Angular6 写一个简单的Select组件示例" target=_blank>="'analysis/api/data/code/list/030107'" [(ngModel)]="search2.hpzl" [fieldKey]="{text:'dmsm1',value:'dmz'}" [myPlaceHolder]="'号牌种类'"></nz-select2>
  

  7、总结：通过这个组件，我们只需要修改url和fieldKey就可以在任意模块引入然后使用，减少代码的使用，方便维护

  以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。

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