Question

我的应用程序中有一个列表，它使用* ngFor显示在表格中。此列表一次可以在页面上显示10,50或100个项目。我希望用户能够控制表中显示的项目数量，因此我创建了一个Pipe指令，该指令传递由下拉输入控制的值：

   <select class="form-control" [(ngModel)]="aIndex">
       <option id="10" value="10" selected="selected">10</option>
       <option id="50" value="50">50</option>
       <option id="100" value="100">100</option>
   </select>

  <table>
    <tbody>
      <tr *ngFor="let item of aList | aIndexPipe: 'aIndex'>
        ...
       </tr>
    </tbody>
  </table>

我的管道代码如下：

import {Component, Inject, OnInit, Pipe, PipeTransform} from '@angular/core';

@Pipe({
  name: "aIndexPipe"
})

export class AIndexPipe implements PipeTransform {
  transform(array: Array<any>, arg1:any): Array<string> {

    var newArray =[];
    for(let i=0;i<arg1;i++) {
      newArray.push(array[i]);
    }
    return newArray;
  }
}

无论我选择什么，列表总是被转换为空。我错误地传递了这些论点吗？每当我将新值传递给ngModel变量时，是否必须调用更新函数？

Answer 1

解决了！将strSQL = "UPDATE [csd_dis_" & i_year & "_all] as d INNER JOIN [adm_" & a_yyyy & "] as aa ON d.d_cino = aa.a_cino and cstr(d.d_sentdte) = cstr(aa.a_sentdte) and right('00' + trim(str(d.m_d_nature)),2) = left(trim(cstr(aa.m_a_nature)),2) " strSQL = strSQL & "SET d.match_adm = " & kk & ",d.a_local_p = aa.a_local_p,d.inst = aa.c_inst, d.dosy = aa.dosy,d.dosm = aa.dosm,d.dosd = aa.dosd, " _ & "d.a_sentdte = aa.a_sentdte,d.tid = aa.tid,d.crb = aa.crb,d.crbchk = aa.crbchk, d.court = aa.court,d.ccn = aa.ccn,d.cyr = aa.cyr,d.a_nature = aa.nature,d.nature_o = aa.nature_o, " _ & "d.m_a_nature = aa.m_a_nature,d.class = aa.class,d.cat = aa.cat,d.ilossp = aa.ilossp,d.chap = aa.chap,d.sect = aa.sect,d.newoff = aa.newoff,d.hkid = aa.hkid,d.sex = aa.sex,d.doby = aa.doby,d.dobm = aa.dobm, " _ & "d.dobd = aa.dobd,d.a_dob = aa.a_dob,d.a_dob_imp = aa.a_dob_imp,d.age = aa.age,d.accom = aa.accom,d.disres = aa.disres,d.yrres = aa.yrres,d.edu = aa.edu,d.marst = aa.marst,d.bplbir = aa.bplbir,d.plbir = aa.plbir,d.yrhk = aa.yrhk, " _ & "d.[on] = aa.[on],d.sently = aa.sently,d.sentlm = aa.sentlm,d.sentld = aa.sentld,d.tr = aa.tr,d.dr = aa.dr,d.mr = aa.mr,d.inr = aa.inr,d.pvdg = aa.pvdg, d.pvndg = aa.pvndg,d.pvcn = aa.pvcn,d.pvcn2 = aa.pvcn2,d.bghome = aa.bghome, " _ & "d.pvdc = aa.pvdc,d.pvtc = aa.pvtc,d.pvdatc = aa.pvdatc,d.pvrc = aa.pvrc,d.pvpri = aa.pvpri,d.pvinst = aa.pvinst,d.foffen = aa.foffen,d.dfcy = aa.dfcy,d.dfcm = aa.dfcm,d.dfcd = aa.dfcd,d.a_dfcdte = aa.a_dfcdte, " _ & "d.agefcn = aa.agefcn,d.trisoc = aa.trisoc,d.ddpur = aa.ddpur,d.dcost = aa.dcost,d.cumd = aa.cumd,d.needle = aa.needle,d.yrdg = aa.yrdg,d.causa = aa.causa,d.fdg = aa.fdg,d.fmd = aa.fmd,d.agefdg = aa.agefdg, " _ & "d.yradd = aa.yradd,d.asso = aa.asso,d.la = aa.la,d.origin = aa.origin,d.mode = aa.mode,d.arrest = aa.arrest,d.stayy = aa.stayy,d.staym = aa.staym,d.stayd = aa.stayd,d.occ = aa.occ,d.name = aa.name,d.cname = aa.cname," _ & "d.othdocno = aa.othdocno,d.cudg1 = aa.cudg1,d.cudg2 = aa.cudg2,d.cudg3 = aa.cudg3,d.cudg4 = aa.cudg4,d.psydrug1 = aa.psydrug1,d.psydrug2 = aa.psydrug2,d.psydrug3 = aa.psydrug3, " _ & "d.psydrug4 = aa.psydrug4,d.agefpsy = aa.agefpsy,d.psydgfreq = aa.psydgfreq,d.psycausa = aa.psycausa WHERE '" & matchkey & "' and d.match_adm=' '"设为aIndexPipe: 'aIndex'，不要将在线教程发送到T。

Angular Pipe无法使用参数

1 个答案: