时间戳

首页 > 解决方案 > 角度拖放 - 无法将项目拖放到目标位置

angular - 角度拖放 - 无法将项目拖放到目标位置

问题描述

我的 Angular 9 项目存在问题，其中拖放功能无法始终如一地工作。每当我尝试将对象拖动到其目标位置时，拖放都不会完成。大多数情况下，对象会返回到其原始位置，或者它会移动到我想要将对象移动到的目标位置之前或之后的另一个位置。这是我的代码：

<div class="col-sm-12">

          <div cdkDropList class="example-list cdk-drop-list-receiving" (cdkDropListDropped)="drop($event)">
            <ng-container *ngFor="let word of Words; let i = index;">
                <div class="row" *ngIf="((i % 2) == 0)"  style="margin-right: 0px; margin-left: 0px;" >
                  <div class="col-sm-1 text-center" style="padding: 20px 10px; border: 1px solid black"> {{ i }}</div>
                  <div class="col-sm-5 text-center example-box"  style="border: 1px solid black" cdkDrag ><div class="example-custom-placeholder" *cdkDragPlaceholder></div>{{ Words[i].Title }}</div>
                  <div class="col-sm-1 text-center" style="padding: 20px 10px; border: 1px solid black"> {{ i+1 }}</div>
                  <div class="col-sm-5 text-center example-box" *ngIf="Words[i+1] !== undefined" style="border: 1px solid black" cdkDrag ><div class="example-custom-placeholder" *cdkDragPlaceholder></div>{{ Words[i+1].Title }}</div>
                </div>

            </ng-container>
          </div> 
        </div>

这是应用程序的实时链接，因此您可以直观地看到我看到的问题：[更新] https://stackblitz.com/edit/drag-and-drop-issue

先感谢您

标签： angularangular-materialdrag-and-dropangular-cdk

解决方案

Cdk 下拉列表可以垂直或水平工作。在你的代码索引被搞砸了。你真正需要的是一个 CdkDropListGroup 让它双向运行。我已经为您的布局创建了一个相同的代码。我使同一个数组的行为类似于同一个 cdkDropListGroup 中的两个不同的 cdkdroplist。

工作 Stackblitz：- https://stackblitz.com/edit/drag-and-drop-issue-gw4epd

HTML

<div cdkDropListGroup class="row example-list cdk-drop-list-receiving">
    <div class="row">
        <div class="col-6 group" cdkDropList id="listOne" (cdkDropListDropped)="drop($event)" [cdkDropListConnectedTo]="['listTwo']">
            <ng-container *ngFor="let word of Words; let i=index">
                <div *ngIf="(i%2)==0" class="row" style="margin-right: 0px; margin-left: 0px;">
                    <div class="col-sm-2 text-center" style="padding: 20px 10px; border: 1px solid black"> {{ i }}
                    </div>
                    <div class="col-sm-10 text-center example-box" style="border: 1px solid black" cdkDrag>
                        <div class="example-custom-placeholder col-sm-10" *cdkDragPlaceholder></div>
                        {{ Words[i].Title }}
                    </div>
                </div>
            </ng-container>
        </div>
        <div class="col-6 group" cdkDropList id="listTwo" (cdkDropListDropped)="drop($event)" [cdkDropListConnectedTo]="['listOne']">
            <ng-container *ngFor="let word of Words; let i=index">
                <div *ngIf="(i%2)!==0" class="row" style="margin-right: 0px; margin-left: 0px;">
                    <div class="col-sm-2 text-center" style="padding: 20px 10px; border: 1px solid black"> {{ i }}
                    </div>
                    <div class="col-sm-10 text-center example-box" style="border: 1px solid black" cdkDrag>
                        <div class="example-custom-placeholder col-sm-10" *cdkDragPlaceholder></div>
                        {{ Words[i].Title }}
                    </div>
                </div>
            </ng-container>
        </div>
    </div>
</div>



<!-- Copyright 2019 Google LLC. All Rights Reserved.
    Use of this source code is governed by an MIT-style license that
    can be found in the LICENSE file at http://angular.io/license -->

TS：- 

import {Component} from '@angular/core';
import {CdkDragDrop, moveItemInArray} from '@angular/cdk/drag-drop';

/**
 * @title Drag&Drop custom placeholder
 */
@Component({
  selector: 'cdk-drag-drop-custom-placeholder-example',
  templateUrl: 'cdk-drag-drop-custom-placeholder-example.html',
  styleUrls: ['cdk-drag-drop-custom-placeholder-example.css'],
})
export class CdkDragDropCustomPlaceholderExample {
  Words = [
    {Title: 'Test A'},
    {Title: 'Test B'},
    {Title: 'Test C'},
    {Title: 'Test D'},
    {Title: 'Test E'},
    {Title: 'Test F'},
    {Title: 'Test G'},
    {Title: 'Test H'},
    {Title: 'Test I'},
    {Title: 'Test J'},
    {Title: 'Test K'},
    {Title: 'Test L'},
    {Title: 'Test M'},
    {Title: 'Test N'},
    {Title: 'Test O'}

  ];

  drop(event: CdkDragDrop<string[]>) {
    console.log(event);
    if (event.previousContainer === event.container) {
      console.log("same Container");
      if(event.previousContainer.id === 'listOne'){
        moveItemInArray(this.Words, event.previousIndex*2, event.currentIndex*2);
      } else {
        moveItemInArray(this.Words, (event.previousIndex*2)+1, (event.currentIndex*2)+1)
      }
    } else {
      console.log("different Container");
      var connectedTo = event.previousContainer.connectedTo.toString();
      console.log(connectedTo)
      if(connectedTo ==='listOne') {
        console.log('list2');
        moveItemInArray(this.Words, (event.previousIndex*2)+1, (event.currentIndex*2));
      } else {
        console.log('list1');
        moveItemInArray(this.Words, (event.previousIndex*2), (event.currentIndex*2)+1);
      }
    }
  }
}


/**  Copyright 2019 Google LLC. All Rights Reserved.
    Use of this source code is governed by an MIT-style license that
    can be found in the LICENSE file at http://angular.io/license */

CSS :- 

.example-list {
  width: 500px;
  max-width: 100%;
  border: solid 1px #ccc;
  min-height: 60px;
  display: block;
  background: white;
  border-radius: 4px;
  overflow: hidden;
}

.group{
  padding: 0;
  margin: 0;
}

.example-box {
  padding: 20px 10px;
  border-bottom: solid 1px #ccc;
  color: rgba(0, 0, 0, 0.87);
  display: flex;
  flex-direction: row;
  align-items: center;
  justify-content: space-between;
  box-sizing: border-box;
  cursor: move;
  background: white;
  font-size: 14px;
}

.cdk-drag-preview {
  box-sizing: border-box;
  border-radius: 4px;
  box-shadow: 0 5px 5px -3px rgba(0, 0, 0, 0.2),
              0 8px 10px 1px rgba(0, 0, 0, 0.14),
              0 3px 14px 2px rgba(0, 0, 0, 0.12);
}

.cdk-drag-animating {
  transition: transform 250ms cubic-bezier(0, 0, 0.2, 1);
}

.example-box:last-child {
  border: none;
}

.example-list.cdk-drop-list-dragging .example-box:not(.cdk-drag-placeholder) {
  transition: transform 250ms cubic-bezier(0, 0, 0.2, 1);
}

.example-custom-placeholder {
  background: #ccc;
  border: dotted 3px #999;
  min-height: 60px;
  transition: transform 250ms cubic-bezier(0, 0, 0.2, 1);
}

推荐阅读