If ngModel is used within a form tag, either the name attribute must be set or the form
control must be defined as ‘standalone’ in ngModelOptions.

0.背景

angular项目，用的NG-ZORRO

一个简单的表单提交页面，本来不想用form，直接写的row和col。但是页面太丑了，加上form吧，开始报错（其实就是不熟练）。

1.报错原因及解决方法

我的当时的非主流代码如下：

  <form nz-form>
    <nz-row>
        <nz-col nzSpan="12">
            <nz-form-item>
                <nz-form-label [nzSm]="6" [nzXs]="24" nzFor="region">地区</nz-form-label>
                <nz-form-control [nzSm]="18" [nzXs]="24">
                    <input nz-input [(ngModel)]="tableData.region" formControlName="region"
                        placeholder="地区" id="region"/>
                </nz-form-control>
            </nz-form-item>
        </nz-col>
        <nz-col nzSpan="12">
            <nz-form-item>
                <nz-form-label [nzSm]="6" [nzXs]="24" nzFor="lawCode">项目名称</nz-form-label>
                <nz-form-control [nzSm]="18" [nzXs]="24">
                    <input nz-input [(ngModel)]="tableData.lawCode" formControlName="lawCode"
                        placeholder="项目名称" id="lawCode"/>
                </nz-form-control>
            </nz-form-item>
        </nz-col>
    </nz-row>
</form>

一开始直接用的input，后来觉得不好看，改成form后，开始报下面的错：

formControlName must be used with a parent formGroup directive.  You'll want to add a formGroup
       directive and pass it an existing FormGroup instance (you can create one in your class).

我想了想我这个非主流代码，于是就把formControlName给删除了，结果报错：

If ngModel is used within a form tag, either the name attribute must be set or the form<br>control must be defined as 'standalone' in ngModelOptions.

大概的意思是，如果你要在form中使用ngModel，必须定义stanalone。好吧，终于根据提示加上了代码。

  <form nz-form>
    <nz-row>
        <nz-col nzSpan="12">
            <nz-form-item>
                <nz-form-label [nzSm]="6" [nzXs]="24" nzFor="region">地区</nz-form-label>
                <nz-form-control [nzSm]="18" [nzXs]="24">
                    <input nz-input [(ngModel)]="tableData.region" [ngModelOptions]="{standalone: true}" 
                        placeholder="地区" id="region"/>
                </nz-form-control>
            </nz-form-item>
        </nz-col>
        <nz-col nzSpan="12">
            <nz-form-item>
                <nz-form-label [nzSm]="6" [nzXs]="24" nzFor="lawCode">项目名称</nz-form-label>
                <nz-form-control [nzSm]="18" [nzXs]="24">
                    <input nz-input [(ngModel)]="tableData.lawCode" [ngModelOptions]="{standalone: true}" 
                        placeholder="项目名称" id="lawCode"/>
                </nz-form-control>
            </nz-form-item>
        </nz-col>
    </nz-row>
</form>

这样表单就好看多了。