我想从下拉列表中选择第一个选项。但是,当我设置 [attr.selected]="index == 1"
或 [attr.selected]="index == 0"
它不起作用,但如果我将索引值条件更改为 [attr.selected]="index == 2"
,就可以了。尽管存在从 0 到 2 的索引。
<select formControlName="segmentforOverlapOne" class="form-control overlap-segment-1">
<option [attr.selected]="index == 1" *ngFor="let segment of segmentations; let index=index;" [ngValue]="index">{{segment.name}}</option>
</select>
下面是分段数组:
[
{
"name": "name 1",
"columns": [
{
"index": 0,
...
}
],
},
{
"name": "name 2",
"columns": [
{
"index": 1,
...
}
],
},
{
"name": "name 3",
"columns": [
{
"index": 2,
...
}
]
}
]
最佳答案
像这样尝试:
<select formControlName="segmentforOverlapOne" class="form-control overlap-segment-1">
<option *ngFor="let segment of segmentations; let i = index" [attr.value]="i" [attr.selected]="i == 0 ? true : null">{{segment.name}}</option>
</select>
关于Angular 默认选项选择的属性未按预期工作,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/47550394/