仅当集合在 flutter 中有文档时，如何使小部件可见？
[英]How do i make a widget visible only if the collection has docs in flutter?
问题描述
I'm using firebase database and i want to show a certain widget if there was docs only.
我正在使用 firebase 数据库，如果只有文档，我想显示某个小部件。 i tried this line but it's not the right one.我试过这条线，但它不是正确的。
Visibility(
visible: controller.doc.isEmpty(),
2 个解决方案
解决方案1
1 2022-09-15 00:52:41
Not sure what controller.doc.isEmpty() does but you want the widget to be visible if the doc is not empty.不确定controller.doc.isEmpty()做了什么，但如果文档不为空，您希望小部件可见。 So you have to change it to:因此，您必须将其更改为：
Visibility(
visible: !controller.doc.isEmpty(),
)
解决方案2
0 2022-09-15 05:55:50
Try the following code:试试下面的代码：
Visibility(
visible: controller.doc.isNotEmpty(),
),
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