在module.json5文件中配置abilities的supportWindowMode字段，用于指定窗口显示模式。
fullscreen表示支持全屏显示，split表示支持分屏显示，floating表示支持窗口化显示。
参考代码如下：
"abilities": [
{
"name": "EntryAbility",
"srcEntry": "./ets/entryability/EntryAbility.ets",
"description": "$string:EntryAbility_desc",
"icon": "$media:icon",
"label": "$string:EntryAbility_label",
"startWindowIcon": "$media:icon",
"startWindowBackground": "$color:start_window_background",
"exported": true,
"supportWindowMode": ["split", "floating"],
"skills": [
{
"entities": [
"entity.system.home"
],
"actions": [
"ohos.want.action.home"
]
}
]
}
], 参考链接