ConstrainULong

ConstrainULong type is used to specify a constraint for a property whose value is an integral number. It extends the ULongRange dictionary (which provides the ability to specify a permitted range of property values) to also support an exact value and/or an ideal value the property should take on. In addition, you can specify the value as a simple long integer value, in which case the user agent does its best to match the value once all other more stringent constraints are met.

特性

If the value of a ConstrainULong is an object rather than a number, it may have the properties below in addition to the properties it inherits from ULongRange .

exact
An integer specifying precise, required, value the property must have to be considered acceptable.
ideal
An integer specifying a value the property would ideally have, but which can be considered optional if necessary to find a match.

规范

规范 状态 Comment
媒体捕获和流
The definition of 'ConstrainULong' in that specification.
候选推荐 初始定义

Technically, ConstrainULong is actually based on an intermediary dictionary named ConstrainULongRange , which adds exact and ideal to ULongRange , with ConstrainULong being a type that can be either a long integer or a ULongRange . However, for the sake of documentation clarity, the intermediate type (present only because of quirks in WebIDL syntax) is ignored here.

浏览器兼容性

更新 GitHub 上的兼容性数据
Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari Android webview Chrome for Android Firefox for Android Opera for Android Safari on iOS Samsung Internet
ConstrainULong Chrome No Edge No Firefox No IE No Opera No Safari No WebView Android No Chrome Android No Firefox Android No Opera Android No Safari iOS No Samsung Internet Android No

图例

不支持
不支持

另请参阅