url QML Basic Type

The url type refers to a resource locator (like a file name, for example). It can be either absolute, e.g. "http://qt-project.org", or relative, e.g. "pics/logo.png". A relative URL is resolved relative to the URL of the containing component.

For example, the following assigns a valid URL to the Image::source property, which is of type url :

Image { source: "pics/logo.png" }

When integrating with C++, note that any QUrl 值 passed into QML from C++ is automatically converted into a url value, and vice-versa.

Using the url Type

When a relative URL is written to a url type property, it is converted into a URL object, so matching the URL value against the input string value will fail . Instead, convert the string to a URL using Qt.resolvedUrl() for means of comparison, and use toString() to get the contents of the URL:

Image {
    source: "pics/logo.png"
    Component.onCompleted: {
        // This prints 'false'. Although "pics/logo.png" was the input string,
        // it's been converted from a string to a URL, so these two are not the same.
        console.log(source == "pics/logo.png")
        // This prints 'true' as Qt.resovledUrl() converts the string into a
        // URL with the correctly resolved path
        console.log(source == Qt.resolvedUrl("pics/logo.png"))
        // This prints the absolute path, e.g. "file:///path/to/pics/logo.png"
        console.log(source.toString())
    }
}

注意： When referring to files stored with the Qt 资源系统 from within QML, you should use "qrc:///" instead of ":/" as QML requires URL paths. Relative URLs resolved from within that file will use the same protocol.

Additionally, URLs may contain encoded characters using the 'percent-encoding' scheme specified by RFC 3986 . These characters will be preserved within properties of type url , to allow QML code to construct precise URL values. An exception to this rule is the preemptive decoding of directory-separator characters ( '/' ) - these characters are decoded to allow the URL to be correctly classified.

For example, a local file containing a '#' character, which would normally be interpreted as the beginning of the URL 'fragment' element, can be accessed by encoding the characters of the file name:

Image { source: encodeURIComponent("/tmp/test#1.png") }

此基本类型由 QML 语言提供。

另请参阅 QML 基本类型 .