Question

我正在尝试使用SwiftGtk帮助将Gtk绑定到Swift。但是，在为HeaderBar添加类时，我收到错误：

/home/luis/Dropbox/Documentos/Coding/Swift/SwiftGtk/.build/checkouts/SwiftGtk--2571330441700638662/Sources/HeaderBar.swift:15:63: error: value of type 'UnsafePointer<gchar>' (aka 'UnsafePointer<Int8>') has no member 'toString'
        get { return gtk_header_bar_get_title(castedPointer())?.toString() }
                     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^ ~~~~~~~~
/home/luis/Dropbox/Documentos/Coding/Swift/SwiftGtk/.build/checkouts/SwiftGtk--2571330441700638662/Sources/HeaderBar.swift:20:66: error: value of type 'UnsafePointer<gchar>' (aka 'UnsafePointer<Int8>') has no member 'toString'
        get { return gtk_header_bar_get_subtitle(castedPointer())?.toString() }
                     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^ ~~~~~~~~
/home/luis/Dropbox/Documentos/Coding/Swift/SwiftGtk/.build/checkouts/SwiftGtk--2571330441700638662/Sources/HeaderBar.swift:41:75: error: value of type 'UnsafePointer<gchar>' (aka 'UnsafePointer<Int8>') has no member 'toString'
        get { return gtk_header_bar_get_decoration_layout(castedPointer())?.toString() }

似乎正在发生的事情是Gtk.HeaderBar get_title（）方法返回gchar，这是（我认为）类型UnsafePointer，它没有在代码中正确地转换为字符串：

public var title: String? {
    get { return gtk_header_bar_get_title(castedPointer())?.toString() }
    set { gtk_header_bar_set_title(castedPointer(), newValue) }
}

public var subtitle: String? {
    get { return gtk_header_bar_get_subtitle(castedPointer())?.toString() }
    set { gtk_header_bar_set_subtitle(castedPointer(), newValue) }
}

我应该遵循哪种方法将其转换为String？

Answer 1

从String获取UnsafePointer<Int8>有多种方法。请参阅https://developer.apple.com/documentation/swift/string上的String文档。这里的复杂性是相同的字符串具有不同的字节序列表示，这取决于所使用的编码。一种方法是使用init(cString:encoding:)。例如，如果您知道UnsafePointer<Int8>变量buf指向的缓冲区被编码为ASCII，则可以得到如下字符串：

let s = String.init(cString: buf, encoding: String.Encoding.ascii)

＆＃39; UnsafePointer <INT8>＆＃39;没有会员＆＃39; toString＆＃39;

1 个答案: