用Swift创建NSAlert

Question

我在Objective中有要创建的代码和NSAlert，但是现在我想用Swift创建它。

此警报用于确认用户希望删除文档。

我想要“删除”按钮然后运行删除功能和“取消”一个只是为了解除警报。

我怎么用斯威夫特写这个？

NSAlert *alert = [[[NSAlert alloc] init] autorelease];
[alert addButtonWithTitle:@"Delete"];
[alert addButtonWithTitle:@"Cancel"];
[alert setMessageText:@"Delete the document?"];
[alert setInformativeText:@"Are you sure you would like to delete the document?"];
[alert setAlertStyle:NSWarningAlertStyle];
[alert beginSheetModalForWindow:[self window] modalDelegate:self didEndSelector:@selector(alertDidEnd:returnCode:contextInfo:) contextInfo:nil];

Answer 1

beginSheetModalForWindow:modalDelegate在OSX10.10Yosemite中是不可取的。

Swift 2

func dialogOKCancel(question: String, text: String) -> Bool {
    let alert: NSAlert = NSAlert()
    alert.messageText = question
    alert.informativeText = text
    alert.alertStyle = NSAlertStyle.WarningAlertStyle
    alert.addButtonWithTitle("OK")
    alert.addButtonWithTitle("Cancel")
    let res = alert.runModal()
    if res == NSAlertFirstButtonReturn {
        return true
    }
    return false
}

let answer = dialogOKCancel("Ok?", text: "Choose your answer.")

这将根据用户的选择返回true或false。

NSAlertFirstButtonReturn表示添加到对话框中的第一个按钮，这里是"OK“按钮。

Swift 3

func dialogOKCancel(question: String, text: String) -> Bool {
    let alert = NSAlert()
    alert.messageText = question
    alert.informativeText = text
    alert.alertStyle = NSAlertStyle.warning
    alert.addButton(withTitle: "OK")
    alert.addButton(withTitle: "Cancel")
    return alert.runModal() == NSAlertFirstButtonReturn
}

let answer = dialogOKCancel(question: "Ok?", text: "Choose your answer.")

Swift 4

我们现在使用枚举作为警报的样式和按钮选择。

func dialogOKCancel(question: String, text: String) -> Bool {
    let alert = NSAlert()
    alert.messageText = question
    alert.informativeText = text
    alert.alertStyle = .warning
    alert.addButton(withTitle: "OK")
    alert.addButton(withTitle: "Cancel")
    return alert.runModal() == .alertFirstButtonReturn
}

let answer = dialogOKCancel(question: "Ok?", text: "Choose your answer.")

Answer 2

我想这可能对你有用..。

let a = NSAlert()
a.messageText = "Delete the document?"
a.informativeText = "Are you sure you would like to delete the document?"
a.addButtonWithTitle("Delete")
a.addButtonWithTitle("Cancel")
a.alertStyle = NSAlert.Style.WarningAlertStyle

a.beginSheetModalForWindow(self.view.window!, completionHandler: { (modalResponse) -> Void in
    if modalResponse == NSAlertFirstButtonReturn {
        print("Document deleted")
    }
})

Answer 3

更新Jose Hidalgo对Swift 4的回答：

let a: NSAlert = NSAlert()
a.messageText = "Delete the document?"
a.informativeText = "Are you sure you would like to delete the document?"
a.addButton(withTitle: "Delete")
a.addButton(withTitle: "Cancel")
a.alertStyle = NSAlert.Style.warning

a.beginSheetModal(for: self.window!, completionHandler: { (modalResponse: NSApplication.ModalResponse) -> Void in
    if(modalResponse == NSApplication.ModalResponse.alertFirstButtonReturn){
        print("Document deleted")
    }
})