如何防止简单的 NSAlert 被忽略?
F.ex.,当应用程序启动时,我显示一个包含 NSTextField 的 NSAlert。用户应输入密码。仅当密码正确时,才允许用户使用应用程序,如果不正确(如果密码不正确),则警报应留在那里并再次要求输入密码。
到目前为止,这是我的代码(用于创建警报):
func applicationDidFinishLaunching(_ aNotification: Notification){
let alert = NSAlert()
alert.addButton(withTitle: "Send")
alert.delegate = self
alert.alertStyle = .informational
alert.messageText = "Password - Login"
alert.informativeText = "Please type in your password: "
let txt = NSTextField(frame: NSRect(x: 0, y: 0, width: 200, height: 24))
txt.stringValue = "Password:"
alert.accessoryView = txt
alert.beginSheetModal(for: NSApplication.shared().mainWindow!) { (response) in
if (response == NSAlertFirstButtonReturn) {
// the alert closes here, is there any way to prevent this?
} else {
print("No value.")
}
}
操作系统:OS X Sierra、Swift 3