The SignalTransition type provides a transition based on a Qt signal. 更多...
导入语句: | import QtQml.StateMachine 6.2 |
Since: | Qt 5.4 |
继承: | QSignalTransition |
SignalTransition is part of Qt State Machine QML API .
import QtQuick import QtQml.StateMachine as DSM Rectangle { DSM.StateMachine { id: stateMachine initialState: state running: true DSM.State { id: state DSM.SignalTransition { targetState: finalState signal: button.clicked guard: guardButton.checked } } DSM.FinalState { id: finalState } onFinished: Qt.quit() } Row { spacing: 2 Button { id: button text: "Finish state" } Button { id: guardButton checkable: true text: checked ? "Press to block the SignalTransition" : "Press to unblock the SignalTransition" } } }
另请参阅 StateMachine , FinalState ,和 TimeoutTransition .
guard : bool |
Guard conditions affect the behavior of a state machine by enabling transitions only when they evaluate to true and disabling them when they evaluate to false.
When the signal associated with this signal transition is emitted the guard condition is evaluated. In the guard condition the arguments of the signal can be used as demonstrated in the example below.
import QtQuick import QtQml.StateMachine as DSM Rectangle { Button { anchors.fill: parent id: button DSM.StateMachine { DSM.State { DSM.SignalTransition { targetState: finalState signal: button.mysignal // the guard condition uses the mystr string argument from mysignal guard: mystr == "test" } } DSM.FinalState { id: finalState } } // define the signal the SignalTransition is connected with signal mysignal(mystr: string) // on clicking the button emit the signal with a single string argument onClicked: button.mysignal("test") } }
另请参阅 signal .
signal : signal |
The signal which is associated with this signal transition.
import QtQuick import QtQml.StateMachine as DSM Rectangle { Button { anchors.fill: parent id: button DSM.StateMachine { DSM.State { DSM.SignalTransition { targetState: finalState signal: button.clicked } } DSM.FinalState { id: finalState } } } }