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SignalTransition QML Type

SignalTransition 类型提供基于 Qt 信号的过渡。更多内容...

Import Statement: import QtQml.StateMachine 6.12
Inherits:

QSignalTransition

属性

详细说明

SignalTransition 是Qt State Machine QML API 的一部分。

使用示例

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 以及TimeoutTransition 。

属性文档

guard : bool

守护条件通过仅在评估结果为真时允许状态转换、在评估结果为假时禁止状态转换,从而影响状态机的行为。

当与该信号转换相关的信号被发出时,将对守护条件进行求值。在守护条件中,可以像下面的示例所示那样使用该信号的参数。

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

与该信号跳变相关的信号。

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
            }
        }
    }
}

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