SignalTransition QML Type

SignalTransition 类型提供基于 Qt 信号的转换。更多

Import Statement:	`import QtQml.StateMachine 6.9`
Inherits:	QSignalTransition

所有成员（包括继承成员）的列表

属性

guard : bool
signal : signal

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, 和TimeoutTransition 。

属性文档

guard : bool

保护条件（Guard Condition）影响状态机的行为，只有当它们评估为 true 时才启用转换，当它们评估为 false 时才禁用转换。

当与此信号转换相关的信号发出时，会对保护条件进行评估。在保护条件中，可以使用信号的参数，如下例所示。

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")
    }
}

另请参见 signal 。

signal : signal

与此信号转换相关的信号。

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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