如何将十字线添加到pyqt5图形

问题描述

我需要添加一个十字准线，就像页面上的此处一样。crosshair 十字准线应在鼠标后面移动。 Internet上关于此主题的示例很少。 到处都有“ pyqtgraph”。我听不懂。 我想使用按钮添加和删除十字线。 我可以只用一个pyqt吗？

使用此代码作为添加十字准线的基础。

from PyQt5 import QtCore,QtGui,QtWidgets,QtChart
from PyQt5.QtCore import *
from PyQt5.QtChart import *
import math
import numpy as np

mas =[1.33,1.15,1.55,1.65,1.64,1.91,1.33,2.3,1.5,1.35,2.52,1.77,1.7,1.87,2.0,1.73,2.1,1.92,1.71,1.22,2.7,2.1]
x = len(mas)
x_ = x - 1

class MainWindow(QtWidgets.QMainWindow):
    def __init__(self,start = 1,parent=None):
        self.start = start
        super().__init__(parent)

        self.step = 30
        self._chart_view = QtChart.QChartView()
        self.scrollbar = QtWidgets.QScrollBar(
            QtCore.Qt.Horizontal,sliderMoved=self.onAxisSliderMoved,pageStep=self.step,)

        self.scrollbar.setRange(0,x_)

        central_widget = QtWidgets.QWidget()
        self.setCentralWidget(central_widget)

        lay = QtWidgets.QVBoxLayout(central_widget)
        for w in (self._chart_view,self.scrollbar):
            lay.addWidget(w)

        self._chart = QtChart.QChart()
        self._line_serie = QtChart.QLineSeries()

        for i in range(0,len(mas)):
            self._line_serie.append(QtCore.QPointF(i,mas[i]))

        min_x,max_x = 0,x_
        self._chart.addSeries(self._line_serie)

        axisX = QValueAxis()
        axisX.setTickCount(5)
        axisX.setLabelFormat("%d")
        self._chart.addAxis(axisX,Qt.AlignBottom)
        self._line_serie.attachAxis(axisX)

        axisY = QValueAxis()
        self._chart.addAxis(axisY,Qt.AlignLeft)
        self._line_serie.attachAxis(axisY)

        self._chart.legend().hide()
        self._chart_view.setChart(self._chart)
        self.lims = np.array([min_x,max_x])
        self.onAxisSliderMoved(self.scrollbar.value())

        self.adjust_axes(self.start,31)

    def adjust_axes(self,value_min,value_max):
        if value_min >= 0 and value_max >= 0 and value_max <= x_ and value_max > value_min:
            self._chart.axisX(self._line_serie).setRange(value_min,value_max)

    @QtCore.pyqtSlot(int)
    def onAxisSliderMoved(self,value):
        value2 = value + self.step
        value1 = value
        if value2 >= x_:
            value2 = x_
            value1 = value2 - self.step
        self.adjust_axes(math.floor(value1),math.ceil(value2))


if __name__ == "__main__":
    import sys

    app = QtWidgets.QApplication(sys.argv)
    w = MainWindow(start = 0)
    w.show()
    sys.exit(app.exec_())

解决方法

一种可能的解决方案是重写QChartView的drawForeground方法，该方法应基于鼠标位置绘制线条：

function Test([bool]$Skip,[bool]$SkipPerm,[String]$ProcessName,[String]$StartString,[String]$WindowName)
{
    If([bool]$Skip -eq "False" -and [bool]$SkipPerm -eq "False"){        <# If this server doesn't need to be skipped (the function is self recursive) then attempt to start or restart #>          
  

        $ServerToStart = "[String]$StartString"
        $process = Get-Process | Where-Object MainWindowTitle -eq '[String]$WindowName'

        If (!($process)) {              <# if it is not running,start it now #>
            Start-Process $ServerToStart

            If ($Global:Attempt -le $global:RestartCounts){       <# if restart permissible,then attempt to start #>
            Write-Host "Not Running! [String]$ServerName is re-starting..." 
            }

            Else{write-host "$RestartAttempts Attempts made,all failed. Attempting to start next instance."    <# if restart not permissible,say it's tried x amount and skip this server permanently #>
            [bool]$SkipPerm = "True"           
            }
             
            $process = Get-Process | Where-Object MainWindowTitle -eq '[String]$WindowName' <#need to re-define process here or it bugs out#>
            If ($process) {                  <# check if server succesfully started #>
                [bool]$Skip = "True"           <# this server is started,so it doesn't need to try or check again #>
                Write-Host "Successfully started [String]$ServerName"
            }

            else{                      <# if didn't start then #>
                If ($Global:Attempt -le $global:RestartCounts) {                              <# check if restart permissible #>
                    Write-Host "ERROR! Instance failed to start,trying again" 
                    $global:Attempt = $global:Attempt + 1            <# increment fail counter #>
                    Test          <# call self again and try another restart #>
                }
                Else{                               <# server succesfully restarted,reset attempts to 0 and skip this server instance tempoerarily #>
                $global:Attempt = 0
                $global:Skip = "True"
                Test
                }
            }
        }

        else{
            Write-Host "Instance is running"
            $global:Skip = "True"                       
        }
    }

    elseif($Global:SkipPerm -eq "True"){                     <#if server failed permanently then display a message and skip this server forever #>
    write-host "Instance is OFFLINE,skipped"
}