将变量传递到 SLOT - QSignalMapper答案

【问题标题】：Passing variables into SLOTs - QSignalMapper将变量传递到 SLOT - QSignalMapper
【发布时间】：2014-08-12 14:16:59
【问题描述】：

我正在尝试对两个图像上传使用相同的图像上传功能。

所以在点击上传按钮时，我需要将 self.UploadStudentPhoto 或 self.UploadParentsPhoto 传递给 self.UploadFile() 函数，对应于按下的按钮。

由于我们无法将变量传递到 SLOT，所以我尝试使用 QSignalMapper，如下所示。

self.UploadStudentPhoto = QLineEdit() #Student Photo location
self.UploadParentsPhoto = QLineEdit() #Parents Photo location
self.ParentsImage = None

self.SignalMapper = QSignalMapper()
self.connect(self.ButtonUpload1,SIGNAL("clicked()"),self.SignalMapper, SLOT("map()"))
self.connect(self.ButtonUpload2,SIGNAL("clicked()"),self.SignalMapper,SLOT("map()"))

self.SignalMapper.setMapping(self.ButtonUpload1, self.UploadStudentPhoto)
self.SignalMapper.setMapping(self.ButtonUpload2, self.UploadParentsPhoto)

但我不确定需要将 SIGNAL("mapped()") 传递给我为文件上传编写的函数的以下行。我应该如何写下一行：

self.connect(self.SignalMapper,SIGNAL("mapped()"), self, self.UploadFile)

上传文件功能如下：

def UploadFile(self, ImagePath, ImageLabel):
    dir = os.path.dirname(".")
    formats = ["*.%s" % unicode(format).lower()\
        for format in QImageReader.supportedImageFormats()]
    self.fname = unicode(QFileDialog.getOpenFileName(self,"Image",dir,"Image (%s)" % " ".join(formats)))
    print self.fname
    ImagePath.setText(self.fname)
    ImagePath.selectAll()
    ImageLabel = QImage()
    ImageLabel.setPixmap(QPixmap.fromImage(ImageLabel))

我看到了很多 QSignalMapper 示例，但我不确定变量是如何传递的。请提出建议。

【问题讨论】：

标签： python qt python-2.7 qt4 pyqt4

【解决方案1】：

实际上，它可以通过在python中使用partial模块将变量传递给connect & SLOT；

在我看来，我建议使用“简单”（我认为）来实现，我将在下面的代码中向您展示；

from functools import partial
.
.
.
        self.StudentPhoto = QLabel() # I know you have this.
        self.ParentsPhoto = QLabel() # I know you have this too.
        self.UploadStudentPhoto = QLineEdit()
        self.UploadParentsPhoto = QLineEdit()
        self.connect(self.ButtonUpload1, SIGNAL("clicked()"), partial(self.UploadFile, self.UploadStudentPhoto, self.StudentPhoto))
        self.connect(self.ButtonUpload2, SIGNAL("clicked()"), partial(self.UploadFile, self.UploadParentsPhoto, self.ParentsPhoto))
.
.
.
    def UploadFile(self, ImagePath, ImageLabel):
        dir = os.path.dirname(".")
        formats = ["*.%s" % unicode(format).lower()\
            for format in QImageReader.supportedImageFormats()]
        self.fname = unicode(QFileDialog.getOpenFileName(self,"Image",dir,"Image (%s)" % " ".join(formats)))
        print self.fname
        ImagePath.setText(self.fname)
        ImagePath.selectAll()
.
.
.

示例参考：http://www.learnpython.org/en/Partial_functions

官方参考：https://docs.python.org/2/library/functools.html

问候，

【讨论】：