CODEWITHSUNDEEP
pythonpyqt
Karpov
Karpov

Reputation: 423

PyQt custom dialog -- how to get the return value?

Using PyQt5, I'm trying to get a custom dialog (containing a simple QListWidget) to return a value. I know similar questions have been asked before but somehow I don't seem to get the answers to work.

The custom dialog is in this class:

class ListSelection(QDialog):
    def __init__(self, item_ls, parent=None):
        super(ListSelection, self).__init__(parent)
        self.result = ""
        #================================================= 
        # listbox
        #================================================= 
        self.listWidget = QListWidget()
        for item in item_ls:
        w_item = QListWidgetItem(item)
        self.listWidget.addItem(w_item)
        self.listWidget.itemClicked.connect(self.OnSingleC lick)
        self.listWidget.itemActivated.connect(self.OnDoubl eClick)
        layout = QGridLayout()
        row=0
        layout.addWidget(self.listWidget,row,0,1,3) #col span=1, row span=3
        #================================================= 
        # OK, Cancel
        #================================================= 
        row +=1
        self.but_ok = QPushButton("OK")
        layout.addWidget(self.but_ok ,row,1)
        self.but_ok.clicked.connect(self.OnOk)

        self.but_cancel = QPushButton("Cancel")
        layout.addWidget(self.but_cancel ,row,2)
        self.but_cancel.clicked.connect(self.OnCancel)

        #================================================= 
        #
        #================================================= 
        self.setLayout(layout)
        self.setGeometry(300, 200, 460, 350)

    def OnSingleClick(self, item):
        self.result = item.text()

    def OnDoubleClick(self, item):
        self.result = item.text()
        self.close()
        return self.result

    def OnOk(self):
        if self.result == "":
            QMessageBox.information(self, "Error",
            "One item must be selected")
            return 
        self.close()
        return self.result

    def OnCancel(self):
        self.close()

    def GetValue(self):
        return self.result

And this is what the calling function does:

def SomeFunction()
    ls = ['apples','bananas','melons']
    lb = ListSelection(ls)
    if lb.exec_():
        value = lb.GetValue()
        print(value)

The problem is, this does not capture any value.

Thanks!

Upvotes: 1

Views: 9662

Answers (1)

Mel
Mel

Reputation: 6065

The exec_ function does not return True, so you never print the value.

According to the documentation, it return a QDialogCode, an int. I tested with the code below, and it returns 0 (which evaluate to False)

def SomeFunction():
    ls = ['apples','bananas','melons']
    lb = ListSelection(ls)
    returnCode=lb.exec_()
    print(returnCode)
    value = lb.GetValue()
    print(value)

So just don't put an if, and it will print the value.

Edit:

I guess the correct behaviour would be to print the value if the user press Ok, and print nothing if the user press Cancel.

So instead of using QDialog.close(), you can use QDialog.done(int), the integer being the QDialogCode. This way you can keep your if statement.

Upvotes: 3

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