Qt - 自定义信号发送整数 [英] Qt - custom signal sending an integer

问题描述

我有一系列自定义按钮。我想创建一个自定义信号，当连接到一个以整数作为参数的插槽时，会向它发送一个变量。

所以，例如，假设我有10个按钮，每个按钮都有一个从0到9的id。我将它们全部连接到一个函数，它接受一个整数参数。该函数在被调用时会打印出它的参数。现在，当我按下按钮4时，我想看到我的屏幕上印有4个。



我以前从未创建过自定义信号，所以我会非常感谢任何帮助。



我尝试过：



我还没有尝试过任何东西。我只创建了这个类。

I have an array of custom buttons. I want to create a custom signal, which, when connected to a slot, which takes an integer as an argument, will send a variable to it.
So for example, let's say I've got 10 buttons, each of them has an id from 0 to 9. I connect all of them to a single function, which takes an integer argument. The function, when called, prints it's argument. Now when I press button 4, I want to see a 4 printed on my screen.

I've never created a custom signal before, so I'd be very grateful for any help.

What I have tried:

I haven't tried anything yet. I've only created the class.

推荐答案

只需要实现一个 QPushButton :: clicked（）插槽连接到多个按钮。在内部 sender（）转换为 QPushButton * 以访问该按钮并识别它。然后，您可以使用其他参数发出用户定义的信号。



另一种方法是使用C ++ 11 lambda：

Just implement a QPushButton::clicked() slot that is connected to multiple push buttons. Inside that cast sender() to QPushButton* to access the button and identify it. You can then emit a user defined signal with additional parameters.

Another method would be using a C++11 lambda:

int counter = 1;

// Create button or access it using the ui member 
//QPushButton *button = new QPushButton;

button->setProperty("myId", counter++);
connect(button, &QPushButton::clicked, [this, button](){
    qDebug() << button->property("myId").toString();
    ui->label->setText(button->text());
});

// Repeat for the other buttons

以上是使用属性系统提供ID，将其打印到调试窗口并为按钮的标题文本设置标签。

The above is using the property system to provide IDs, printing it to the debug window and setting a label to the button's caption text.

这篇关于Qt - 自定义信号发送整数的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！