如何在Qt中的表单之间传输数据序列

Question

Assume I have 2 forms in a Qt application. I need to transfer data between 2 forms many times so I used the loop to do this. I just wanna get result from Form 2 before Form 1 is continue to loop. This is my desired intention:

When I used the loop normally, the loop began at i = 1 and sent data to Form 2. Before Form 2 returned result to Form 1, Form 1 was continue to send data with i = 2.

Could you give me some solutions?

Thanks!

Answer 1

You can use signal slot concept to achieve this,

if form1 has object of form2 (Composition)

you can do

 connect(this,SIGNAL(sendData(DataClass),ptr_form2,SLOT(receiveData(DataClass));
 connect(ptr_form2,SIGNAL(acknowledge()),this,SLOT(resendData()));

ptr_form2 is reference of form2

DataClass is you data this could be anytype.replace it with your class object or any data type

 //sendData is signal, in form1
 signals: void sendData(DataClass);

 //resendData is slot in form1
 private slots: void resendData()
 {
     emit sendData(objData); // objData is your data
 }

 //acknowledge is signal in form2
 signals: void acknowledge(); 

 //receiveData is public slot in form2
 public slots: void receiveData(DataClass data)
 {
     /* 
           Do you activity here
      */
     emit acknowledge(); // Emit Acknowledge
  }

if you have reference of both forms in any third form or class then you can do
let ptr_form1 is reference of form1
let ptr_form2 is reference of form2

 connect(ptr_form1 ,SIGNAL(sendData(DataClass),ptr_form2,SLOT(receiveData(DataClass));
 connect(ptr_form2,SIGNAL(acknowledge()),ptr_form1 ,SLOT(resendData()));