c++qt

Qt grab widget and save image

I have the following problem. I want to grab a widget and save it as an image. I want to save it as png, jpeg, and tiff. I have written the following code:

QString s =  QFileDialog::getSaveFileName(this, "Save as", "Choose a filename", "PNG(*.png);; TIFF(*.tiff *.tif);; JPEG(*.jpg *.jpeg)");

std::string current_string = s.toLocal8Bit().constData();
//current_string = current_string + ".png";

char * buffer = new char[current_string.length()];
std::string temp = buffer;
char* temp2 = &temp[0];
strcpy(buffer, current_string.c_str());

char* pch = strtok (temp2,".");
pch = strtok (NULL, ".");


if(!QPixmap::grabWindow(m_widget->winId()).save(buffer,pch))
{
    QMessageBox::warning(this, "File could not be saved", "ok", QMessageBox::Ok);
}

This works fine on my laptop. When I make a Visual Studio Setup it also works fine on my laptop, but when I install it on another pc, then the png format works fine (saves the right image), but jpeg and tif can't be saved. Then I tried it on a further pc, but there I tried it directly in Visual Studio with the project file. There I have all project settings like on my pc etc. and there jpeg and tif don't work. PNG works but it only saves a white image on that pc. Further I also tried there the installation file and its the same PNG = white image.

Can anyone help me?

Solution

  • Here is the simplest way to save a widget as an image. This approach works on Qt 5:

    ui->myWidget->grab().save("image.png");

    Qt doc.: