STM32 ADC conversion using HAL
In your original code, set the End of Conversion Selection to disabled.

 hadc1.Init.EOCSelection = DISABLE;


It turned out that #define ADC_EOC_SEQ_CONV ((uint32_t)0x00000000) value is equal to DISABLE. So actually the EOCSelection should be configured as:  
to be able to poll the ADC multiple times.

Then you can read the ADC continously without stopping and starting the ADC:

int main(void)
{
    HAL_Init();
    SystemClock_Config();
    ConfigureADC();

    HAL_ADC_Start(&amp;hadc1);
    while(1)
    {
        if (HAL_ADC_PollForConversion(&amp;hadc1, 1000000) == HAL_OK)
        {
            ADCValue = HAL_ADC_GetValue(&amp;hadc1);
        }
    }
}


This way it worked fine for me.

Since HAL is a quite new library there are not a lot of resources to be find but not impossible. I learned a lot from this tutorial, it demonstrates all possible ADC useage step by step; from simple polling, to using interrupts and DMA.