Flickering button with PNG image

**Vrishabh** · 25-06-2011

I have noticed an issue in the project which you have mentioned over here. Well I have noticed that the location of the button is changing dynamically. The button is having the PNG image which is having transparent and background is also seems to be transparent. When I am moving the button it gets flickers. Let me know if you are having any issue to fix the matter of mine. Thanks a lot in advance.

**Dwarner** · 25-06-2011

Looking at the situation which you have provided over here I am suggesting that you should try to fix the matter of yours. I recommend that you should try with the double buffering by using the following piece of code.

Code:

Form1(void)
{
InitializeComponent();
SetStyle(ControlStyles::UserPaint, true);
SetStyle(ControlStyles::AllPaintingInWmPaint, true);
SetStyle(ControlStyles:DoubleBuffer, true);
UpdateStyles();
}

**Author** · 25-06-2011

I think you need to use the paint method of the button which you can redraw the button image in this particular situation. You should use the following code and see whether it is working or not.

Code:

private: System::Void Button_Palanca_IZQ_Paint(System::Object^ sender, System::Windows::Forms::PaintEventArgs^ e) {
g->DrawImage(image,loc);
}

you should copy and paste the above mentioned code into the project and see whether it is working or not.

**Jacques25** · 25-06-2011

Well I am suggesting following code which you can use to fix the matter of yours and see whether it is working or not.

Code:

// Load background image from file and adjust resolution

      Bitmap ^bmpTemp = gcnew Bitmap("..\\palancaBase_upsampled.bmp");
      Diagnostics::Trace::Assert(bmpTemp != nullptr, "Construction of background bitmap from file failed");
      Graphics ^grTemp = CreateGraphics();
      bmpTemp->SetResolution(grTemp->DpiX, grTemp->DpiY);
      BackgroundImage = bmpTemp;

I am sure that the above mentioned code would definitely help you pout to fix the matter of yours.

**Vandam** · 25-06-2011

I am suspecting that you have placed the button on the panel and hence you will not have any direct to the style. I recommend that you have to use the custom panel. Also there could be an issue with Overide OnPaint or there could be an issue with Paint event. You should derive a class from the user control and IDE should be provide support for this. You should create the same and append with the new class and s let me know about the result.

**Steyn** · 28-06-2011

An invisible button in to the repainting would not make any repainting so I think we have to work with the timer tick handler which is responsible for the movement of the button into the project if yours. in order to implement the same you have to use the following code into the project of yours.

Code:

private: System::Void timer1_Tick(System::Object^  sender, System::EventArgs^  e) {

             loc+=5;
             if(loc>600) loc=0;
             Drawing::Region ^rgToInvalidate = gcnew Drawing::Region(button1->Bounds);  // Store old button area
             button1->Location = System::Drawing::Point(loc,loc);
             rgToInvalidate->Union(button1->Bounds);  // Add new button area

             // Invalidate the union of the old and new button areas

             Invalidate(rgToInvalidate);
           }

The above mentioned code would make the repainting of the button so try the same and let me know whether it is working or not.