How to clear previous Png Image in mfc?

Question

4.50/5 (2 votes)

See more:

C++

void CPictureCtrl::FreeImage()
{
FreeData();
Graphics graphics( GetDC()->GetSafeHdc() );
graphics.Clear(Color::Transparent);
// or any other color ; see Gdiplus..
}

C++

m_picCtrl.FreeImage();
	CFile picFile;
	if(picFile.Open(_T("acoustic grand piano_small.png"), CFile::modeReadWrite | CFile::typeBinary))
	{
		cout("opened");
		BYTE* pBuffer = new BYTE[(unsigned int)picFile.GetLength()];
		if(pBuffer != NULL)
		{
			picFile.Read(pBuffer, (UINT)picFile.GetLength());

			//Load the Image
			cout("displayed");
				m_picCtrl.Load(pBuffer, (size_t)picFile.GetLength());

			delete pBuffer;
		}
	}

When I freeImage which should clear the png and display new i am getting black background. But I need transparent background.

My objective is display png and when I display new png it should clear the previous pic.

I have used CStatic control to display the png.

Posted 3-May-12 18:54pm

chaiein

Updated 3-May-12 18:55pm

v2

Add a Solution

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

chaiein · Accepted Answer · 2012-05-03T20:02:00

Add

C++

Invalidate(true);

C++

m_picCtrl.FreeImage();
    CFile picFile;
    if(picFile.Open(_T("acoustic grand piano_small.png"), CFile::modeReadWrite | CFile::typeBinary))
    {
        cout("opened");
        BYTE* pBuffer = new BYTE[(unsigned int)picFile.GetLength()];
        if(pBuffer != NULL)
        {
            picFile.Read(pBuffer, (UINT)picFile.GetLength());

            //Load the Image
            cout("displayed");
                m_picCtrl.Load(pBuffer, (size_t)picFile.GetLength());

            delete pBuffer;
        }
    }
Invalidate(true);