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Using RGB() to Change Colors: 1. Open Borland C++ Builder. 2. Place a Button on the form. 3. Place 3 Edit boxes on the form in a row, make them blank with a width of 40 each. 4. Place a Panel on the form. 5. Double click Button1. 6. Type the following red code in the Button1Click function: //This is what the Button1Click function should look like: void __fastcall TForm1::Button1Click(TObject *Sender) { int nR = 0, nG = 0, nB = 0; nR = atoi(Edit1->Text.c_str()); nG = atoi(Edit2->Text.c_str()); nB = atoi(Edit3->Text.c_str()); Panel1->Color = (TColor)RGB(nR, nG, nB); } //--------------------------------------------------------------------------- 7. Run the program, type a value from 0 to 255 in each of the edit boxes. Click the button. The panel will change to the RGB value you entered. Edit1 = RED, Edit2 = GREEN and Edit3 = BLUE. There is no error trapping here so be sure that you enter only numbers. Note: atoi() converts a char to an int and .c_str() converts an AnsiString to a char. |