EmWin学习课堂_小白EmWin_EmWin快速入门_EmWin用Button控件显示文本

说到EmWin显示文本&＃xff0c;大概就是设置字体大小&＃xff0c;设置背景颜色&＃xff0c;清屏&＃xff08;背景颜色更新&＃xff09;&＃xff0c;设置文本颜色&＃xff0c;设置文字显示格式&＃xff0c;再就是显示了&＃xff1a;

GUI_SetFont(&GUI_Font8x16);
GUI_SetBkColor(GUI_BLUE);
GUI_Clear();
GUI_SetColor(GUI_RED);
GUI_SetTextMode(GUI_TM_NORMAL);
GUI_DispStringAt("I AM A STRING FOR TEST",0,200);

如果您要是不需要太精细的控制&＃xff0c;甚至就一句显示&＃xff0c;也成&＃xff1a;

GUI_DispStringAt("I AM A STRING FOR TEST",0,200);

到了Button控制显示文字我也没觉得会有什么不同&＃xff0c;无非就是在回调函数里面按钮按下的那种情况下displaystring

case WM_NOTIFY_PARENT:Id &＃61; WM_GetId(pMsg->hWinSrc);NCode &＃61; pMsg->Data.v;switch(Id) {case ID_BUTTON_0: // Notifications sent by &＃39;Button&＃39;switch(NCode) {case WM_NOTIFICATION_CLICKED:GUI_SetFont(&GUI_Font8x16);GUI_SetBkColor(GUI_BLUE);GUI_Clear();GUI_SetColor(GUI_RED);GUI_SetTextMode(GUI_TM_NORMAL);GUI_DispStringAt("I AM A STRING FOR TEST",0,200);break;case WM_NOTIFICATION_RELEASED:break;}

现象如下&＃xff0c;按下了button&＃xff0c;背景颜色没变&＃xff0c;没有文本显示&＃xff1a;

查资料和手册发现&＃xff0c;绘制的对象&＃xff0c;不是当前的显示窗口&＃xff0c;而是“画板”&＃xff0c;但是需要占用当前的窗口&＃xff0c;所以在绘制之前&＃xff0c;保存原窗口&＃xff0c;绘制之后&＃xff0c;打开原窗口&＃xff0c;就把画板绘制到窗口上。这样就显示了&＃xff1a;

回调函数先加一个hWinOld&＃xff1a;

static void _cbDialog(WM_MESSAGE * pMsg) {WM_HWIN hItem,hWinOld;int NCode;int Id;

然后就是“保存原窗口”&＃xff0c;画板绘制&＃xff0c;显示经过“画板”变化的原窗口&＃xff1a;

case WM_NOTIFY_PARENT:Id &＃61; WM_GetId(pMsg->hWinSrc);NCode &＃61; pMsg->Data.v;switch(Id) {case ID_BUTTON_0: // Notifications sent by &＃39;Button&＃39;switch(NCode) {case WM_NOTIFICATION_CLICKED:hWinOld &＃61; WM_SelectWindow(WM_GetClientWindow(pMsg->hWin));GUI_DispStringAt("I AM A STRING FOR TEST",150,200);/* 配置回之前选择的目标窗口 */WM_SelectWindow(hWinOld);break;case WM_NOTIFICATION_RELEASED:break;}