[Win32SDK基本]Button Control（1）Push Button 和 BM_SETIMAGE

本文由CSDN用户zuishikonghuan所作，转载请注明出处：http://blog.csdn.net/zuishikonghuan/article/details/46649211

前两篇中介绍了Static Control，这几篇来介绍一下Button Control

Button Control有很多类型，下图中展示了这一点（图片来自MSDN：https://msdn.microsoft.com/en-us/library/windows/desktop/bb775947(v=vs.85).aspx）

这一篇中就介绍一下Push Button

MSDN:

A push button is a rectangle containing an application-defined text label, an icon, or a bitmap that indicates what the buttohe user selects it.

A push button can be one of two styles, standard or default, as defined by the constants BS_PUSHBUTTON and BS_DEFPUSHBUTTON. A standard push button is typically used to start an operation. It receives the keyboard focus when the user clicks it. A default push button is typically used to indicate the most common or default choice, such as closing the dialog box. It is a button that the user can select by simply pressing ENTER when no other push button in the dialog box has the input focus.

When the user clicks a push button, it receives the keyboard focus. The system sends the button's parent window a WM_COMMAND message that contains the BN_CLICKED notification code.

The split button is a special kind of push button introduced in Windows Vista and Version 6.00. A split button is divided into two parts. The main part functions like a regular or default push button. The second part has an arrow pointing downward. Typically a menu is displayed when the arrow is clicked.

A split button has the BS_SPLITBUTTON style, or the BS_DEFSPLITBUTTON style if it is the default button in a dialog box. You can modify the appearance of the button by using the BCM_SETSPLITINFO message or the corresponding Button_SetSplitInfo macro.

When the user clicks on the main part of the split button, it sends a BN_CLICKED notification just like a normal push button. But when the user clicks on the down arrow, it sends a BCN_DROPDOWN notification. It is the application's responsibility to display a menu in response to BCN_DROPDOWN.

Windows Vista and Version 6.00 also introduced another kind of push button, the command link. Visually, a command link is very different from a normal push button, but it has the same functionality. A command link typically displays an arrow icon, a line of text, and additional text in a smaller font.

这里取其中的关键一部分bing翻译：

按 下 按钮 可以 是 两种 风格 ， 标准 或 默认情况下 ， 由 BS_PUSHBUTTON 和 BS_DEFPUSHBUTTON 的 常量 定义 。 一个 标准 的 按钮 通常 用于 启动 操作 。 当 用户 单击 它 时 ， 它 接收 键盘 焦点 。 默认 按钮 通常 用于 指示 最 常见 或 默认 选项 ， 如 关闭 对话框 。 它 是 一个 按钮 ， 用户 可以 选择 只需 按 enter 键 时 在 对话框 中 没有 其他 按钮 具有 输入 的 焦点 。

当 用户 单击 按钮 时 ， 它 接收 键盘 焦点 。 系统 将 按钮的 父 窗口 发送 WM_COMMAND 消息 来 包含 发送的 BN_CLICKED 通知 代码 。

好了，无非是创建几个子窗口而已，相信各位在之前的两篇文中已经大致明白了，接下来，就是创建按钮了，这次创建两个Push Button，一个是默认按钮，另一个是普通按钮。

还是以我的博客“[Win32SDK基本] 窗口详解（超详细）”（地址：http://blog.csdn.net/zuishikonghuan/article/details/46378475）为模板，进一步编写。

先创建全局变量

HWND button1 = 0;
HWND button2 = 0;

在WM_CREATE消息里添加一下代码，即可创建Push Button

		button1 = CreateWindow(TEXT("Button"), TEXT("默认按钮"), WS_CHILD | WS_VISIBLE | BS_DEFPUSHBUTTON, 10, 60, 100, 30, hwnd, (HMENU)4, (HINSTANCE)GetWindowLong(hwnd, GWL_HINSTANCE), NULL);
		SendMessage(button1, WM_SETFONT, (WPARAM)GetStockObject(17), 0);

接下来，我们创建一个标准按钮

		button2 = CreateWindow(TEXT("Button"), TEXT("标准按钮"), WS_CHILD | WS_VISIBLE | BS_PUSHBUTTON, 10, 100, 100, 30, hwnd, (HMENU)5, (HINSTANCE)GetWindowLong(hwnd, GWL_HINSTANCE), NULL);
		SendMessage(button2, WM_SETFONT, (WPARAM)GetStockObject(17), 0);

效果图：

如何得到按钮的单机事件呢，当然是利用消息，和菜单非常类似

case WM_COMMAND:
		int id;
		int ent;
		ent = HIWORD(wParam);//通知吗
		id = LOWORD(wParam);//子窗口ID
		//判断菜单ID，注意不需要再判断HIWORD(wParam)了，因为菜单的通知码是一个定值（和控件不一样）
		switch (id)
		{
		case 3://这里使用在RC资源里面注册的菜单号
			MessageBox(hwnd, TEXT("菜单3被点击"), TEXT(""), 0);
			break;
		}
		//判断按钮的单机事件
		if (ent == BN_CLICKED){
			switch (id)
			{
			case 4://按钮的子窗口ID
				MessageBox(hwnd, TEXT("按钮被点击"), TEXT(""), 0);
				break;
			}
		}
		break;

只是注意判断一下 HIWORD(wParam) 通知码就行了， BN_CLICKED 是按钮单机

创建带图片（位图）或图标的按钮

核心是使用 BM_SETIMAGE 消息

MSDN：https://msdn.microsoft.com/en-us/library/windows/desktop/bb761822(v=vs.85).aspx

wParam
图像与按钮相关联的类型。此参数可以是下列值之一:
IMAGE_BITMAP 位图
IMAGE_ICON 图标

lParam
位图或图标句柄

文本、图标，或两者都有的按钮控件的外观取决于BS_ICON和BS_BITMAP 的风格，和是否调用BM_SETIMAGE消息。可能的结果如下所示:

下面，创建一个只有一个图标的按钮：

		HBITMAP oldimage;
		HICON hicon;

<pre class="cpp" name="code">		button3 = CreateWindow(TEXT("Button"), TEXT(""), WS_CHILD | WS_VISIBLE | BS_PUSHBUTTON | BS_ICON, 10, 140, 100, 50, hwnd, (HMENU)6, (HINSTANCE)GetWindowLong(hwnd, GWL_HINSTANCE), NULL);
		hicon = LoadIcon((HINSTANCE)GetWindowLong(hwnd, GWL_HINSTANCE), TEXT("ICON_1"));
		oldimage = (HBITMAP)SendMessage(button3, BM_SETIMAGE, IMAGE_ICON, (LPARAM)hicon);
		if (oldimage != NULL)
		{
			DeleteObject(oldimage);
		}
		DeleteObject(hicon);

再创建一个既有图标又有文字的按钮

<pre class="cpp" name="code">		hicon = LoadIcon((HINSTANCE)GetWindowLong(hwnd, GWL_HINSTANCE), TEXT("ICON_1"));
		button4 = CreateWindow(TEXT("Button"), TEXT("标准按钮"), WS_CHILD | WS_VISIBLE | BS_PUSHBUTTON , 10, 220, 100, 30, hwnd, (HMENU)7, (HINSTANCE)GetWindowLong(hwnd, GWL_HINSTANCE), NULL);
		SendMessage(button4, WM_SETFONT, (WPARAM)GetStockObject(17), 0);
		oldimage = (HBITMAP)SendMessage(button4, BM_SETIMAGE, IMAGE_ICON, (LPARAM)hicon);
		if (oldimage != NULL)
		{
			DeleteObject(oldimage);
		}
		DeleteObject(hicon);

注意，只有开启了系统风格才能看见文字，否则是看不见文字的，关于系统风格我会在后面详细说