GdiplusFlat（4）单色画刷 和 线性渐变画刷

本博文由CSDN博主zuishikonghuan所作，版权归zuishikonghuan所有，转载请注明出处： http://blog.csdn.net/zuishikonghuan/article/details/47271829

在上一篇中，我们说到了通过GdipCreateFromHDC函数将HDC（设备上下文句柄）装换成GDI+的Graphics对象，并讲到了画笔的使用，这一篇就来讲讲画刷。

画刷和画笔差不多，就是画刷是画的实心的图形、

其实画刷有很多种，这里只介绍最常用的两种，分别是单色画刷和线性渐变画刷

还是和以前一样，我们必须自己声明GDI+Flat函数，自己定义GDI+Flat的数据结构。自己动手，丰衣足食。~~

对于画刷的创建和销毁，其实是GDI+调用的GDI+Flat的这几个函数：GdipCreateSolidFill、GdipCreateLineBrush和GdipDeleteBrush

我们把这两个函数自己声明出来！不用那些GDI+类的东西！只用C和Win32的最基本的数据类型！

//画刷
typedef struct _PointF{
	float x;
	float y;
}PointF;
extern "C" int WINAPI GdipCreateSolidFill(unsigned int argb_color,int** brush);
extern "C" int WINAPI GdipCreateLineBrush(PointF* point1, PointF* point2, unsigned int argb_color1,unsigned int argb_color2,int wrapMode,int** lineGradient);
extern "C" int WINAPI GdipDeleteBrush(int* brush);

GdipCreateSolidFill：创建单色画刷

参数1：画刷的ARGB颜色

参数2：指向一个画刷的指针，用于接收返回的画刷，画刷是int*

GdipCreateLineBrush：创建线性渐变画刷

参数1：起点坐标，是我上面定义的PointF结构，PointF结构中：x为横坐标，y为纵坐标

参数2：终点坐标，是我上面定义的PointF结构，PointF结构中：x为横坐标，y为纵坐标

参数3：画刷的起点ARGB颜色

参数4：画刷的终点ARGB颜色

参数5：wrapMode 包围模式：WrapModeTile=0,WrapModeTileFlipX=1,WrapModeTileFlipY=2,WrapModeTileFlipXY=3,WrapModeClamp=4

其中0最为常用，为“平铺模式“。MSDN：https://msdn.microsoft.com/en-us/library/ms534407(v=vs.85).aspx

参数6：指向一个画刷的指针，用于接收返回的画刷，画刷是int*

GdipDeleteBrush：销毁画刷

参数：要销毁的画刷

以上三个函数的返回值：0成功，非0失败

通过画刷画图，以画填充矩形为例：

//画填充矩形
extern "C" int WINAPI GdipFillRectangle(int graphics, int* brush, float x, float y, float width, float height);

GdipFillRectangle：画填充矩形

参数1：Graphics对象

参数2：画刷

参数3-6：矩形左上角的x坐标，y坐标，矩形宽度，矩形高度

例子：

<pre class="cpp" name="code">	case WM_PAINT:
		HDC hdc;
		PAINTSTRUCT ps;
		hdc = BeginPaint(hwnd, &ps);

		int graphics;
		GdipCreateFromHDC(hdc, &graphics);//创建Graphics对象
		GdipCreateSolidFill(0x700000FF, &brush);//创建单色画刷
		GdipFillRectangle(graphics, brush, 10, 10, 60, 60);//用单色画刷填充矩形
		PointF p1; p1 = { 70, 0 };
		PointF p2; p2 = { 170, 0 };
		GdipCreateLineBrush(&p1, &p2, 0xFFFF0000, 0x400000FF, 0, &linebrush);//创建线性渐变画刷
		GdipFillRectangle(graphics, linebrush, 70, 70, 100, 100);//用线性渐变画刷填充矩形

		GdipDeleteBrush(brush);//销毁画刷
		GdipDeleteBrush(linebrush);//销毁画刷
		GdipDeleteGraphics(graphics);//销毁Graphics对象

		EndPaint(hwnd, &ps);
		return 0;//告诉系统，WM_PAINT消息我已经处理了，你那儿凉快哪儿玩去吧。

效果图：

完整源码：

#include "stdafx.h"
#include <gdiplus.h>
#include <gdiplusflat.h>
#pragma comment(lib,"gdiplus.lib")//very important

#include <windows.h>
#include <windowsx.h>
#pragma comment(lib,"user32.lib")
#pragma comment(lib,"gdi32.lib")

//GDI+Flat
typedef struct _GdiplusStartupInput{
	unsigned int GdiplusVersion;
	unsigned int DebugEventCallback;
	BOOL SuppressBackgroundThread;
	BOOL SuppressExternalCodecs;
}GdiplusStartupInput;

extern "C" int WINAPI GdiplusStartup(int* token, GdiplusStartupInput *input, int *output);
extern "C" void WINAPI GdiplusShutdown(int token);
extern "C" int WINAPI GdipCreateFromHDC(HDC hdc, int* graphics);
extern "C" int WINAPI GdipDeleteGraphics(int graphics);
//画笔
extern "C" int WINAPI GdipCreatePen1(unsigned int argb_color, float width, int unit, int** pen);
extern "C" int WINAPI GdipDeletePen(int* pen);
//画矩形 画直线
extern "C" int WINAPI GdipDrawRectangle(int graphics, int* pen, float x, float y, float width, float height);
extern "C" int WINAPI GdipDrawLine(int graphics, int* pen, float x1, float y1, float x2, float y2);
//画刷
typedef struct _PointF{
	float x;
	float y;
}PointF;
extern "C" int WINAPI GdipCreateSolidFill(unsigned int argb_color, int** brush);
extern "C" int WINAPI GdipCreateLineBrush(PointF* point1, PointF* point2, unsigned int argb_color1, unsigned int argb_color2, int wrapMode, int** lineGradient);
extern "C" int WINAPI GdipDeleteBrush(int* brush);
//画填充矩形
extern "C" int WINAPI GdipFillRectangle(int graphics, int* brush, float x, float y, float width, float height);

int token;
int* pen;
int* brush;
int* linebrush;

//*************************************************************
LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam);

WNDCLASS wc;
const TCHAR* AppName = TEXT("MyWindowClass1");
HWND hwnd1;

int APIENTRY _tWinMain(_In_ HINSTANCE hInstance,
	_In_opt_ HINSTANCE hPrevInstance,
	_In_ LPTSTR    lpCmdLine,
	_In_ int       nCmdShow)
{
	//GDI+开启
	GdiplusStartupInput StartupInput = { 0 };
	StartupInput.GdiplusVersion = 1;
	if (GdiplusStartup(&token, &StartupInput, NULL))MessageBox(0, TEXT("GdiPlus开启失败"), TEXT("错误"), MB_ICONERROR);

	//这里是在构建窗口类结构
	wc.style = CS_HREDRAW | CS_VREDRAW;
	wc.lpfnWndProc = WndProc;//窗口回调函数指针
	wc.cbClsExtra = 0;
	wc.cbWndExtra = 0;
	wc.hInstance = hInstance;//实例句柄
	wc.hIcon = LoadIcon(hInstance, TEXT("ICON_1"));
	wc.hCursor = LoadCursor(NULL, IDC_ARROW);//默认指针
	wc.hbrBackground = (HBRUSH)(COLOR_WINDOW);//默认背景颜色
	wc.lpszMenuName = NULL;
	wc.lpszClassName = AppName;//窗口类名

	//注册窗口类
	if (!RegisterClass(&wc))
	{
		MessageBox(NULL, TEXT("注册窗口类失败!"), TEXT("错误"), MB_ICONERROR);
		return 0;
	}

	//创建窗口
	int style = WS_OVERLAPPEDWINDOW;
	hwnd1 = CreateWindowEx(NULL, AppName, TEXT("窗口标题"), style, 50, 50, 500, 500, 0, LoadMenu(hInstance, TEXT("MENU1")), hInstance, 0);
	if (hwnd1 == NULL)
	{
		MessageBox(NULL, TEXT("创建窗口失败!"), TEXT("错误"), MB_ICONERROR);
		return 0;
	}
	//无边框窗口
	SetWindowLong(hwnd1, GWL_STYLE, WS_OVERLAPPED | WS_VISIBLE | WS_CLIPCHILDREN | WS_CLIPSIBLINGS);

	//显示、更新窗口
	ShowWindow(hwnd1, nCmdShow);
	UpdateWindow(hwnd1);

	//消息循环
	MSG msg;
	while (GetMessage(&msg, NULL, 0, 0))
	{
		TranslateMessage(&msg);
		DispatchMessage(&msg);
	}
	 //GDI+关闭
	GdiplusShutdown(token);//可以把这个写在消息循环后面，程序退出就销毁，或者在不需要GDI+时调用，比如GDI+窗口的WM_DESTROY消息里调用
	return msg.wParam;
}

LRESULT CALLBACK WndProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
	switch (uMsg){

	case WM_PAINT:
		HDC hdc;
		PAINTSTRUCT ps;
		hdc = BeginPaint(hwnd, &ps);

		int graphics;
		GdipCreateFromHDC(hdc, &graphics);//创建Graphics对象
		GdipCreateSolidFill(0x700000FF, &brush);//创建单色画刷
		GdipFillRectangle(graphics, brush, 10, 10, 60, 60);//用单色画刷填充矩形
		PointF p1; p1 = { 70, 0 };
		PointF p2; p2 = { 170, 0 };
		GdipCreateLineBrush(&p1, &p2, 0xFFFF0000, 0x400000FF, 0, &linebrush);//创建线性渐变画刷
		GdipFillRectangle(graphics, linebrush, 70, 70, 100, 100);//用线性渐变画刷填充矩形

		if (0){//这是上一篇中画笔的代码，用if0作废
			GdipCreatePen1(0x60FF2015, 1, 2, &pen);//创建画笔
			GdipDrawRectangle(graphics, pen, 20, 20, 120, 120);//画矩形
			GdipDrawLine(graphics, pen, 50, 60, 170, 340);//画直线
			GdipDeletePen(pen);//销毁画笔
		}

		GdipDeleteBrush(brush);//销毁画刷
		GdipDeleteBrush(linebrush);//销毁画刷
		GdipDeleteGraphics(graphics);//销毁Graphics对象

		EndPaint(hwnd, &ps);
		return 0;//告诉系统，WM_PAINT消息我已经处理了，你那儿凉快哪儿玩去吧。
	case WM_CREATE:
		break;
	case WM_DESTROY://窗口已经销毁
		PostQuitMessage(0);//退出消息循环，结束应用程序
		return 0;
		break;
	case WM_LBUTTONDOWN://鼠标左键按下
		//让无边框窗口能够拖动(在窗口客户区拖动)
		PostMessage(hwnd, WM_SYSCOMMAND, 61458, 0);
		break;
		/*case WM_MOUSEMOVE://鼠标移动
			int xPos, yPos;
			xPos = GET_X_LPARAM(lParam);//鼠标位置X坐标
			yPos = GET_Y_LPARAM(lParam);//鼠标位置Y坐标
			//不要用LOWORD和HIWORD获取坐标，因为坐标有可能是负的
			break;*/
	default:
		break;
	}
	return DefWindowProc(hwnd, uMsg, wParam, lParam);//其他消息交给系统处理
}