用到某处要使用自定义颜色填充图像,貌似Graphics.FillRectangle方法只能用Brush来填充。但是常规Brush都是Brushes定义好的Brush,怎么办呢?
GOOGLE了下有两种方法:
一、用新SolidBrush填充
public void FillByColor(Rectangle rect,Color c,Graphics G)
{
G.FillRectangle(new SolidBrush(c), rect);
}
参考文章:《如何:创建线性渐变》
二、用API实现指定颜色填充一个闭合区域(未测试)
用API实现指定颜色填充
using System.Runtime.InteropServices;
[DllImport("gdi32.dll")]
public static extern IntPtr SelectObject(IntPtr hdc, IntPtr hgdiobj);
[DllImport("gdi32.dll")]
public static extern IntPtr CreateSolidBrush(int crColor);
[DllImport("gdi32.dll")]
public static extern bool ExtFloodFill(IntPtr hdc, int nXStart, int nYStart, int crColor, uint fuFillType);
[DllImport("gdi32.dll")]
public static extern bool DeleteObject(IntPtr hObject);
[DllImport("gdi32.dll")]
public static extern int GetPixel(IntPtr hdc, int x, int y);
public static uint FLOODFILLBORDER = 0;
public static uint FLOODFILLSURFACE = 1;
private void button1_Click(object sender, EventArgs e)
{
Graphics vGraphics = Graphics.FromHwnd(Handle);
vGraphics.DrawRectangle(Pens.Blue, new Rectangle(0, 0, 300, 300));
vGraphics.DrawRectangle(Pens.Blue, new Rectangle(50, 70, 300, 300));
IntPtr vDC = vGraphics.GetHdc();
IntPtr vBrush = CreateSolidBrush(ColorTranslator.ToWin32(Color.Red));
IntPtr vPreviouseBrush = SelectObject(vDC, vBrush);
ExtFloodFill(vDC, 10, 10, GetPixel(vDC, 10, 10), FLOODFILLSURFACE);
SelectObject(vDC, vPreviouseBrush);
DeleteObject(vBrush);
vGraphics.ReleaseHdc(vDC);
}
参考文章:http://www.csharpwin.com/csharpspace/9115r3566.shtml