=======================从textbox类继承处理绘制背景消息===================
class mytextbox : textbox
{
const int wm_erasebkgnd = 0x0014;
private image backimage;
[displayname("背景图片。")]
public image backimage
{
get { return backimage; }
set { backimage = value; }
}
protected void onerasebkgnd(graphics gs)
{
gs.fillrectangle(brushes.white, 0, 0, this.width, this.height); //填充为白色，防止图片太小出现重影
if (backimage != null) gs.drawimage(backimage, 0, 0); //绘制背景。
gs.dispose();
}
protected override void wndproc(ref message m)
{
if (m.msg == wm_erasebkgnd) //绘制背景
{
onerasebkgnd(graphics.fromhdc(m.wparam));
m.result = (intptr)1;
}
base.wndproc(ref m);
}
}
==================窗口类里设置控件的字体颜色等============================
const int wm_ctlcoloredit = 0x0133;
const int transparent = 0x1;
const int null_brush = 0x5;
[dllimport("gdi32")]
static extern int setbkmode(intptr hdc, int bkmode);
[dllimport("gdi32")]
static extern int settextcolor(intptr hdc, int color);
[dllimport("gdi32")]
static extern intptr getstockobject(int fnobject);
protected override void wndproc(ref message m)
{
if (m.msg == wm_ctlcoloredit && m.lparam == mytextbox1.handle)//类型为edit(textbox)
{
setbkmode(m.wparam, transparent);//设置背景透明
settextcolor(m.wparam,0xff); //字体颜色为红色
m.result = getstockobject(null_brush);
return;
}
else base.wndproc(ref m);
}
