根据一副png图片绘制半透明窗体时，用了WS_EX_LAYERED后当前窗体再也不会处理paint事件，所以所含的子控件是一辈子也不会画出来的，但是这个控件确实存在，而且可以响应事件 。而此时windows画制窗体是使用UpdateLayeredWindow这个api函数的。
其实这个问题，3年前就在csdn网友miky的"笨笨钟"发布后就讨论过了，后来出了一个叫桌面天气秀
的东东也采用类似的技术。那时候我有幸拿到了miky的delphi下实现gdi+半透明窗体的一段代码，因为无法画出button等控件和
几位高人讨论过，这里是当时的讨论情况
http://borland.mblogger.cn/jinjazz/posts/21093.aspx
最终并没有很好的解决办法，而是通过大概如下的方法解决的
————————————————————————————————————
对于按钮，完全可以自己画两个图片然后盖在button上面，通过处理button的enter和leave消息来切换者两个图片来表达按钮状态
对于输入框..这个可以用一个让任何人看了都生气地办法，那就是....两个窗体
，的确别人就是这么做的
可以用一个空心窗体只显示该显示的控件，然后盖在你的半透明窗体上面，并处理半透明窗体的move事件，让另外一个窗体同步移动或者做其它事情
效果如下：
以下是一些C#代码，Delphi的就不贴了
主Form的代码
usingSystem;
using
System.Drawing;
using
System.Drawing.Imaging;
using
System.Collections;
using
System.ComponentModel;
using
System.Windows.Forms;
using
System.Data;
using
System.Runtime.InteropServices;
namespace
WindowsApplication7
...
{
public
class
Form1 : System.Windows.Forms.Form
...
{
private
System.ComponentModel.IContainer components;
public
Form1()
...
{
//
//
Windows 窗体设计器支持所必需的
//
InitializeComponent();
FormBorderStyle
=
FormBorderStyle.None;
}
/**/
///
<summary>
///
清理所有正在使用的资源。
///
</summary>
protected
override
void
Dispose(
bool
disposing )
...
{
if
( disposing )
...
{
if
(components
!=
null
)
...
{
components.Dispose();
}
}
base
.Dispose( disposing );
}
Windows Form Designer generated code
#region
Windows Form Designer generated code
/**/
///
<summary>
///
设计器支持所需的方法 - 不要使用代码编辑器修改
///
此方法的内容。
///
</summary>
private
void
InitializeComponent()
...
{
this
.button1
=
new
System.Windows.Forms.Button();
this
.SuspendLayout();
//
//
button1
//
this
.button1.Cursor
=
System.Windows.Forms.Cursors.Hand;
this
.button1.Location
=
new
System.Drawing.Point(
20
,
20
);
this
.button1.Name
=
"
button1
"
;
this
.button1.Size
=
new
System.Drawing.Size(
113
,
51
);
this
.button1.TabIndex
=
1
;
this
.button1.Text
=
"
button1
"
;
this
.button1.MouseLeave
+=
new
System.EventHandler(
this
.button1_MouseLeave);
this
.button1.Click
+=
new
System.EventHandler(
this
.button1_Click);
this
.button1.MouseEnter
+=
new
System.EventHandler(
this
.button1_MouseEnter);
//
//
Form1
//
this
.AutoScaleBaseSize
=
new
System.Drawing.Size(
6
,
14
);
this
.ClientSize
=
new
System.Drawing.Size(
184
,
123
);
this
.Controls.Add(
this
.button1);
this
.Name
=
"
Form1
"
;
this
.StartPosition
=
System.Windows.Forms.FormStartPosition.CenterScreen;
this
.Text
=
"
Form1
"
;
this
.Load
+=
new
System.EventHandler(
this
.Form1_Load);
this
.VisibleChanged
+=
new
System.EventHandler(
this
.Form1_VisibleChanged);
this
.FormClosed
+=
new
System.Windows.Forms.FormClosedEventHandler(
this
.Form1_FormClosed);
this
.MouseDown
+=
new
System.Windows.Forms.MouseEventHandler(
this
.Form1_MouseDown);
this
.Move
+=
new
System.EventHandler(
this
.Form1_Move);
this
.ResumeLayout(
false
);
}
#endregion
/**/
///
<summary>
///
应用程序的主入口点。
///
</summary>
[STAThread]static
void
Main()
...
{
Application.Run(
new
Form1());
}
Form2 controlFrm
=
new
Form2();
private
void
button1_Click(
object
sender, System.EventArgs e)
...
{
MessageBox.Show(controlFrm,controlFrm.textBox1.Text);
}
protected
override
CreateParams CreateParams
...
{
get
...
{
CreateParams cp
=
base
.CreateParams;
cp.ExStyle
|=
0x00080000
;
//
This form has to have the WS_EX_LAYERED extended style
return
cp;
}
}
private
void
SetStyle1()
...
{
Bitmap bm
=
Image.FromFile(
@"
Green.png
"
)
as
Bitmap;
Bitmap bm2
=
Image.FromFile(
@"
btn.png
"
)
as
Bitmap;
Graphics g
=
Graphics.FromImage(bm);
g.DrawImage(bm2,
20
,
20
,
new
Rectangle(
0
,
0
,
90
,
50
), GraphicsUnit.Pixel);
g.DrawString(
"
by jinjazz
"
,
new
Font(
"
Ariel
"
,
9
, FontStyle.Bold),
new
SolidBrush(Color.Black),
new
PointF(
40
,
50
));
this
.SetBitmap(bm,
255
);
}
private
void
SetStyle2()
...
{
Bitmap bm
=
Image.FromFile(
@"
Green.png
"
)
as
Bitmap;
Bitmap bm2
=
Image.FromFile(
@"
btn.png
"
)
as
Bitmap;
Graphics g
=
Graphics.FromImage(bm);
g.DrawImage(bm2,
15
,
15
,
new
Rectangle(
7
,
140
,
100
,
50
), GraphicsUnit.Pixel);
g.DrawString(
"
by jinjazz
"
,
new
Font(
"
Ariel
"
,
9
, FontStyle.Bold),
new
SolidBrush(Color.Black),
new
PointF(
40
,
50
));
this
.SetBitmap(bm,
255
);
}
private
void
Form1_Load(
object
sender, System.EventArgs e)
...
{
controlFrm.Show();
SetStyle1();
//
this.TopMost = true;
controlFrm.TopMost
=
true
;
}
private
void
button1_MouseEnter(
object
sender, EventArgs e)
...
{
SetStyle2();
}
private
void
button1_MouseLeave(
object
sender, EventArgs e)
...
{
SetStyle1();
}
public
void
SetBitmap(Bitmap bitmap,
byte
opacity)
.