在VF、VB、PB的应用中,有些无法通过语言工具本身来完成的或者做得不理想的功能,我们会考虑通过Windows的API来完成。
在那个年代,熟悉API是一个编程者的基本功。那个时候网络信息也不发达,很多资料只能考购买书籍或者自己摸索来获取,每次掌握一个新的API应用内心里都有点小激动。
Powerbuilder数据功能强大,但是界面功能尤其是动画功能比较弱,通过调用Windows的API实现窗体动画比较容易。
声明API调用:
function boolean AnimateWindow ( long hwnd, long dwtime, long dwflags ) library "user32"
声明常量:
constant long AW_HOR_POSITIVE = 1
constant long AW_HOR_NEGATIVE = 2
constant long AW_VER_POSITIVE = 4
constant long AW_VER_NEGATIVE = 8
constant long AW_CENTER = 16
constant long AW_HIDE = 65526
constant long AW_ACTIVATE = 131072
conDAT* ? ?stant long AW_SLIDE = 262144
constant long AW_BLEND = 524288
在窗体的open事件中调用:
long ll_handle
ll_handle = Handle ( This )
Randomize ( 0 )
Choose Case rand ( 6 )
Case 1
AnimateWindow ( ll_handle, 1000, AW_SLIDE + AW_VER_POSITIVE + AW_ACTIVATE )
Case 2
AnimateWindow ( ll_handle, 1000, AW_SLIDE + AW_VER_NEGATIVE+ AW_ACTIVATE )
Case 3
AnimateWindow ( ll_handle, 1000, AW_SLIDE + AW_HOR_POSITIVE + AW_ACTIVATE )
Case 4
AnimateWindow ( ll_handle, 1000, AW_SLIDE + AW_HOR_NEGATIVE + AW_ACTIVATE )
Case 6,5
AnimateWindow ( ll_handle, 1000, AW_SLIDE + AW_CENTER + AW_ACTIVATE )
End Choose
在C#中调用Windows的API来实现动画也一样容易。
引用:
using System.Runtime.InteropServices;
定义常量:
public const Int32 AW_HOR_POSITIVE = 0x00000001;
public const Int32 AW_HOR_NEGATIVE = 0x00000002;
public const Int32 AW_VER_POSITIVE = 0x00000004;
public const Int32 AW_VER_NEGATIVE = 0x00000008;
public const Int32 AW_CENTER = 0x00000010;
public const Int32 AW_HIDE = 0x00010000;
public const Int32 AW_ACTIVATE = 0x00020000;
public const Int32 AW_SLIDE = 0x00040000;
public const Int32 AW_BLEND = 0x00080000;
定义调用:
[DllImportAttribute("user32.dll")]
private static extern bool AnimateWindow(IntPtr hwnd,int dwTime,int dwFlags);
调用:
private void Form1_Load(object sender, EventArgs e)
{
//this.FormBorderStyle =0 ;
Random rand = new Random();
long LL = rand.Next(1,6);
label1.Text = "动画演示:"+LL.ToString();
switch (LL)
{
case 1:
AnimateWindow(this.Handle, 1000, AW_SLIDE + AW_VER_POSITIVE + AW_ACTIVATE);
break;
case 2:
AnimateWindow(this.Handle, 1000, AW_SLIDE + AW_VER_NEGATIVE + AW_ACTIVATE);
break;
case 3:
AnimateWindow(this.Handle, 1000, AW_SLIDE + AW_HOR_POSITIVE + AW_ACTIVATE);
break;
case 4:
AnimateWindow(this.Handle, 1000, AW_SLIDE + AW_HOR_NEGATIVE + AW_ACTIVATE);
break;
case 5:
AnimateWindow(this.Handle, 1000, AW_SLIDE + AW_CENTER + AW_ACTIVATE);
break;
case 6:
AnimateWindow(this.Handle, 1000, AW_SLIDE + AW_CENTER + AW_ACTIVATE);
break;
}
}
效果图
