Question

VB做一个图片浏览器，浏览器有个功能是设置桌面背景，请问怎么些代码？

Answer 1

以下代码可以达到你的要求:
(可以定时更换墙纸)

Private Sub Timer1_Timer() '一分钟循环一次
Dim FileName As String
Dim Ret As Long
Dim MyValue As Integer

If ListFile.ListCount > 0 And (TimeCount Mod TimeValue) = 0 Then '更换为选定的墙纸

If Option1.Value = True Then '顺序更换
If FileNum > ListFile.ListCount Then FileNum = 1
FileName = ListFile.List(FileNum - 1)
FileNum = FileNum + 1
ElseIf Option2.Value = True Then '随机更换
Randomize ' 对随机数生成器做初始化的动作
MyValue = Int(ListFile.ListCount * Rnd) ' 生成 0 到 LISTBOX中数目和(ListCount-1个)之间的随机数值。
FileName = ListFile.List(MyValue)
End If

If fs.FileExists(FileName) Then '文件是否存在
If Option3.Value = True Then '平铺
rc = RegOpenKeyEx(HKEY_CURRENT_USER, gREGKEYWallPaper, 0, KEY_ALL_ACCESS, hKey) '打开相应注册键值
rc = RegSetValueEx(hKey, "TileWallpaper", 0, REG_SZ, ByVal "1", 2) '写入相应键值信息
rc = RegSetValueEx(hKey, "WallpaperStyle", 0, REG_SZ, ByVal "0", 2) '写入相应键值信息

Ret = WritePrivateProfileString("Desktop", "Wallpaper", FileName, "Win.ini") '更换结果写入到Win.ini中相应相置
Ret = WritePrivateProfileString("Desktop", "TileWallpaper", "1", "Win.ini") '更换结果写入到Win.ini中相应相置
Ret = WritePrivateProfileString("Desktop", "WallpaperStyle", "0", "Win.ini") '更换结果写入到Win.ini中相应相置

Ret = SystemParametersInfo(SPI_SETDESKWALLPAPER, 0&, ByVal FileName, SPIF_UPDATEINIFILE) '更新系统参数信息
ElseIf Option4.Value = True Then '拉伸
rc = RegOpenKeyEx(HKEY_CURRENT_USER, gREGKEYWallPaper, 0, KEY_ALL_ACCESS, hKey) '打开相应注册键值
rc = RegSetValueEx(hKey, "TileWallpaper", 0, REG_SZ, ByVal "0", 2) '写入相应键值信息
rc = RegSetValueEx(hKey, "WallpaperStyle", 0, REG_SZ, ByVal "2", 2) '写入相应键值信息

Ret = WritePrivateProfileString("Desktop", "Wallpaper", FileName, "Win.ini") '更换结果写入到Win.ini中相应相置
Ret = WritePrivateProfileString("Desktop", "TileWallpaper", "0", "Win.ini") '更换结果写入到Win.ini中相应相置
Ret = WritePrivateProfileString("Desktop", "WallpaperStyle", "2", "Win.ini") '更换结果写入到Win.ini中相应相置

Ret = SystemParametersInfo(SPI_SETDESKWALLPAPER, 0&, ByVal FileName, SPIF_UPDATEINIFILE) '更新系统参数信息
ElseIf Option5.Value = True Then '居中
rc = RegOpenKeyEx(HKEY_CURRENT_USER, gREGKEYWallPaper, 0, KEY_ALL_ACCESS, hKey) '打开相应注册键值
rc = RegSetValueEx(hKey, "TileWallpaper", 0, REG_SZ, ByVal "0", 2) '写入相应键值信息
rc = RegSetValueEx(hKey, "WallpaperStyle", 0, REG_SZ, ByVal "0", 2) '写入相应键值信息

Ret = WritePrivateProfileString("Desktop", "Wallpaper", FileName, "Win.ini") '更换结果写入到Win.ini中相应相置
Ret = WritePrivateProfileString("Desktop", "TileWallpaper", "0", "Win.ini") '更换结果写入到Win.ini中相应相置
Ret = WritePrivateProfileString("Desktop", "WallpaperStyle", "0", "Win.ini") '更换结果写入到Win.ini中相应相置

Ret = SystemParametersInfo(SPI_SETDESKWALLPAPER, 0&, ByVal FileName, SPIF_UPDATEINIFILE) '更新系统参数信息
End If
End If

End If

TimeCount = TimeCount + 1 '因为计数器时间间隔不能大于65535毫秒，故采取此计数法

End Sub