Question

.net如何实现（当以运行软件 就自动打开自己电脑上的摄像头）

程序一运行 就 打开本机的摄像头
IntPtr hWndC, string path ;hWndC 传什么参数进去 ，path 是传物理保存图片路径 ；我怎么调用啊

Answer 1

public class VideoAPI //视频API类
{
// 视频API调用
[DllImport("avicap32.dll")]
public static extern IntPtr capCreateCaptureWindowA(byte[] lpszWindowName, int dwStyle, int x, int y, int nWidth, int nHeight, IntPtr hWndParent, int nID);
[DllImport("avicap32.dll")]
public static extern bool capGetDriverDescriptionA(short wDriver, byte[] lpszName, int cbName, byte[] lpszVer, int cbVer);
[DllImport("User32.dll")]
public static extern bool SendMessage(IntPtr hWnd, int wMsg, bool wParam, int lParam);
[DllImport("User32.dll")]
public static extern bool SendMessage(IntPtr hWnd, int wMsg, short wParam, int lParam);

// 常量
public const int WM_USER = 0x400;
public const int WS_CHILD = 0x40000000;
public const int WS_VISIBLE = 0x10000000;
public const int SWP_NOMOVE = 0x2;
public const int SWP_NOZORDER = 0x4;
public const int WM_CAP_DRIVER_CONNECT = WM_USER + 10;
public const int WM_CAP_DRIVER_DISCONNECT = WM_USER + 11;
public const int WM_CAP_SET_CALLBACK_FRAME = WM_USER + 5;
public const int WM_CAP_SET_PREVIEW = WM_USER + 50;
public const int WM_CAP_SET_PREVIEWRATE = WM_USER + 52;
public const int WM_CAP_SET_VIDEOFORMAT = WM_USER + 45;
public const int WM_CAP_START = WM_USER;
public const int WM_CAP_SAVEDIB = WM_CAP_START + 25;
}

public class cVideo //视频类
{
private IntPtr lwndC; //保存无符号句柄
private IntPtr mControlPtr; //保存管理指示器
private int mWidth;
private int mHeight;

public cVideo(IntPtr handle, int width, int height)
{
mControlPtr = handle; //显示视频控件的句柄
mWidth = width; //视频宽度
mHeight = height; //视频高度
}
/// <summary>
/// 打开视频设备
/// </summary>
public void StartWebCam()
{
byte[] lpszName = new byte[100];
byte[] lpszVer = new byte[100];

VideoAPI.capGetDriverDescriptionA(0, lpszName, 100, lpszVer, 100);
this.lwndC = VideoAPI.capCreateCaptureWindowA(lpszName, VideoAPI.WS_CHILD | VideoAPI.WS_VISIBLE, 0, 0, mWidth, mHeight, mControlPtr, 0);

if (VideoAPI.SendMessage(lwndC, VideoAPI.WM_CAP_DRIVER_CONNECT, 0, 0))
{
VideoAPI.SendMessage(lwndC, VideoAPI.WM_CAP_SET_PREVIEWRATE, 100, 0);
VideoAPI.SendMessage(lwndC, VideoAPI.WM_CAP_SET_PREVIEW, true, 0);
}
}
/// <summary>
/// 关闭视频设备
/// </summary>
public void CloseWebcam()
{
VideoAPI.SendMessage(lwndC, VideoAPI.WM_CAP_DRIVER_DISCONNECT, 0, 0);
}

/// <summary>
/// 拍照
/// </summary>
/// <param name="path">要保存bmp文件的路径</param>
public void GrabImage(IntPtr hWndC, string path)
{
IntPtr hBmp = Marshal.StringToHGlobalAnsi(path);
VideoAPI.SendMessage(lwndC, VideoAPI.WM_CAP_SAVEDIB, 0, hBmp.ToInt32());
}
}

Answer 2

1、通过iTunes 恢复固件会导致清空iOS设备上所有的资料，建议先备份好重要资料。
　　2、已经越狱iPhone \ iPad \ iTouch使用iTunes升级 \ 恢复会可能报未知错误，请放心!iPhone \ iPad \ iTouch升级 \ 恢复失败会自动进入恢复模式，请连接iTunes 再恢复iOS8固件一次就可以。
　　3、如果你没有越狱，可以通过OTA升级至iOS8.3
　　1. 打开PP助手电脑版(下载)，根据机型下载好上面所对应的固件版本。
　　
　　2. 将iPhone \ iPad \ iTouch 连接电脑打开iTunes
　　
　　3. 按住键盘上Shift(上档键)+鼠标左键点击iTunes 的更新 \ 恢复功能
　　
　　4.iTunes会弹出对话窗--请选择已经下载好的固件--点击更新--等待iTunes运行。
　　
　　5. 成功升级 \ 恢复iOS8后需要先激活设备才可以正常使用!(请系统提示步骤完成)

Answer 3

public class VideoAPI //视频API类
{
// 视频API调用
[DllImport("avicap32.dll")]
public static extern IntPtr capCreateCaptureWindowA(byte[] lpszWindowName, int dwStyle, int x, int y, int nWidth, int nHeight, IntPtr hWndParent, int nID);
[DllImport("avicap32.dll")]
public static extern bool capGetDriverDescriptionA(short wDriver, byte[] lpszName, int cbName, byte[] lpszVer, int cbVer);
[DllImport("User32.dll")]
public static extern bool SendMessage(IntPtr hWnd, int wMsg, bool wParam, int lParam);
[DllImport("User32.dll")]
public static extern bool SendMessage(IntPtr hWnd, int wMsg, short wParam, int lParam);

// 常量
public const int WM_USER = 0x400;
public const int WS_CHILD = 0x40000000;
public const int WS_VISIBLE = 0x10000000;
public const int SWP_NOMOVE = 0x2;
public const int SWP_NOZORDER = 0x4;
public const int WM_CAP_DRIVER_CONNECT = WM_USER + 10;
public const int WM_CAP_DRIVER_DISCONNECT = WM_USER + 11;
public const int WM_CAP_SET_CALLBACK_FRAME = WM_USER + 5;
public const int WM_CAP_SET_PREVIEW = WM_USER + 50;
public const int WM_CAP_SET_PREVIEWRATE = WM_USER + 52;
public const int WM_CAP_SET_VIDEOFORMAT = WM_USER + 45;
public const int WM_CAP_START = WM_USER;
public const int WM_CAP_SAVEDIB = WM_CAP_START + 25;
}

public class cVideo //视频类
{
private IntPtr lwndC; //保存无符号句柄
private IntPtr mControlPtr; //保存管理指示器
private int mWidth;
private int mHeight;

public cVideo(IntPtr handle, int width, int height)
{
mControlPtr = handle; //显示视频控件的句柄
mWidth = width; //视频宽度
mHeight = height; //视频高度
}
/// <summary>
/// 打开视频设备
/// </summary>
public void StartWebCam()
{
byte[] lpszName = new byte[100];
byte[] lpszVer = new byte[100];

VideoAPI.capGetDriverDescriptionA(0, lpszName, 100, lpszVer, 100);
this.lwndC = VideoAPI.capCreateCaptureWindowA(lpszName, VideoAPI.WS_CHILD | VideoAPI.WS_VISIBLE, 0, 0, mWidth, mHeight, mControlPtr, 0);

if (VideoAPI.SendMessage(lwndC, VideoAPI.WM_CAP_DRIVER_CONNECT, 0, 0))
{
VideoAPI.SendMessage(lwndC, VideoAPI.WM_CAP_SET_PREVIEWRATE, 100, 0);
VideoAPI.SendMessage(lwndC, VideoAPI.WM_CAP_SET_PREVIEW, true, 0);
}
}
/// <summary>
/// 关闭视频设备
/// </summary>
public void CloseWebcam()
{
VideoAPI.SendMessage(lwndC, VideoAPI.WM_CAP_DRIVER_DISCONNECT, 0, 0);
}

/// <summary>
/// 拍照
/// </summary>
/// <param name="path">要保存bmp文件的路径</param>
public void GrabImage(IntPtr hWndC, string path)
{
IntPtr hBmp = Marshal.StringToHGlobalAnsi(path);
VideoAPI.SendMessage(lwndC, VideoAPI.WM_CAP_SAVEDIB, 0, hBmp.ToInt32());
}
}

Answer 4

使用API函数
[DllImport("avicap32.dll")]
capCreateCaptureWindowA
这个可以启动摄像头，至于自动打开的问题，那就看你怎么用程序控制了。

Answer 5

1. 使用API函数

2. [DllImport("avicap32.dll")]

   capCreateCaptureWindowA

3. 这个可以启动摄像头，至于自动打开的问题，那就看你怎么用程序控制了。