C#扩展WebBrowser控件，使其支持拖放文件

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2021年2月8日 17:7 本文热度 3156

public partial class UserControl1 : WebBrowser

{

    private const int WmDropfiles = 0x233;

    [DllImport("shell32.dll")]

    private static extern uint DragQueryFile(IntPtr hDrop, uint iFile, StringBuilder lpszFile, uint cch);

    [DllImport("shell32.dll")]

    private static extern void DragAcceptFiles(IntPtr hWnd, bool fAccept);

    protected override void OnHandleCreated(EventArgs e)

{

        base.OnHandleCreated(e);

        //指示接受文件拖放操作

        if (!DesignMode)

{

            DragAcceptFiles(Handle, true);

}

}

    protected override void WndProc(ref Message m)

{

        if (m.Msg == WmDropfiles)

{

            #region 解析消息

            //获取拖放的文件数量

            var count = DragQueryFile(m.WParam, 0xffffffff, null, 0);

            //解析所有播放的文件路径

            var filePaths = new string[count];

            for (uint i = 0; i < count; i++)

{

                var sb = new StringBuilder();

                DragQueryFile(m.WParam, i, sb, 1024);

                filePaths[i] = sb.ToString();

}

            #endregion

            //是否继续触发之后的消息处理

            var isCancel = false;

            #region 触发自定义文件拖放事件

            if (DragFile != null)

{

                var args = new DragFileEventArgs(filePaths);

                DragFile(this, args);

                isCancel = args.IsCancel;

}

            #endregion

            if (isCancel) return;

}

        base.WndProc(ref m);

}

    public event EventHandler<DragFileEventArgs> DragFile;

    public class DragFileEventArgs : EventArgs

{

        private readonly string[] _filePaths;

        public bool IsCancel { get; set; }

        public DragFileEventArgs(string[] filePaths)

{

            _filePaths = filePaths;

}

        public string[] FilePaths

{

            get { return _filePaths; }

}

}

}

该文章在 2021/2/8 17:07:23 编辑过

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