我会对标题中的实际问题给出一些指示，但我无法弄清楚它是什么。我可以说的是，在我尝试为变量赋值时，表单在实现appbar时不再响应，从而导致我必须停止调试并重新启动计算机以重新获得桌面工作区。错误的位置在下面的代码中注明，我只列出了错误点的代码。在这里有什么明显的明显我没有看到吗？
static class Program
{
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new Form1());
}
}
public partial class Form1 : AppBar
{
public Form1() : base()
{
InitializeComponent();
}
//This is a button on the test form.
//When clicked, the form should become a desktop application bar
//docked to the top of the desktop.
private void t_Click(object sender, EventArgs e)
{
base.SET_APPBAR();
}
}
public class AppBar : Form
{
protected internal Size appbarSize;
protected internal Point appbarLocation;
protected internal bool appbarMode;
private EDGES appbarEdge;
private RECT appbarRect;
private uint ID { get; private set; }
private IntPtr HANDLE { get; private set; }
//constructor
public AppBar() : base () //no issues here
{
appbarEdge = EDGES.ABE_TOP;
appbarRect = new RECT();
ID = 0;
HANDLE = this.Handle;
appbarMode = false;
}
protected internal void SET_APPBAR()
{
if (IS_NEW())
{
QUERY_AND_SET_POSITION(ref appbarRect); //Never get to here
}
}
private bool IS_NEW()
{
if (appbarMode) //so far, so good
{
return false;
}
while (ID == 0)
{
CREATE_ID(); //ID is created, I have verified this.
}
this.FormBorderStyle = FormBorderStyle.FixedToolWindow; //BorderStyle does change
appbarSize = this.Size; //Size is correct
appbarLocation = this.Location; //still no issues
NEW(); //this is where the error begins (see code further down)
return appbarMode; //Never get here
}
private void CREATE_ID()
{
ID = Hooks.RegisterWindowMessage(Guid.NewGuid().ToString());
}
private void QUERY_AND_SET_POSITION(ref RECT appbarRect)
{
SET_APPBAR_SIZE(ref appbarRect);
QUERY_POS(ref appbarRect);
APPBAR_RESIZE(ref appbarRect);
SET_POS(ref appbarRect);
this.Location = new Point(appbarRect.left, appbarRect.top);
appbarSize = new Size(appbarRect.right - appbarRect.left, appbarRect.bottom - appbarRect.top);
this.Size = appbarSize;
}
private void SET_APPBAR_SIZE(ref RECT appbarRect)
{
switch (appbarEdge)
{
case (EDGES.ABE_BOTTOM):
appbarRect.left = 0;
appbarRect.right = SystemInformation.PrimaryMonitorSize.Width;
appbarRect.top = SystemInformation.PrimaryMonitorSize.Height - appbarSize.Height;
appbarRect.bottom = SystemInformation.PrimaryMonitorSize.Height;
break;
case (EDGES.ABE_LEFT):
appbarRect.left = 0;
appbarRect.right = appbarSize.Width;
appbarRect.top = 0;
appbarRect.bottom = SystemInformation.PrimaryMonitorSize.Height;
break;
case (EDGES.ABE_RIGHT):
appbarRect.left = SystemInformation.PrimaryMonitorSize.Width - appbarSize.Width;
appbarRect.right = SystemInformation.PrimaryMonitorSize.Width;
appbarRect.top = 0;
appbarRect.bottom = SystemInformation.PrimaryMonitorSize.Height;
break;
default:
appbarRect.left = 0;
appbarRect.right = SystemInformation.PrimaryMonitorSize.Width;
appbarRect.top = SystemInformation.WorkingArea.Top;
appbarRect.bottom = appbarSize.Height;
break;
}
}
private void APPBAR_RESIZE(ref RECT appbarRect)
{
switch (appbarEdge)
{
case (EDGES.ABE_TOP):
appbarRect.bottom = appbarRect.top + appbarSize.Height;
break;
case (EDGES.ABE_BOTTOM):
appbarRect.top = appbarRect.bottom - appbarSize.Height;
break;
case (EDGES.ABE_LEFT):
appbarRect.right = appbarRect.left + appbarSize.Width;
break;
case (EDGES.ABE_RIGHT):
appbarRect.left = appbarRect.right - appbarSize.Width;
break;
}
}
private void APPBAR_CALLBACK(ref Message apiMessage)
{
switch ((NOTIFICATIONS)(uint)apiMessage.WParam)//? on int vs uint here
{
case (NOTIFICATIONS.ABN_STATECHANGE):
STATE_CHANGE();
break;
case (NOTIFICATIONS.ABN_POSCHANGED):
QUERY_AND_SET_POSITION(ref appbarRect);
break;
case (NOTIFICATIONS.ABN_FULLSCREENAPP):
if ((int)apiMessage.LParam != 0)
{
this.SendToBack();
this.TopMost = false;
}
else
{
STATE_CHANGE();
}
break;
case (NOTIFICATIONS.ABN_WINDOWARRANGE):
//first call
if ((int)apiMessage.LParam != 0)
{
this.Visible = false;
}
//second call
else
{
this.Visible = true;
}
break;
}
}
protected override void WndProc(ref Message apiMessage)
{
if (appbarMode)
{
if (HANDLE == apiMessage.HWnd)
{
APPBAR_CALLBACK(ref apiMessage);
}
else if (apiMessage.Msg == (int)API_MESSAGES.WM_ACTIVATE)
{
ACTIVATE();
}
else if (apiMessage.Msg == (int)API_MESSAGES.WM_WINDOWPOSCHANGED)
{
WINDOW_POS_CHANGED();
}
}
base.WndProc(ref apiMessage);
}
private void NEW()
{
APPBARDATA data = new APPBARDATA(); //no apparent issue
data.cbSize = (uint)Marshal.SizeOf(data); //no apparent issue
data.hWnd = HANDLE; //no apparent issue
data.uCallbackMessage = ID; //no apparent issue
if (Hooks.SHAppBarMessage((uint)DWORD.ABM_NEW, ref data) != 0) //SHAppBar returns 1 (true)
{
//no issue if I were to place a MessageBox here
appbarMode = true; // why in the world is this causing an issue?????
//can't do anything from this point
}
}
}
public static class Hooks
{
[DllImport("shell32.dll", EntryPoint = "SHAppBarMessage")]
public static extern uint SHAppBarMessage(uint dwMessage, ref APPBARDATA pData);
[DllImport("user32.dll", EntryPoint = "RegisterWindowMessage")]
public static extern uint RegisterWindowMessage(
[MarshalAs(UnmanagedType.LPTStr)]
string lpString);
}
发生任何问题后，我都无法点击任何按钮或关闭表单。桌面工作区始终适当调整大小。希望所有这一切都对某人有意义。感谢提前查看。
答案 0 :(得分：3)
问题是您在UI线程中执行长时间运行的操作。这会阻止UI线程并阻止它执行任何其他操作（从绘制更改，响应按钮单击或鼠标移动事件等）。
您需要在后台线程中执行长时间运行的操作。虽然您可以手动执行此操作，但最好使用BackgroundWorker，因为它专为此应用程序而设计。它不仅会为您创建/配置后台线程，而且还提供简单易用的机制，用于在后台任务完成时更新UI，在任务工作时更新UI，等等。
请注意，在后台线程中，您无法访问UI元素;需要从UI线程访问它们。您应该在启动后台任务之前将所有从UI获取信息的代码移动到（稍后将其保存在本地变量或字段中），并且应该移动所有代码以根据结果更新UI（在RunWorkerCompleted事件，如果使用BackgroundWorker）。 DoWork以外的BackgroundWorker以外的所有事件都在UI线程中执行，因此可以访问您的UI控件。