/// <include file='doc\CommonDialog.uex' path='docs/doc[@for="CommonDialog.ShowDialog1"]/*' />
/// <devdoc>
/// <para>
/// Runs a common dialog box, parented to the given IWin32Window.
/// </para>
/// </devdoc>
public DialogResult ShowDialog(IWin32Window owner)
{
IntSecurity.SafeSubWindows.Demand();
if (owner == null || owner.Handle == IntPtr.Zero)
{
return(ShowDialog());
}
if (!SystemInformation.UserInteractive)
{
throw new InvalidOperationException(SR.GetString(SR.CantShowModalOnNonInteractive));
}
if (helpMsg == 0)
{
helpMsg = SafeNativeMethods.RegisterWindowMessage("commdlg_help");
}
IntPtr hwndOwner = owner.Handle;
defOwnerWndProc = UnsafeNativeMethods.GetWindowLong(new HandleRef(owner, hwndOwner), NativeMethods.GWL_WNDPROC);
// define ownerproc out here so it won't be garbage collected before the finally
// clause runs
NativeMethods.WndProc ownerProc = new NativeMethods.WndProc(this.OwnerWndProc);
DialogResult result = DialogResult.Cancel;
try {
UnsafeNativeMethods.SetWindowLong(new HandleRef(owner, hwndOwner), NativeMethods.GWL_WNDPROC, ownerProc);
Application.BeginModalMessageLoop();
try {
result = RunDialog(hwndOwner) ? DialogResult.OK : DialogResult.Cancel;
GC.KeepAlive(ownerProc);
}
finally {
Application.EndModalMessageLoop();
}
}
finally {
if (UnsafeNativeMethods.IsWindow(new HandleRef(owner, hwndOwner)))
{
UnsafeNativeMethods.SetWindowLong(new HandleRef(owner, hwndOwner), NativeMethods.GWL_WNDPROC, new HandleRef(null, defOwnerWndProc));
}
}
return(result);
}
public DialogResult ShowDialog(IWin32Window owner)
{
if (!SystemInformation.UserInteractive)
{
throw new InvalidOperationException(SR.CantShowModalOnNonInteractive);
}
NativeWindow native = null;//This will be used if there is no owner or active window (declared here so it can be kept alive)
IntPtr hwndOwner = IntPtr.Zero;
DialogResult result = DialogResult.Cancel;
try {
if (owner != null)
{
hwndOwner = Control.GetSafeHandle(owner);
}
if (hwndOwner == IntPtr.Zero)
{
hwndOwner = UnsafeNativeMethods.GetActiveWindow();
}
if (hwndOwner == IntPtr.Zero)
{
//We will have to create our own Window
native = new NativeWindow();
native.CreateHandle(new CreateParams());
hwndOwner = native.Handle;
}
if (helpMsg == 0)
{
helpMsg = SafeNativeMethods.RegisterWindowMessage("commdlg_help");
}
NativeMethods.WndProc ownerProc = new NativeMethods.WndProc(this.OwnerWndProc);
hookedWndProc = System.Runtime.InteropServices.Marshal.GetFunctionPointerForDelegate(ownerProc);
System.Diagnostics.Debug.Assert(IntPtr.Zero == defOwnerWndProc, "The previous subclass wasn't properly cleaned up");
IntPtr userCookie = IntPtr.Zero;
try {
//UnsafeNativeMethods.[Get|Set]WindowLong is smart enough to call SetWindowLongPtr on 64-bit OS
defOwnerWndProc = UnsafeNativeMethods.SetWindowLong(new HandleRef(this, hwndOwner), NativeMethods.GWL_WNDPROC, ownerProc);
if (Application.UseVisualStyles)
{
userCookie = UnsafeNativeMethods.ThemingScope.Activate();
}
Application.BeginModalMessageLoop();
try {
result = RunDialog(hwndOwner) ? DialogResult.OK : DialogResult.Cancel;
}
finally {
Application.EndModalMessageLoop();
}
}
finally {
IntPtr currentSubClass = UnsafeNativeMethods.GetWindowLong(new HandleRef(this, hwndOwner), NativeMethods.GWL_WNDPROC);
if (IntPtr.Zero != defOwnerWndProc || currentSubClass != hookedWndProc)
{
UnsafeNativeMethods.SetWindowLong(new HandleRef(this, hwndOwner), NativeMethods.GWL_WNDPROC, new HandleRef(this, defOwnerWndProc));
}
UnsafeNativeMethods.ThemingScope.Deactivate(userCookie);
defOwnerWndProc = IntPtr.Zero;
hookedWndProc = IntPtr.Zero;
//Ensure that the subclass delegate will not be GC collected until after it has been subclassed
GC.KeepAlive(ownerProc);
}
}
finally {
if (null != native)
{
native.DestroyHandle();
}
}
return(result);
}
