private static void SetCompositionWindow(HwndSource source, IntPtr hIMC, FrameworkElement textArea)
{
if (textArea == null)
{
throw new ArgumentNullException(nameof(textArea));
}
var textViewBounds = new Rect(16, 100, 20, 40); // ImeHelper.GetBounds(textArea, source);
var characterBounds = new Rect(16, 200, 20, 40); // textArea.DocumentManager.CaretInfo.Bounds;
characterBounds = textArea.TransformToAncestor(source.RootVisual).TransformBounds(characterBounds);
//解决surface上输入法光标位置不正确
//现象是surface上光标的位置需要乘以2才能正确，普通电脑上没有这个问题
//且此问题与DPI无关，目前用CaretWidth可以有效判断
var caretLeftTop = new Point(characterBounds.TopLeft.X / SystemParameters.CaretWidth,
characterBounds.TopLeft.Y / SystemParameters.CaretWidth);
const int CFS_DEFAULT = 0x0000;
const int CFS_RECT = 0x0001;
const int CFS_POINT = 0x0002;
const int CFS_FORCE_POSITION = 0x0020;
const int CFS_EXCLUDE = 0x0080;
const int CFS_CANDIDATEPOS = 0x0040;
var form = new ImeNative.CompositionForm();
form.dwStyle = CFS_POINT;
form.ptCurrentPos.x = (int)Math.Max(caretLeftTop.X, textViewBounds.Left);
form.ptCurrentPos.y = (int)Math.Max(caretLeftTop.Y, textViewBounds.Top);
form.ptCurrentPos.y += (int)characterBounds.Height;
ImeNative.ImmSetCompositionWindow(hIMC, ref form);
}
private static void SetCompositionFont(HwndSource source, IntPtr hIMC, FrameworkElement textArea)
{
if (textArea == null)
{
throw new ArgumentNullException(nameof(textArea));
}
var lf = new ImeNative.LOGFONT();
var characterBounds = new Rect(16, 200, 20, 40); // textArea.DocumentManager.CaretInfo.Bounds;
lf.lfFaceName = "Microsoft YaHei";
lf.lfHeight = (int)characterBounds.Height;
var GCS_COMPSTR = 8;
var length = ImeNative.ImmGetCompositionString(hIMC, GCS_COMPSTR, null, 0);
if (length > 0)
{
var target = new byte[length];
var count = ImeNative.ImmGetCompositionString(hIMC, GCS_COMPSTR, target, length);
if (count > 0)
{
var inputString = Encoding.Default.GetString(target);
if (string.IsNullOrWhiteSpace(inputString))
{
lf.lfWidth = 1;
}
}
}
ImeNative.ImmSetCompositionFont(hIMC, ref lf);
}
private void ClearContext()
{
if (_hwndSource == null)
{
return;
}
ImeNative.ImmAssociateContext(_hwndSource.Handle, _previousContext);
ImeNative.ImmReleaseContext(_defaultImeWnd, _currentContext);
_currentContext = IntPtr.Zero;
_defaultImeWnd = IntPtr.Zero;
_hwndSource.RemoveHook(WndProc);
_hwndSource = null;
}
private void CreateContext()
{
_hwndSource = (HwndSource)PresentationSource.FromVisual(_textArea);
if (_hwndSource == null)
{
return;
}
_defaultImeWnd = ImeNative.ImmGetDefaultIMEWnd(IntPtr.Zero);
_currentContext = ImeNative.ImmGetContext(_defaultImeWnd);
_previousContext = ImeNative.ImmAssociateContext(_hwndSource.Handle, _currentContext);
_hwndSource.AddHook(WndProc);
//尽管文档说传递null是无效的，但这似乎有助于在与WPF共享的默认输入上下文中激活IME
var threadMgr = ImeNative.GetTextFrameworkThreadManager();
threadMgr?.SetFocus(IntPtr.Zero);
}
/// <summary>
/// 构造一个IME支持对象，传入需要支持IME的控件即可
/// </summary>
/// <param name="textArea"></param>
public ImeSupport(FrameworkElement textArea)
{
_textArea = textArea ?? throw new ArgumentNullException(nameof(textArea));
_textArea.GotKeyboardFocus += (s, e) =>
{
if (_textArea.IsKeyboardFocused)
{
if (_hwndSource != null)
{
return;
}
_isUpdatingCompositionWindow = true;
ClearContext();
CreateContext();
}
else
{
ClearContext();
return;
}
UpdateCompositionWindow();
_isUpdatingCompositionWindow = false;
};
_textArea.LostKeyboardFocus += (s, e) =>
{
if (_isUpdatingCompositionWindow)
{
return;
}
if (Equals(e.OldFocus, _textArea) && _currentContext != IntPtr.Zero)
{
ImeNative.ImmNotifyIME(_currentContext, ImeNative.NI_COMPOSITIONSTR, ImeNative.CPS_CANCEL);
}
ClearContext();
};
InputMethod.SetIsInputMethodSuspended(_textArea, true);
}
