前阵子写了个UserControl, 需要处理Arrow keys.( Up, Down, Left, Right). 但是这四个键属于DialogKey，有两种解决方案可以使得UserControl在OnKeyDown中处理这四个键。
方案一：
重载ProcessDialogKey。
protected override bool ProcessDialogKey(Keys keyData)
{
if (keyData == Keys.Up || keyData == Keys.Down
|| keyData == Keys.Left || keyData == Keys.Right)
return false;
else
return base.ProcessDialogKey(keyData);
}
方案二：
重载ProcessKeyPreview，强制加上Key消息事件分发的逻辑；然后重载IsInputKey。
protected override bool ProcessKeyPreview(ref Message m)
{
if (base.ProcessKeyEventArgs(ref m))
{
return true;
}
return base.ProcessKeyPreview (ref m);
}
protected override bool IsInputKey(Keys keyData)
{
if ( this.Focused )
{
Keys keys1 = (keyData & Keys.KeyCode);
switch (keys1)
{
case Keys.Up:
case Keys.Down:
case Keys.Left:
case Keys.Right:
{
return true;
}
}
}
return base.IsInputKey(keyData);
}
