我正在努力将插入符号移动到DataGridView 中的文本框编辑控件中，一行向上，一行向下，就像用户在按向上和向下箭头时所得到的那样。
所以我的意思不是换行符之间的行，我的意思是文本框左右两边的行。
我无法使用GetCharIndexFromPosition和GetPositionFromCharIndex，因为并非所有文本都会始终显示在文本框显示区域中。
修改 我无法模拟KeyPress，因为我正在处理DataGridView中的文本框单元格。我的目标实际上是让箭头键在普通文本框中执行操作，而不是从一行到另一行跳转。
答案 0 :(得分：1)
这应该有用。
Point pOld = textBox1.GetPositionFromCharIndex(textBox1.SelectionStart);
Point pNew = new Point(pOld.X, pOld.Y + textBox1.Font.Height)
int charIndex = textBox1.GetCharIndexFromPosition(pNew);
textBox1.SelectionStart = charIndex;
我认为这不是最干净的解决方案。也许您应该查看DataGridView属性/键处理。
答案 1 :(得分：1)
方法GetPositionFromCharIndex()和GetCharIndexFromPosition()有两个限制：
TextBox.SelectionStart的字符索引对于行尾的插入符号和下一行开头的插入符号相同。要纠正此问题，您可以：
我遇到的另一个问题是TextBox.Lines指的是由换行符分隔的逻辑行，而函数TextBox.GetLineFromCharIndex()和TextBox.GetFirstCharIndexFromLine()指的是在文本框中显示的可视线（也就是说，从TextBox的一边到另一边，没有必须是新行字符）。不要混淆它们。
结果代码（您可能声称的丑陋，但正在工作）如下：
class Utils
{
[DllImport("user32.dll")]
static extern bool GetCaretPos(out System.Drawing.Point lpPoint);
public static void LineUp(TextBox tb)
{
int oldCharIndex = tb.SelectionStart;
int oldLineNo = tb.GetLineFromCharIndex(oldCharIndex);
System.Drawing.Point oldCharPos = tb.GetPositionFromCharIndex(oldCharIndex);
System.Drawing.Point oldCaretPos;
if (GetCaretPos(out oldCaretPos))
{
if (oldCharPos == oldCaretPos)
{
if (oldLineNo > 0)
{
tb.SelectionStart = tb.GetFirstCharIndexFromLine(oldLineNo - 1);
tb.ScrollToCaret();
System.Drawing.Point newPos = new System.Drawing.Point(oldCaretPos.X, oldCaretPos.Y - tb.Font.Height);
int newCharIndex = tb.GetCharIndexFromPosition(newPos);
if (tb.GetPositionFromCharIndex(newCharIndex).Y == newPos.Y)
{
tb.SelectionStart = newCharIndex;
}
else
{
tb.SelectionStart = tb.GetFirstCharIndexFromLine(oldLineNo - 1);
System.Windows.Forms.SendKeys.Send("{END}");
}
}
}
else
{
if (oldLineNo > 1)
{
tb.SelectionStart = tb.GetFirstCharIndexFromLine(oldLineNo - 2);
tb.ScrollToCaret();
System.Drawing.Point newPos = new System.Drawing.Point(oldCaretPos.X, oldCaretPos.Y - tb.Font.Height);
int newCharIndex = tb.GetCharIndexFromPosition(newPos);
if (tb.GetPositionFromCharIndex(newCharIndex).Y == newPos.Y)
{
tb.SelectionStart = newCharIndex;
}
else
{
tb.SelectionStart = tb.GetFirstCharIndexFromLine(oldLineNo - 2);
System.Windows.Forms.SendKeys.Send("{END}");
}
}
}
}
}
public static void LineDown(TextBox tb)
{
int oldCharIndex = tb.SelectionStart;
int oldLineNo = tb.GetLineFromCharIndex(oldCharIndex);
System.Drawing.Point oldCharPos = tb.GetPositionFromCharIndex(oldCharIndex);
System.Drawing.Point oldCaretPos;
if (GetCaretPos(out oldCaretPos))
{
if (oldCharPos == oldCaretPos)
{
if (oldLineNo < tb.GetLineFromCharIndex(tb.Text.Length - 1))
{
tb.SelectionStart = tb.GetFirstCharIndexFromLine(oldLineNo + 1);
tb.ScrollToCaret();
System.Drawing.Point newPos = new System.Drawing.Point(oldCaretPos.X, oldCaretPos.Y + tb.Font.Height);
int newCharIndex = tb.GetCharIndexFromPosition(newPos);
if (tb.GetPositionFromCharIndex(newCharIndex).Y == newPos.Y)
{
tb.SelectionStart = newCharIndex;
}
else
{
tb.SelectionStart = tb.GetFirstCharIndexFromLine(oldLineNo + 1);
System.Windows.Forms.SendKeys.Send("{END}");
}
}
}
else
{
System.Drawing.Point newPos = new System.Drawing.Point(oldCaretPos.X, oldCaretPos.Y + tb.Font.Height);
int newCharIndex = tb.GetCharIndexFromPosition(newPos);
if (tb.GetPositionFromCharIndex(newCharIndex).Y == newPos.Y)
{
tb.SelectionStart = newCharIndex;
}
else
{
tb.SelectionStart = tb.GetFirstCharIndexFromLine(oldLineNo);
System.Windows.Forms.SendKeys.Send("{END}");
}
}
}
}
}
这个想法归功于this answer，您可能还想看看MSDN reference on GetCaretPos和other Caret functions。
答案 2 :(得分：0)
/// ------------------------------------------------------------------------------------
/// <summary>
/// Processes up key when a grid cell is in the edit mode. This overrides the default
/// behavior in a grid cell when it's being edited so using the up arrow will move the
/// IP up one line rather than moving to the previous row.
/// </summary>
/// ------------------------------------------------------------------------------------
protected virtual bool ProcessUpKey(TextBox txtBox)
{
// Don't override the default behavior if all the text is selected or not multi-line.
if (txtBox.SelectedText == txtBox.Text || !txtBox.Multiline)
return false;
int selectionPosition = txtBox.SelectionStart;
// Getting the position after the very last character doesn't work.
if (selectionPosition == txtBox.Text.Length && selectionPosition > 0)
selectionPosition--;
Point pt = txtBox.GetPositionFromCharIndex(selectionPosition);
if (pt.Y == 0)
return false;
pt.Y -= TextRenderer.MeasureText("x", txtBox.Font).Height;
txtBox.SelectionStart = txtBox.GetCharIndexFromPosition(pt);
return true;
}
/// ------------------------------------------------------------------------------------
/// <summary>
/// Processes down key when a grid cell is in the edit mode. This overrides the default
/// behavior in a grid cell when it's being edited so using the down arrow will move the
/// IP down one line rather than moving to the next row.
/// </summary>
/// ------------------------------------------------------------------------------------
protected virtual bool ProcessDownKey(TextBox txtBox)
{
// Don't override the default behavior if all the text is selected or not multi-line.
if (txtBox.SelectedText == txtBox.Text || !txtBox.Multiline)
return false;
int chrIndex = txtBox.SelectionStart;
Point pt = txtBox.GetPositionFromCharIndex(chrIndex);
pt.Y += TextRenderer.MeasureText("x", txtBox.Font).Height;
var proposedNewSelection = txtBox.GetCharIndexFromPosition(pt);
if (proposedNewSelection <= chrIndex)
return false; // Don't let "down" take you *up*.
txtBox.SelectionStart = proposedNewSelection;
return true;
}