c#(mobile) 绘制文字自动换行的实现

问题描述：写一个自定义的控件，在使用Graphics.DrawString()方法时发现.NET Compact Framework不支持自动换行。

问题解决：自己写了一个方法实现自动换行，主要实现了以下情况的换行：1.文本长度超过指定宽度2.文本中包含回车换行 符 。相关代码如下：

///

/// 绘制文本自动换行（超出截断）

///

/// 绘图图面

/// 字体

/// 文本

/// 绘制范围

private void DrawStringWrap(Graphics graphic, Font font, string text, Rectangle recangle)

{

List textRows = GetStringRows(graphic, font, text, recangle.Width);

int rowHeight = (int)(Math.Ceiling(graphic.MeasureString(\”测试\”, font).Height));

int maxRowCount = recangle.Height / rowHeight;
int drawRowCount = (maxRowCount < textRows.Count) ? maxRowCount : textRows.Count;

int top = (recangle.Height - rowHeight * drawRowCount) / 2;

StringFormat sf = new StringFormat();
sf.Alignment = StringAlignment.Near;
sf.LineAlignment = StringAlignment.Center;

for (int i = 0; i < drawRowCount; i++)
{
Rectangle fontRectanle = new Rectangle(recangle.Left, top + rowHeight * i, recangle.Width, rowHeight);
graphic.DrawString(textRows, font, new SolidBrush(Color.Black), fontRectanle, sf);
}

}

/// <summary>
/// 将文本分行
/// </summary>
/// <param name=\"graphic\">绘图图面</param>
/// <param name=\"font\">字体</param>
/// <param name=\"text\">文本</param>
/// <param name=\"width\">行宽</param>
/// <returns></returns>
private List<string> GetStringRows(Graphics graphic, Font font, string text, int width)
{
int RowBeginIndex = 0;
int rowEndIndex = 0;
int textLength = text.Length;
List<string> textRows = new List<string>();

for (int index = 0; index < textLength; index++)
{
rowEndIndex = index;

if (index == textLength - 1)
{
textRows.Add(text.Substring(RowBeginIndex));
}
else if (rowEndIndex + 1 < text.Length && text.Substring(rowEndIndex, 2) == \"\\r\\n\")
{
textRows.Add(text.Substring(RowBeginIndex, rowEndIndex - RowBeginIndex));
rowEndIndex=index += 2;
RowBeginIndex = rowEndIndex;
}
else if (graphic.MeasureString(text.Substring(RowBeginIndex, rowEndIndex - RowBeginIndex + 1), font).Width > width)
{
textRows.Add(text.Substring(RowBeginIndex, rowEndIndex - RowBeginIndex));
RowBeginIndex = rowEndIndex;
}
}

return textRows;
}