asp.net将文字绘制成图片

可以将字符串输出为位图，并在前台页面显示。同时支持自动换行。

调用代码：其中，str为要输出的文本。

                Bitmap newBitmap = null;
                Graphics g = null;
                string str = allTextTrans;
                try
                {
                    Font strFont = new Font("宋体", 12);
                    newBitmap = new Bitmap(800, 1000, PixelFormat.Format32bppArgb);
                    g = Graphics.FromImage(newBitmap);
                    Rectangle recangle = new Rectangle(0, 0, 800, 1000);
                    DrawStringWrap(g, strFont, allTextTrans, recangle);
                    MemoryStream tempStream = new MemoryStream();
                    newBitmap.Save(tempStream, ImageFormat.Png);
                    Response.ClearContent();
                    Response.ContentType = "image/png";
                    Response.BinaryWrite(tempStream.ToArray());
                    Response.End();
                }
                finally
                {
                    if (g != null) g.Dispose();
                    if (newBitmap != null) newBitmap.Dispose();
                }

绘制和分行函数：

/// <summary>
        /// 绘制文本自动换行（超出截断）
        /// </summary>
        /// <param name=\"graphic\">绘图图面</param>
        /// <param name=\"font\">字体</param>
        /// <param name=\"text\">文本</param>
        /// <param name=\"recangle\">绘制范围</param>
        private void DrawStringWrap(Graphics graphic, Font font, string text, Rectangle recangle)
        {
            List<string> 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;
            int top = 0;
            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[i], 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,1) == "\n")
                {
                    textRows.Add(text.Substring(RowBeginIndex, rowEndIndex - RowBeginIndex));
                    rowEndIndex = index += 1;
                    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;
        }
    }

展示效果：

参考资料：http://blog.163.com/gsrwsh@126/blog/static/75794506201061492755492/