c#中输入文本文字，将输入的文字生成图片

private void button1_Click(object sender, EventArgs e)
{
//获取文本
string text = this.txtName.Text;

//得到Bitmap(传入Rectangle.Empty自动计算宽高)
Bitmap bmp = TextToBitmap(text, this.txtName.Font, Rectangle.Empty, this.txtName.ForeColor, this.txtName.BackColor);

//用PictureBox显示
this.pictureBox1.Image = bmp;

//保存到桌面save.jpg
string directory = System.Environment.GetFolderPath(System.Environment.SpecialFolder.DesktopDirectory);
bmp.Save(directory + "\\save.jpg", ImageFormat.Jpeg);
}
//定义一个方法
/// <summary>
/// 把文字转换才Bitmap
/// </summary>
/// <param name="text"></param>
/// <param name="font"></param>
/// <param name="rect">用于输出的矩形，文字在这个矩形内显示，为空时自动计算</param>
/// <param name="fontcolor">字体颜色</param>
/// <param name="backColor">背景颜色</param>
/// <returns></returns>
private Bitmap TextToBitmap(string text, Font font, Rectangle rect, Color fontcolor, Color backColor)
{
Graphics g;
Bitmap bmp;
StringFormat format = new StringFormat(StringFormatFlags.NoClip);
if (rect == Rectangle.Empty)
{
bmp = new Bitmap(1, 1);
g = Graphics.FromImage(bmp);
//计算绘制文字所需的区域大小（根据宽度计算长度），重新创建矩形区域绘图
SizeF sizef = g.MeasureString(text, font, PointF.Empty, format);

int width = (int)(sizef.Width + 1);
int height = (int)(sizef.Height + 1);
rect = new Rectangle(0, 0, width, height);
bmp.Dispose();

bmp = new Bitmap(width, height);
}
else
{
bmp = new Bitmap(rect.Width, rect.Height);
}

g = Graphics.FromImage(bmp);

//使用ClearType字体功能
g.TextRenderingHint = System.Drawing.Text.TextRenderingHint.ClearTypeGridFit;
g.FillRectangle(new SolidBrush(backColor), rect);
g.DrawString(text, font, Brushes.Black, rect, format);
return bmp;
}