C#一些常用的图片操作方法：生成文字图片 合并图片等

/// <summary>
/// 生成文字图片
/// </summary>
/// <param name="text"></param>
/// <param name="isBold"></param>
/// <param name="fontSize"></param>
public Image CreateImage(string text, bool isBold, int fontSize)
{
int wid = 400;
int high = 200;
Font font;
if (isBold)
{
font = new Font("Arial", fontSize, FontStyle.Bold);

}
else
{
font = new Font("Arial", fontSize, FontStyle.Regular);

}
//绘笔颜色
SolidBrush brush = new SolidBrush(Color.Black);
StringFormat format = new StringFormat(StringFormatFlags.NoClip);
Bitmap image = new Bitmap(wid, high);
Graphics g = Graphics.FromImage(image);
SizeF sizef = g.MeasureString(text, font, PointF.Empty, format);//得到文本的宽高
int width = (int)(sizef.Width + 1);
int height = (int)(sizef.Height + 1);
image.Dispose();
image = new Bitmap(width, height);
g = Graphics.FromImage(image);
g.Clear(Color.White);//透明

RectangleF rect = new RectangleF(0, 0, width, height);
//绘制图片
g.DrawString(text, font, brush, rect);
//释放对象
g.Dispose();
return image;
}

/// <summary>
/// 合并图片
/// </summary>
/// <param name="imgBack"></param>
/// <param name="img"></param>
/// <returns></returns>
public static Bitmap CombinImage(Image imgBack, Image img, int xDeviation = 0, int yDeviation = 0)
{

Bitmap bmp = new Bitmap(imgBack.Width, imgBack.Height + img.Height);

Graphics g = Graphics.FromImage(bmp);
g.Clear(Color.White);
g.DrawImage(imgBack, 0, 0, imgBack.Width, imgBack.Height); //g.DrawImage(imgBack, 0, 0, 相框宽, 相框高);

//g.FillRectangle(System.Drawing.Brushes.White, imgBack.Width / 2 - img.Width / 2 - 1, imgBack.Width / 2 - img.Width / 2 - 1,1,1);//相片四周刷一层黑色边框

//g.DrawImage(img, 照片与相框的左边距, 照片与相框的上边距, 照片宽, 照片高);

g.DrawImage(img, imgBack.Width / 2 - img.Width / 2 + xDeviation, imgBack.Height + yDeviation, img.Width, img.Height);
GC.Collect();
return bmp;
}

/// <summary>
/// Resize图片
/// </summary>
/// <param name="bmp">原始Bitmap</param>
/// <param name="newW">新的宽度</param>
/// <param name="newH">新的高度</param>
/// <param name="mode">保留着，暂时未用</param>
/// <returns>处理以后的图片</returns>
public static Image ResizeImage(Image bmp, int newW, int newH, int mode)
{
try
{
Image b = new Bitmap(newW, newH);
Graphics g = Graphics.FromImage(b);

// 插值算法的质量
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
g.DrawImage(bmp, new Rectangle(0, 0, newW, newH), new Rectangle(0, 0, bmp.Width, bmp.Height),
GraphicsUnit.Pixel);
g.Dispose();
return b;
}
catch
{
return null;
}
}

Bitmap bmp = CombinImage(ms, img1);
MemoryStream ms = new MemoryStream();
bmp.Save(ms, ImageFormat.Png);