如何在运行时动态地从文本生成图像

Question

任何人都可以指导如何从输入文本生成图像。图片可能有任何扩展名都没关系。

Answer 1

好的，假设您想在C＃中的图像上绘制字符串，则需要在此处使用System.Drawing命名空间：

private Image DrawText(String text, Font font, Color textColor, Color backColor)

{

    //first, create a dummy bitmap just to get a graphics object

    Image img = new Bitmap(1, 1);

    Graphics drawing = Graphics.FromImage(img);

    //measure the string to see how big the image needs to be

    SizeF textSize = drawing.MeasureString(text, font);

    //free up the dummy image and old graphics object

    img.Dispose();

    drawing.Dispose();

    //create a new image of the right size

    img = new Bitmap((int) textSize.Width, (int)textSize.Height);

    drawing = Graphics.FromImage(img);

    //paint the background

    drawing.Clear(backColor);

    //create a brush for the text

    Brush textBrush = new SolidBrush(textColor);

    drawing.DrawString(text, font, textBrush, 0, 0);

    drawing.Save();

    textBrush.Dispose();

    drawing.Dispose();

    return img;

}

此代码将首先测量字符串，然后创建正确大小的图像。

如果要保存此函数的返回，只需调用返回图像的Save方法。

Answer 2

谢谢卡扎尔。对以前使用USING处置图像/图形对象以及引入最小尺寸参数后的使用方法的回答略有改进

    private Image DrawTextImage(String currencyCode, Font font, Color textColor, Color backColor) {

        return DrawTextImage(currencyCode, font, textColor, backColor, Size.Empty);

    }

    private Image DrawTextImage(String currencyCode, Font font, Color textColor, Color backColor, Size minSize) {

        //first, create a dummy bitmap just to get a graphics object

        SizeF textSize;

        using (Image img = new Bitmap(1, 1)) {

            using (Graphics drawing = Graphics.FromImage(img)) {

                //measure the string to see how big the image needs to be

                textSize = drawing.MeasureString(currencyCode, font);

                if (!minSize.IsEmpty) {

                    textSize.Width = textSize.Width > minSize.Width ? textSize.Width : minSize.Width;

                    textSize.Height = textSize.Height > minSize.Height ? textSize.Height : minSize.Height;

                }

            }

        }

        //create a new image of the right size

        Image retImg = new Bitmap((int)textSize.Width, (int)textSize.Height);

        using (var drawing = Graphics.FromImage(retImg)) {

            //paint the background

            drawing.Clear(backColor);

            //create a brush for the text

            using (Brush textBrush = new SolidBrush(textColor)) {

                drawing.DrawString(currencyCode, font, textBrush, 0, 0);

                drawing.Save();

            }

        }

        return retImg;

    }