Question

我有以下问题。我想在位图图像中制作一些图形，如债券形式

我可以在图像中写一个文字
但我会在不同的位置写更多的文字

Bitmap a = new Bitmap(@"path\picture.bmp");

using(Graphics g = Graphics.FromImage(a))
{
 g.DrawString(....); // requires font, brush etc
}

如何编写文本并保存并在保存的图像中写入另一个文本

Answer 1

要绘制多个字符串，请多次调用graphics.DrawString。您可以指定绘制字符串的位置。这个例子我们将绘制两个字符串“Hello”，“Word”（蓝色前面的“Hello”，红色的“Word”）：

string firstText = "Hello";
string secondText = "World";

PointF firstLocation = new PointF(10f, 10f);
PointF secondLocation = new PointF(10f, 50f);

string imageFilePath = @"path\picture.bmp"
Bitmap bitmap = (Bitmap)Image.FromFile(imageFilePath);//load the image file

using(Graphics graphics = Graphics.FromImage(bitmap))
{
    using (Font arialFont =  new Font("Arial", 10))
    {
        graphics.DrawString(firstText, arialFont, Brushes.Blue, firstLocation);
        graphics.DrawString(secondText, arialFont, Brushes.Red, secondLocation);
    }
}

bitmap.Save(imageFilePath);//save the image file

编辑“我添加了一个加载并保存代码”。

您可以随时Image.FromFile打开位图文件，并使用上面的代码在其上绘制新文本。然后保存图像文件bitmap.Save

Answer 2

以下是Graphics.DrawString来自here的调用示例：

g.DrawString("My\nText", new Font("Tahoma", 40), Brushes.White, new PointF(0, 0));

它显然依赖于安装了一个名为Tahoma的字体。

Brushes类有许多内置画笔。

另请参阅Graphics.DrawString的MSDN页面。

Answer 3

要保存对同一文件的更改，我必须在Jalal Said问题上合并NSGaga的答案和this的答案。您需要基于旧的 Bitmap 对象创建一个新的 Bitmap 对象，配置旧的 Bitmap 对象，然后使用新对象进行保存：

string firstText = "Hello";
string secondText = "World";

PointF firstLocation = new PointF(10f, 10f);
PointF secondLocation = new PointF(10f, 50f);

string imageFilePath = @"path\picture.bmp";

Bitmap newBitmap;
using (var bitmap = (Bitmap)Image.FromFile(imageFilePath))//load the image file
{
    using(Graphics graphics = Graphics.FromImage(bitmap))
    {
        using (Font arialFont =  new Font("Arial", 10))
        {
            graphics.DrawString(firstText, arialFont, Brushes.Blue, firstLocation);
            graphics.DrawString(secondText, arialFont, Brushes.Red, secondLocation);
        }
    }
    newBitmap = new Bitmap(bitmap);
}

newBitmap.Save(imageFilePath);//save the image file
newBitmap.Dispose();

Answer 4

    public string imageFilePath = null;
    public string textOnImage = null;

    public Image baseImage;
    public Image modifiedImage;

    public int xcoOrdinate = 0;
    public int ycoOrdinate = 0;

    public Form1()
    {
        InitializeComponent();
    }

    private void buttonLoadImage_Click(object sender, EventArgs e)
    {
        try
        {
            OpenFileDialog uploadfileDialog = new OpenFileDialog();
            uploadfileDialog.Filter = "All Files (*.*)|*.*";
            uploadfileDialog.Multiselect = false;

            if (uploadfileDialog.ShowDialog() == DialogResult.OK)
            {
                imageFilePath = uploadfileDialog.FileName;
            }

            baseImage = Image.FromFile(imageFilePath);
            modifiedImage = (Image)baseImage.Clone();
            pictureBoxToShowPic.Image = baseImage;
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Source + " : " + ex.Message);
        }            
    }

    public void paint()
    {
        try
        {
            Graphics g = Graphics.FromImage(modifiedImage);
            using (Font myfont = new Font("Arial", 14))
            {
                var format = new StringFormat
                {
                    Alignment = StringAlignment.Center,
                    LineAlignment = StringAlignment.Center
                };

                g.DrawString(textOnImage, myfont, Brushes.Black, new Point(xcoOrdinate, ycoOrdinate), format);
            }
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Source + " : " + ex.Message);
        }
    }

    private void buttonAddText_Click(object sender, EventArgs e)
    {
        try
        {
            textOnImage = textBoxWriteText.Text;
            paint();
            pictureBoxToShowPic.Image = modifiedImage;
            pictureBoxToShowPic.Refresh();
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Source + " : " + ex.Message);
        }
    }

    private void pictureBoxToShowPic_MouseDoubleClick(object sender, MouseEventArgs e)
    {
        try
        {
            xcoOrdinate = e.X;
            ycoOrdinate = e.Y;
        }            
        catch (Exception ex)
        {
            MessageBox.Show(ex.Source + " : " + ex.Message);
        }
    }

    private void buttonSaveImage_Click(object sender, EventArgs e)
    {
        try
        {
            SaveFileDialog savefileDialog = new SaveFileDialog();

            savefileDialog.Filter = "Images|*.jpg ; *.png ; *.bmp";

            if (savefileDialog.ShowDialog() == DialogResult.OK)
            {
                imageFilePath = savefileDialog.FileName;
            }

            modifiedImage.Save(imageFilePath);
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Source + " : " + ex.Message);
        }
    }

Answer 5

如果有人对此代码行有疑问：

using(Graphics graphics = Graphics.FromImage(bitmap))

解决方案是：

Bitmap bitmap = (Bitmap)**System.Drawing.Image.FromFile**(@"C:\Documents and Settings\", true);

在c＃中的图像上写文本

5 个答案: