C#表单将图像打印得尽可能大
C#表单将图像打印得尽可能大
提问于 2018-09-18 00:37:01
我希望在Windows窗体上打印图像，但希望在不破坏图像的纵横比的情况下，在页面上打印尽可能大的图像。例如，当我想要将一个简单的正方形打印到A4纸上时，它会变成矩形，使用下面的脚本：
private void Page(object sender, PrintPageEventArgs e)
{
Bitmap i = image;
if(e.PageBounds.Height > e.PageBounds.Width)
{
if (i.Width > i.Height)
i.RotateFlip(RotateFlipType.Rotate90FlipNone);
}
else if(e.PageBounds.Width > e.PageBounds.Height)
{
if (i.Height > i.Width)
i.RotateFlip(RotateFlipType.Rotate90FlipNone);
}
e.Graphics.DrawImage(i, new Rectangle(0, 0, e.PageBounds.Width, e.PageBounds.Height));
i.Dispose();
}
我得到了什么(pdf格式)：A rectangle on the A4 paper
另一个例子：
打印：Print image
我不想破坏图像的纵横比
回答 1
Stack Overflow用户
发布于 2018-09-18 01:00:01
试试这个：
private void Page(object sender, PrintPageEventArgs e)
{
using (Bitmap i = image) //are you *really sure* you want to dispose this after printing?
{
var pageRatio = e.PageBounds.Width / (double)e.PageBounds.Height;
var imageRatio = i.Width / (double)i.Height;
//do we need to rotate?
if ( (pageRatio < 1 && imageRatio > 1) || (pageRatio < 1 && imageRatio > 1))
{
i.RotateFlip(RotateFlipType.Rotate90FlipNone);
imageRatio = i.Width / (double)i.Height; //ratio will have changed after rotation
}
var scale = 1.0D;
//do we need to scale?
if (pageRatio > imageRatio)
{ //the page is wider than the image, so scale to the height
scale = e.PageBounds.Height / (double)i.Height;
}
else if (pageRatio < imageRatio)
{ //the page is narrower than the image, so scale to width
scale = e.PageBounds.Width / (double)i.Width;
}
var W = (int)(scale * i.Width);
var H = (int)(scale * i.Height);
e.Graphics.DrawImage(i, new Rectangle(0, 0, W, H));
}
}这将始终从左上角绘制。如果您希望它居中，则需要进行额外的调整：
private void Page(object sender, PrintPageEventArgs e)
{
using (Bitmap i = image) //are you *really sure* you want to dispose this after printing?
{
var pageRatio = e.PageBounds.Width / (double)e.PageBounds.Height;
var imageRatio = i.Width / (double)i.Height;
//do we need to rotate?
if ( (pageRatio < 1 && imageRatio > 1) || (pageRatio < 1 && imageRatio > 1))
{
i.RotateFlip(RotateFlipType.Rotate90FlipNone);
imageRatio = i.Width / (double)i.Height; //ratio will have changed after rotation
}
int T = 0, L = 0; //top, left
var scale = 1.0D;
int W = i.Width, H = i.Height;
//do we need to scale?
if (pageRatio > imageRatio)
{ //the page is wider than the image, so scale to the height
scale = e.PageBounds.Height / (double)i.Height;
W = (int)(scale * i.Width);
H = (int)(scale * i.Height);
L = (e.PageBounds.Width - W)/2;
}
else if (pageRatio < imageRatio)
{ //the page is narrower than the image, so scale to width
scale = e.PageBounds.Width / (double)i.Width;
W = (int)(scale * i.Width);
H = (int)(scale * i.Height);
T = (e.PageBounds.Height - H)/2;
}
e.Graphics.DrawImage(i, new Rectangle(L, T, W+L, H+T));
}
}也就是说，乘以相同的数字。
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/52372267
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