Asp.Net Core 使用 SixLabors 生成分享图/使用自定义字体(2.xx)版本

注意：这里的文档为最新版的 SixLabors.ImageSharp 2.xx 和 SixLabors.ImageSharp.Drawin 1.0.0-beta15

Asp.Net Core 跨平台使用图像库，推荐使用 SixLabors.ImageSharp。原因呢，简单、快平台 (相对于 System.Draw.Common

安装

对了，在安装时一定要打开 include prereleases，不然你看不到 SixLabors.ImageSharp.Drawing

首先下载自定义字体

自定义字体方面，我推荐使用小米最近刚出的可商用的字体 MiSans。

下载地址

https://kpan.mioffice.cn/webfolder/ext/IUrT%23akFnZ0%40?n=0.3820181893993342

密码：8D40

我尝试过阿里的那个啥字体，但是感觉少了什么东西，字都粘到一块了。还是用小米的吧

下载完后放在当前目录下的 fonts 目录

加载字体

我们要做的事，就是如果存在自定义字体则使用自定义字体，如果没有则使用系统默认的 Arial

FontFamily normalFontFamily = SystemFonts.Families.FirstOrDefault();
FontFamily boldFontFamily = SystemFonts.Families.FirstOrDefault() ;
var fonts = new FontCollection();
var fonts2 = new FontCollection();

if(File.Exists("./fonts/MiSans-Normal.ttf"))
{
    normalFontFamily = fonts.Add("./fonts/MiSans-Normal.ttf");
}

if(File.Exists("./fonts/MiSans-Medium.ttf"))
{
    boldFontFamily = fonts2.Add("./fonts/MiSans-Medium.ttf");
}

使用

var templatePath = "./images/bg.png";
var outputImage = Image.Load(templatePath);
var ms = new MemoryStream();

// 先画标题

var title = task.Title;
var color = new Color(new Bgr24(195, 99, 21));
var top = 300;
var fontSize = 64;
var font = new Font(boldFontFamily, fontSize, FontStyle.Bold);


var textOptions = new TextOptions(font)
{
    TabWidth = 16,
    VerticalAlignment = VerticalAlignment.Top,
    HorizontalAlignment = HorizontalAlignment.Left,
    WrappingLength = 650
};

var size = TextMeasurer.Measure(title, textOptions);


if (size.Width > 650)
{
    if (size.Width > 850)
    {
        top = 270;
    }

    fontSize = 48;
    font = new Font(boldFontFamily, fontSize, FontStyle.Bold);
}


textOptions.Origin = new PointF(70, top);
textOptions.Font = font;

outputImage.Mutate(o =>
{
    o.DrawText(textOptions, title, font, color);
});


// 再画要求
decimal minAward = decimal.Zero;
if (task.Award != null)
{
    if (task.Award.RewardConfigs != null && task.Award.RewardConfigs.Count > 0)
    {
        var awards = task.Award.RewardConfigs.OrderBy(x => x.Money).ToList();
        if (awards[0].Money > 0)
            minAward = awards[0].Money;
    }
}

font = new Font(normalFontFamily, 36, FontStyle.Bold);
color = new Color(new Rgb24(189, 117, 46));

textOptions.Font = font;

outputImage.Mutate(o =>
{

    textOptions.Origin = new PointF(70, 420);
    o.DrawText(textOptions, "奖励金额：最低奖励" + (minAward > decimal.Zero ? minAward : '-') + "元", font, color);

    textOptions.Origin = new PointF(70, 470);
    o.DrawText(textOptions, "粉丝要求：" + (task.FanCount == 0 ? "不限" : task.FanCount), font, color, );

    textOptions.Origin = new PointF(70, 520);
    o.DrawText(textOptions, "报名名额：" + (task.Qquota == 0 ? "不限" : task.Qquota + " 人"), font, color, );
});

outputImage.SaveAsJpeg(ms);
return new FileContentResult(ms.ToArray(), @"image/jpeg");