括号出现变形，中间有中断
string temp2 = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "test.pdf");
using var pdf = new Spire.Pdf.PdfDocument();
pdf.LoadFromFile(temp2);
for (int i = 0; i < pdf.Pages.Count; i++)
{
var image = pdf.SaveAsImage(i, Spire.Pdf.Graphics.PdfImageType.Bitmap, 150, 150);
string imageFile = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, i + ".png");
image.Save(imageFile, ImageFormat.Png);
}
