private void butImgLoad_Click(object sender, EventArgs e) { if (txtPage.Text.Trim().Length <= 0) { return; } int p; bool bl = int.TryParse(txtPage.Text.Trim(), out p); if (!bl) { MessageBox.Show("页码不正确无法加载!"); txtPage.Focus(); return; } if (p > ImgPage) { MessageBox.Show("页码超出范围无法加载!"); txtPage.Focus(); return; } Bitmap b = Himg.Getbmp(file, p); if (b == null) { MessageBox.Show("加载图像文件失败!"); txtPage.Focus(); return; } bmp.Add(b); lbImgPage.Items.Add(p.ToString()); }