语言:kotlin
适用范围: "JPG" "PNG"等系列图片转PDF
/**
* 转换图片为PDF
*/
private fun convertImgToPdf(bytes: ByteArray): ByteArray {
// 默认A4尺寸
var pageSize = PageSize.A4
// 优先处理图片,防止图片路径或者地址错误加载异常
val itextImage: Image = Image.getInstance(bytes)
// 计算缩放比例和旋转图片,以适应指定尺寸显示
if (itextImage.height > itextImage.width) {
pageSize = RectangleReadOnly(pageSize.height, pageSize.width)
}
val percent = getPercent(itextImage.height, itextImage.width, pageSize.height, pageSize.width)
// 图片显示位置,默认居中
itextImage.alignment = Image.MIDDLE
// 表示是原来图像的比例;
itextImage.scalePercent(percent.toFloat())
// 重置边距margin,居中显示
var marginLeft: Float = (pageSize.getWidth() - itextImage.width * percent / 100) / 2
marginLeft = if (marginLeft > 0) marginLeft else 0F
var marginTop: Float = (pageSize.getHeight() - itextImage.height * percent / 100) / 2
marginTop = if (marginTop > 0) marginTop else 0F
// 初始化PDF画板
val document = Document(pageSize, marginLeft, marginLeft, marginTop, marginTop)
val baos = ByteArrayOutputStream()
PdfWriter.getInstance(document, baos)
// 按照: 打开-新增页面-添加元素 流程处理PDF,多页时执行newPage,add 添加页面即可
document.open()
document.newPage()
document.add(itextImage)
// 处理完页面后关闭就可生成pdf
document.close()
return baos.toByteArray()
}
private int getPercent(float h, float w, float eh, float ew) {
float p2 = h > w ? eh / h * 100 : ew / w * 100;
return Math.round(p2);
}
导入包:
import com.itextpdf.text.Document
import com.itextpdf.text.Image
import com.itextpdf.text.PageSize
import com.itextpdf.text.RectangleReadOnly
import com.itextpdf.text.pdf.PdfWriter