在jsPDF中创建虚线或虚线

时间:2015-01-03 23:42:25

标签: javascript pdf line jspdf

我需要在使用jsPDF创建的PDF中绘制一条虚线(https://mrrio.github.io/jsPDF/doc/symbols/jsPDF.html

创建一个简单的行:

doc.line(20, 25, 60, 25);

http://jsfiddle.net/S3XRp/78/

如何创建虚线或虚线?

2 个答案:

答案 0 :(得分:8)

我遇到了同样的问题,并且这样做了:

/**
 * Draws a dotted line on a jsPDF doc between two points.
 * Note that the segment length is adjusted a little so
 * that we end the line with a drawn segment and don't
 * overflow.
 */
function dottedLine(doc, xFrom, yFrom, xTo, yTo, segmentLength)
{
    // Calculate line length (c)
    var a = Math.abs(xTo - xFrom);
    var b = Math.abs(yTo - yFrom);
    var c = Math.sqrt(Math.pow(a,2) + Math.pow(b,2));

    // Make sure we have an odd number of line segments (drawn or blank)
    // to fit it nicely
    var fractions = c / segmentLength;
    var adjustedSegmentLength = (Math.floor(fractions) % 2 === 0) ? (c / Math.ceil(fractions)) : (c / Math.floor(fractions));

    // Calculate x, y deltas per segment
    var deltaX = adjustedSegmentLength * (a / c);
    var deltaY = adjustedSegmentLength * (b / c);

    var curX = xFrom, curY = yFrom;
    while (curX <= xTo && curY <= yTo)
    {
        doc.line(curX, curY, curX + deltaX, curY + deltaY);
        curX += 2*deltaX;
        curY += 2*deltaY;
    }
}

答案 1 :(得分:1)

jsPDF的更高版本具有内置功能:

setLineDash [Docs]

例如,以下示例绘制一条虚线,该虚线表示绘制的10mm的线,然后沿着从左到右的方向重复10mm的空间。我假设您正在绘制具有所有默认设置(即A4,毫米单位等)的页面:

doc.setLineDash([10, 10], 0);
doc.line(20, 25, 60, 25);

enter image description here

下面将绘制7mm的线,3mm的空间,1mm的线,3mm的空间,然后重复,但是,它将在10mm处开始图案,因此要绘制的虚线的第一部分是1mm的部分:

doc.setLineDash([7, 3, 1, 3], 10);
doc.line(20, 25, 60, 25);

enter image description here