64 lines
1.8 KiB
JavaScript
64 lines
1.8 KiB
JavaScript
"use strict";
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define(function (require, exports, module) {
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class A4Utils {
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constructor() {
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let dpi = this.GetDPI();
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console.log("dpi: ", dpi)
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//A0纸尺寸841mm×1189mm
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//
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// A1纸尺寸594mm×841mm
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//
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// A2纸尺寸420mm×594mm
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//
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// A3纸尺寸297mm×420mm
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//
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// A4纸尺寸210mm×297mm
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//
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// A5纸尺寸148mm×210mm
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//
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// A6纸尺寸105mm×148mm
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//
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// A7纸尺寸74mm×105mm
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//
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// A8纸尺寸52mm×74mm
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//
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// A9纸尺寸37mm×52mm
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let width_mm = 210; // A4纸宽度，单位：毫米
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let height_mm = 297; // A4纸高度，单位：毫米
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let width_px = this.MmToPixel(width_mm, dpi);
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let height_px = this.MmToPixel(height_mm, dpi);
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this.width = width_px;
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this.height = height_px;
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}
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/**
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* A4纸
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* 计算 dpi
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*/
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GetDPI() {
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let tempDiv = document.createElement("div");
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tempDiv.style.width = "1in";
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tempDiv.style.height = "1in";
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tempDiv.style.visibility = "hidden";
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//
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// tempDiv.style.position = "fixed"
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// tempDiv.style.top = "0px"
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// tempDiv.style.left = "0px"
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document.body.appendChild(tempDiv);
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let dpi = tempDiv.offsetWidth;
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// alert(123)
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document.body.removeChild(tempDiv);
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return dpi;
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}
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MmToPixel(mm, dpi) {
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// 1 inch = 25.4 mm
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let inches = mm / 25.4;
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let pixels = inches * dpi;
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return Math.round(pixels);
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}
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}
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module.exports = new A4Utils();
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}) |