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Asp.net網頁設計簽名位置?

請問如果要使用Asp.net網頁(搭配VB語法)去設計一個讓使用者用平板或手機簽名的位置,有參考的資料嗎?
PS:有查到可以在ASP.NET Web Forms使用jSignature,不知道怎麼整合進去?我是使用visual studio 2013設計。

謝謝!

新開一個webform網頁
https://ithelp.ithome.com.tw/upload/images/20190110/20068241lcwuHNOV36.jpg

1 個回答

6
純真的人
iT邦高手 1 級 ‧ 2019-01-10 09:18:43
最佳解答

我目前都用這套網頁簽名
你試試
https://github.com/szimek/signature_pad

我的用法:(我刪除我部份的程式碼)

<script type="text/javascript" src="js/signature_pad.js"></script>
<style type="text/css">
.Canvas_Dp{width:550px;height:150px;}
@media screen and (max-width: 560px)
{
    .Canvas_Dp{width:300px;height:120px;}
    }
</style>

<form method="post" action="" id="form1" onsubmit="return go();">
<input type="button" value=" 清 除 " name="B3" onclick="clearButton('Signature')" />
<hr />
<canvas class="Canvas_Dp" id="Signature" style="border:1px #000000 solid;"></canvas>
<input type="hidden" id="Signature_Over" name="Signature" value="" />
<input type="hidden" id="Signature_Check" name="Signature_Check" value="" />
<input type="submit" value=" 送出 Send " />
</form>
<script type="text/javascript">
    function go() {
        var form1 = document.getElementById("form1");

        var canvas = document.getElementsByTagName("canvas");
        for (var i = 0; i < canvas.length; i++) {
            var Obj = document.getElementById(canvas[i].id + "_Over");
            if (Obj != null) {
                Obj.value = signaturePad[i].toDataURL();
            }
        }

        if (form1.Signature.value == form1.Signature_Check.value) {
            alert("請完成簽名!");
        } else {
            if (window.confirm("確定送出簽名資料?!")) {
                return true;
            } else {
                return false;
            }
        }
        return false;
    }

    if (document.createElement('canvas').getContext) {

        var canvas = document.getElementsByTagName("canvas");
        var signaturePad = new Array();

        /*依位置校正,修正畫板焦點*/
        function resizeCanvas() {
            var ratio = Math.max(window.devicePixelRatio || 1, 1);
            for (var i = 0; i < canvas.length; i++) {
                canvas[i].width = canvas[i].offsetWidth * ratio;
                canvas[i].height = canvas[i].offsetHeight * ratio;
                canvas[i].getContext("2d").scale(ratio, ratio);
            }
        }

        window.onresize = resizeCanvas;
        resizeCanvas();

        for (var i = 0; i < canvas.length; i++) {
            signaturePad[i] = new SignaturePad(canvas[i]);
        }

        $(function () {
            for (var i = 0; i < canvas.length; i++) {
                var Obj = document.getElementById(canvas[i].id + "_Over");
                var Check = document.getElementById(canvas[i].id + "_Check");
                if (Obj != null) {
                    if (Obj.value != "") {
                        signaturePad[i].fromDataURL(Obj.value);
                    } else {
                        Check.value = signaturePad[i].toDataURL();
                    }
                }
            }

        })
    } else {
        alert("提醒您,您的瀏覽器不支援簽名功能,建議更換Google Chrome瀏覽器。")
    }
    function clearButton(Obj_Name) {
        for (var i = 0; i < canvas.length; i++) {
            if (canvas[i].id == Obj_Name) {
                signaturePad[i].clear();
                break;
            }
        }
    }
</script>

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badboy01 iT邦新手 5 級 ‧ 2019-01-10 09:56:30 檢舉

感謝大大提供參考資料!來研究看看。

badboy01 iT邦新手 5 級 ‧ 2019-01-10 16:45:20 檢舉

請教大大,我新開一個webform空白網頁,要怎麼放進您貼的程式碼才不會有錯誤訊息?另原始碼上的signature_pad.js檔案在網頁上提供下載只有找到這個signature_pad.umd.js @@?

我的是 Signature Pad v1.5.2
剛看過~你的比較新~你把名稱改一致就好了~

然後script要放在坐後面~
或者你要照他的範例改才對~

這是我那個的JS原始碼

(function (root, factory) {
  if (typeof define === 'function' && define.amd) {
    // AMD. Register as an anonymous module unless amdModuleId is set
    define([], function () {
      return (root['SignaturePad'] = factory());
    });
  } else if (typeof exports === 'object') {
    // Node. Does not work with strict CommonJS, but
    // only CommonJS-like environments that support module.exports,
    // like Node.
    module.exports = factory();
  } else {
    root['SignaturePad'] = factory();
  }
}(this, function () {

/*!
 * Signature Pad v1.5.2
 * https://github.com/szimek/signature_pad
 *
 * Copyright 2015 Szymon Nowak
 * Released under the MIT license
 *
 * The main idea and some parts of the code (e.g. drawing variable width Bézier curve) are taken from:
 * http://corner.squareup.com/2012/07/smoother-signatures.html
 *
 * Implementation of interpolation using cubic Bézier curves is taken from:
 * http://benknowscode.wordpress.com/2012/09/14/path-interpolation-using-cubic-bezier-and-control-point-estimation-in-javascript
 *
 * Algorithm for approximated length of a Bézier curve is taken from:
 * http://www.lemoda.net/maths/bezier-length/index.html
 *
 */
var SignaturePad = (function (document) {
    "use strict";

    var SignaturePad = function (canvas, options) {
        var self = this,
            opts = options || {};

        this.velocityFilterWeight = opts.velocityFilterWeight || 0.7;
        this.minWidth = opts.minWidth || 0.5;
        this.maxWidth = opts.maxWidth || 2.5;
        this.dotSize = opts.dotSize || function () {
            return (this.minWidth + this.maxWidth) / 2;
        };
        this.penColor = opts.penColor || "black";
        this.backgroundColor = opts.backgroundColor || "rgba(0,0,0,0)";
        this.onEnd = opts.onEnd;
        this.onBegin = opts.onBegin;

        this._canvas = canvas;
        this._ctx = canvas.getContext("2d");
        this.clear();

        // we need add these inline so they are available to unbind while still having
        //  access to 'self' we could use _.bind but it's not worth adding a dependency
        this._handleMouseDown = function (event) {
            if (event.which === 1) {
                self._mouseButtonDown = true;
                self._strokeBegin(event);
            }
        };

        this._handleMouseMove = function (event) {
            if (self._mouseButtonDown) {
                self._strokeUpdate(event);
            }
        };

        this._handleMouseUp = function (event) {
            if (event.which === 1 && self._mouseButtonDown) {
                self._mouseButtonDown = false;
                self._strokeEnd(event);
            }
        };

        this._handleTouchStart = function (event) {
            if (event.targetTouches.length == 1) {
                var touch = event.changedTouches[0];
                self._strokeBegin(touch);
             }
        };

        this._handleTouchMove = function (event) {
            // Prevent scrolling.
            event.preventDefault();

            var touch = event.targetTouches[0];
            self._strokeUpdate(touch);
        };

        this._handleTouchEnd = function (event) {
            var wasCanvasTouched = event.target === self._canvas;
            if (wasCanvasTouched) {
                event.preventDefault();
                self._strokeEnd(event);
            }
        };

        this._handleMouseEvents();
        this._handleTouchEvents();
    };

    SignaturePad.prototype.clear = function () {
        var ctx = this._ctx,
            canvas = this._canvas;

        ctx.fillStyle = this.backgroundColor;
        ctx.clearRect(0, 0, canvas.width, canvas.height);
        ctx.fillRect(0, 0, canvas.width, canvas.height);
        this._reset();
    };

    SignaturePad.prototype.toDataURL = function (imageType, quality) {
        var canvas = this._canvas;
        return canvas.toDataURL.apply(canvas, arguments);
    };

    SignaturePad.prototype.fromDataURL = function (dataUrl) {
        var self = this,
            image = new Image(),
            ratio = window.devicePixelRatio || 1,
            width = this._canvas.width / ratio,
            height = this._canvas.height / ratio;

        this._reset();
        image.src = dataUrl;
        image.onload = function () {
            self._ctx.drawImage(image, 0, 0, width, height);
        };
        this._isEmpty = false;
    };

    SignaturePad.prototype._strokeUpdate = function (event) {
        var point = this._createPoint(event);
        this._addPoint(point);
    };

    SignaturePad.prototype._strokeBegin = function (event) {
        this._reset();
        this._strokeUpdate(event);
        if (typeof this.onBegin === 'function') {
            this.onBegin(event);
        }
    };

    SignaturePad.prototype._strokeDraw = function (point) {
        var ctx = this._ctx,
            dotSize = typeof(this.dotSize) === 'function' ? this.dotSize() : this.dotSize;

        ctx.beginPath();
        this._drawPoint(point.x, point.y, dotSize);
        ctx.closePath();
        ctx.fill();
    };

    SignaturePad.prototype._strokeEnd = function (event) {
        var canDrawCurve = this.points.length > 2,
            point = this.points[0];

        if (!canDrawCurve && point) {
            this._strokeDraw(point);
        }
        if (typeof this.onEnd === 'function') {
            this.onEnd(event);
        }
    };

    SignaturePad.prototype._handleMouseEvents = function () {
        this._mouseButtonDown = false;

        this._canvas.addEventListener("mousedown", this._handleMouseDown);
        this._canvas.addEventListener("mousemove", this._handleMouseMove);
        document.addEventListener("mouseup", this._handleMouseUp);
    };

    SignaturePad.prototype._handleTouchEvents = function () {
        // Pass touch events to canvas element on mobile IE.
        this._canvas.style.msTouchAction = 'none';

        this._canvas.addEventListener("touchstart", this._handleTouchStart);
        this._canvas.addEventListener("touchmove", this._handleTouchMove);
        document.addEventListener("touchend", this._handleTouchEnd);
    };

    SignaturePad.prototype.on = function () {
        this._handleMouseEvents();
        this._handleTouchEvents();
    };

    SignaturePad.prototype.off = function () {
        this._canvas.removeEventListener("mousedown", this._handleMouseDown);
        this._canvas.removeEventListener("mousemove", this._handleMouseMove);
        document.removeEventListener("mouseup", this._handleMouseUp);

        this._canvas.removeEventListener("touchstart", this._handleTouchStart);
        this._canvas.removeEventListener("touchmove", this._handleTouchMove);
        document.removeEventListener("touchend", this._handleTouchEnd);
    };

    SignaturePad.prototype.isEmpty = function () {
        return this._isEmpty;
    };

    SignaturePad.prototype._reset = function () {
        this.points = [];
        this._lastVelocity = 0;
        this._lastWidth = (this.minWidth + this.maxWidth) / 2;
        this._isEmpty = true;
        this._ctx.fillStyle = this.penColor;
    };

    SignaturePad.prototype._createPoint = function (event) {
        var rect = this._canvas.getBoundingClientRect();
        return new Point(
            event.clientX - rect.left,
            event.clientY - rect.top
        );
    };

    SignaturePad.prototype._addPoint = function (point) {
        var points = this.points,
            c2, c3,
            curve, tmp;

        points.push(point);

        if (points.length > 2) {
            // To reduce the initial lag make it work with 3 points
            // by copying the first point to the beginning.
            if (points.length === 3) points.unshift(points[0]);

            tmp = this._calculateCurveControlPoints(points[0], points[1], points[2]);
            c2 = tmp.c2;
            tmp = this._calculateCurveControlPoints(points[1], points[2], points[3]);
            c3 = tmp.c1;
            curve = new Bezier(points[1], c2, c3, points[2]);
            this._addCurve(curve);

            // Remove the first element from the list,
            // so that we always have no more than 4 points in points array.
            points.shift();
        }
    };

    SignaturePad.prototype._calculateCurveControlPoints = function (s1, s2, s3) {
        var dx1 = s1.x - s2.x, dy1 = s1.y - s2.y,
            dx2 = s2.x - s3.x, dy2 = s2.y - s3.y,

            m1 = {x: (s1.x + s2.x) / 2.0, y: (s1.y + s2.y) / 2.0},
            m2 = {x: (s2.x + s3.x) / 2.0, y: (s2.y + s3.y) / 2.0},

            l1 = Math.sqrt(dx1*dx1 + dy1*dy1),
            l2 = Math.sqrt(dx2*dx2 + dy2*dy2),

            dxm = (m1.x - m2.x),
            dym = (m1.y - m2.y),

            k = l2 / (l1 + l2),
            cm = {x: m2.x + dxm*k, y: m2.y + dym*k},

            tx = s2.x - cm.x,
            ty = s2.y - cm.y;

        return {
            c1: new Point(m1.x + tx, m1.y + ty),
            c2: new Point(m2.x + tx, m2.y + ty)
        };
    };

    SignaturePad.prototype._addCurve = function (curve) {
        var startPoint = curve.startPoint,
            endPoint = curve.endPoint,
            velocity, newWidth;

        velocity = endPoint.velocityFrom(startPoint);
        velocity = this.velocityFilterWeight * velocity
            + (1 - this.velocityFilterWeight) * this._lastVelocity;

        newWidth = this._strokeWidth(velocity);
        this._drawCurve(curve, this._lastWidth, newWidth);

        this._lastVelocity = velocity;
        this._lastWidth = newWidth;
    };

    SignaturePad.prototype._drawPoint = function (x, y, size) {
        var ctx = this._ctx;

        ctx.moveTo(x, y);
        ctx.arc(x, y, size, 0, 2 * Math.PI, false);
        this._isEmpty = false;
    };

    SignaturePad.prototype._drawCurve = function (curve, startWidth, endWidth) {
        var ctx = this._ctx,
            widthDelta = endWidth - startWidth,
            drawSteps, width, i, t, tt, ttt, u, uu, uuu, x, y;

        drawSteps = Math.floor(curve.length());
        ctx.beginPath();
        for (i = 0; i < drawSteps; i++) {
            // Calculate the Bezier (x, y) coordinate for this step.
            t = i / drawSteps;
            tt = t * t;
            ttt = tt * t;
            u = 1 - t;
            uu = u * u;
            uuu = uu * u;

            x = uuu * curve.startPoint.x;
            x += 3 * uu * t * curve.control1.x;
            x += 3 * u * tt * curve.control2.x;
            x += ttt * curve.endPoint.x;

            y = uuu * curve.startPoint.y;
            y += 3 * uu * t * curve.control1.y;
            y += 3 * u * tt * curve.control2.y;
            y += ttt * curve.endPoint.y;

            width = startWidth + ttt * widthDelta;
            this._drawPoint(x, y, width);
        }
        ctx.closePath();
        ctx.fill();
    };

    SignaturePad.prototype._strokeWidth = function (velocity) {
        return Math.max(this.maxWidth / (velocity + 1), this.minWidth);
    };


    var Point = function (x, y, time) {
        this.x = x;
        this.y = y;
        this.time = time || new Date().getTime();
    };

    Point.prototype.velocityFrom = function (start) {
        return (this.time !== start.time) ? this.distanceTo(start) / (this.time - start.time) : 1;
    };

    Point.prototype.distanceTo = function (start) {
        return Math.sqrt(Math.pow(this.x - start.x, 2) + Math.pow(this.y - start.y, 2));
    };

    var Bezier = function (startPoint, control1, control2, endPoint) {
        this.startPoint = startPoint;
        this.control1 = control1;
        this.control2 = control2;
        this.endPoint = endPoint;
    };

    // Returns approximated length.
    Bezier.prototype.length = function () {
        var steps = 10,
            length = 0,
            i, t, cx, cy, px, py, xdiff, ydiff;

        for (i = 0; i <= steps; i++) {
            t = i / steps;
            cx = this._point(t, this.startPoint.x, this.control1.x, this.control2.x, this.endPoint.x);
            cy = this._point(t, this.startPoint.y, this.control1.y, this.control2.y, this.endPoint.y);
            if (i > 0) {
                xdiff = cx - px;
                ydiff = cy - py;
                length += Math.sqrt(xdiff * xdiff + ydiff * ydiff);
            }
            px = cx;
            py = cy;
        }
        return length;
    };

    Bezier.prototype._point = function (t, start, c1, c2, end) {
        return          start * (1.0 - t) * (1.0 - t)  * (1.0 - t)
               + 3.0 *  c1    * (1.0 - t) * (1.0 - t)  * t
               + 3.0 *  c2    * (1.0 - t) * t          * t
               +        end   * t         * t          * t;
    };

    return SignaturePad;
})(document);

return SignaturePad;

}));

fysh711426 iT邦研究生 4 級 ‧ 2019-01-10 17:34:36 檢舉

筆觸蠻不錯的,不知道繪圖板可不可以用~

fysh711426
那個就跟滑鼠一樣@@..(滑鼠右鍵按下~開始簽名)

badboy01 iT邦新手 5 級 ‧ 2019-01-10 18:15:38 檢舉

我將網頁原始碼複製上去,可是會出現這個訊息物件或屬性不正確querySelector@@"
https://ithelp.ithome.com.tw/upload/images/20190110/20068241gGfZUNEk58.jpg

新的呀..我找時間試試

fysh711426 iT邦研究生 4 級 ‧ 2019-01-10 18:33:19 檢舉

了解,前幾天剛好有系統需要線上簽到
如果確定要做就可以玩玩這個
/images/emoticon/emoticon37.gif

你參考我舊的JS簽名板也是可以
http://jerwei.com/PenBook.aspx

badboy01 iT邦新手 5 級 ‧ 2019-01-11 11:53:13 檢舉

這個也不錯喔~~讚!!!

badboy01 iT邦新手 5 級 ‧ 2019-01-22 14:12:00 檢舉

可惜這不能使用在IE上@@"

IE11可以壓@@..
https://ithelp.ithome.com.tw/upload/images/20190212/200613692azSlwukRz.png

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