android 电子签名手写签名功能实现

这个手写的效果就是一个重写的的自定义的view 代码如下：

package com.example.hand.views;import java.util.ArrayList;
import java.util.List;import android.content.Context;
import android.content.res.Resources;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.view.MotionEvent;
import android.view.View;import com.example.hand.R;
import com.example.hand.utils.Bezier;
import com.example.hand.utils.ControlTimedPoints;
import com.example.hand.utils.TimedPoint;public class SignatureView extends View {// View stateprivate List<TimedPoint> mPoints;private boolean mIsEmpty;private float mLastTouchX;private float mLastTouchY;private float mLastVelocity;private float mLastWidth;private RectF mDirtyRect;// Configurable parametersprivate int mMinWidth;private int mMaxWidth;private float mVelocityFilterWeight;private OnSignedListener mOnSignedListener;private Paint mPaint = new Paint();private Path mPath = new Path();private Bitmap mSignatureBitmap = null;private Canvas mSignatureBitmapCanvas = null;public SignatureView(Context context, AttributeSet attrs) {super(context, attrs);TypedArray a = context.getTheme().obtainStyledAttributes(attrs, R.styleable.SignatureView, 0, 0);// Configurable parameterstry {mMinWidth = a.getDimensionPixelSize(R.styleable.SignatureView_minWidth, convertDpToPx(3));mMaxWidth = a.getDimensionPixelSize(R.styleable.SignatureView_maxWidth, convertDpToPx(7));mVelocityFilterWeight = a.getFloat(R.styleable.SignatureView_velocityFilterWeight, 0.9f);mPaint.setColor(a.getColor(R.styleable.SignatureView_penColor, Color.BLACK));} finally {a.recycle();}// Fixed parametersmPaint.setAntiAlias(true);mPaint.setStyle(Paint.Style.STROKE);mPaint.setStrokeCap(Paint.Cap.ROUND);mPaint.setStrokeJoin(Paint.Join.ROUND);// Dirty rectangle to update only the changed portion of the viewmDirtyRect = new RectF();clear();}/*** Set the pen color from a given resource. If the resource is not found,* {@link android.graphics.Color#BLACK} is assumed.* * @param colorRes*            the color resource.*/public void setPenColorRes(int colorRes) {try {setPenColor(getResources().getColor(colorRes));} catch (Resources.NotFoundException ex) {setPenColor(getResources().getColor(Color.BLACK));}}/*** Set the pen color from a given color.* * @param color*            the color.*/public void setPenColor(int color) {mPaint.setColor(color);}/*** Set the minimum width of the stroke in pixel.* * @param minWidth*            the width in dp.*/public void setMinWidth(float minWidth) {mMinWidth = convertDpToPx(minWidth);}/*** Set the maximum width of the stroke in pixel.* * @param maxWidth*            the width in dp.*/public void setMaxWidth(float maxWidth) {mMaxWidth = convertDpToPx(maxWidth);}/*** Set the velocity filter weight.* * @param velocityFilterWeight*            the weight.*/public void setVelocityFilterWeight(float velocityFilterWeight) {mVelocityFilterWeight = velocityFilterWeight;}public void clear() {mPoints = new ArrayList<TimedPoint>();mLastVelocity = 0;mLastWidth = (mMinWidth + mMaxWidth) / 2;mPath.reset();if (mSignatureBitmap != null) {mSignatureBitmap = null;ensureSignatureBitmap();}setIsEmpty(true);invalidate();}@Overridepublic boolean onTouchEvent(MotionEvent event) {if (!isEnabled())return false;float eventX = event.getX();float eventY = event.getY();switch (event.getAction()) {case MotionEvent.ACTION_DOWN:getParent().requestDisallowInterceptTouchEvent(true);mPoints.clear();mPath.moveTo(eventX, eventY);mLastTouchX = eventX;mLastTouchY = eventY;addPoint(new TimedPoint(eventX, eventY));case MotionEvent.ACTION_MOVE:resetDirtyRect(eventX, eventY);addPoint(new TimedPoint(eventX, eventY));break;case MotionEvent.ACTION_UP:resetDirtyRect(eventX, eventY);addPoint(new TimedPoint(eventX, eventY));getParent().requestDisallowInterceptTouchEvent(true);setIsEmpty(false);break;default:return false;}// invalidate();invalidate((int) (mDirtyRect.left - mMaxWidth), (int) (mDirtyRect.top - mMaxWidth),(int) (mDirtyRect.right + mMaxWidth), (int) (mDirtyRect.bottom + mMaxWidth));return true;}@Overrideprotected void onDraw(Canvas canvas) {if (mSignatureBitmap != null) {canvas.drawBitmap(mSignatureBitmap, 0, 0, mPaint);}}public void setOnSignedListener(OnSignedListener listener) {mOnSignedListener = listener;}public boolean isEmpty() {return mIsEmpty;}public Bitmap getSignatureBitmap() {Bitmap originalBitmap = getTransparentSignatureBitmap();Bitmap whiteBgBitmap = Bitmap.createBitmap(originalBitmap.getWidth(), originalBitmap.getHeight(),Bitmap.Config.ARGB_8888);Canvas canvas = new Canvas(whiteBgBitmap);canvas.drawColor(Color.WHITE);canvas.drawBitmap(originalBitmap, 0, 0, null);return whiteBgBitmap;}public void setSignatureBitmap(Bitmap signature) {clear();ensureSignatureBitmap();RectF tempSrc = new RectF();RectF tempDst = new RectF();int dWidth = signature.getWidth();int dHeight = signature.getHeight();int vWidth = getWidth();int vHeight = getHeight();// Generate the required transform.tempSrc.set(0, 0, dWidth, dHeight);tempDst.set(0, 0, vWidth, vHeight);Matrix drawMatrix = new Matrix();drawMatrix.setRectToRect(tempSrc, tempDst, Matrix.ScaleToFit.CENTER);Canvas canvas = new Canvas(mSignatureBitmap);canvas.drawBitmap(signature, drawMatrix, null);setIsEmpty(false);invalidate();}public Bitmap getTransparentSignatureBitmap() {ensureSignatureBitmap();return mSignatureBitmap;}public Bitmap getTransparentSignatureBitmap(boolean trimBlankSpace) {if (!trimBlankSpace) {return getTransparentSignatureBitmap();}ensureSignatureBitmap();int imgHeight = mSignatureBitmap.getHeight();int imgWidth = mSignatureBitmap.getWidth();int backgroundColor = Color.TRANSPARENT;int xMin = Integer.MAX_VALUE, xMax = Integer.MIN_VALUE, yMin = Integer.MAX_VALUE, yMax = Integer.MIN_VALUE;boolean foundPixel = false;// Find xMinfor (int x = 0; x < imgWidth; x++) {boolean stop = false;for (int y = 0; y < imgHeight; y++) {if (mSignatureBitmap.getPixel(x, y) != backgroundColor) {xMin = x;stop = true;foundPixel = true;break;}}if (stop)break;}// Image is empty...if (!foundPixel)return null;// Find yMinfor (int y = 0; y < imgHeight; y++) {boolean stop = false;for (int x = xMin; x < imgWidth; x++) {if (mSignatureBitmap.getPixel(x, y) != backgroundColor) {yMin = y;stop = true;break;}}if (stop)break;}// Find xMaxfor (int x = imgWidth - 1; x >= xMin; x--) {boolean stop = false;for (int y = yMin; y < imgHeight; y++) {if (mSignatureBitmap.getPixel(x, y) != backgroundColor) {xMax = x;stop = true;break;}}if (stop)break;}// Find yMaxfor (int y = imgHeight - 1; y >= yMin; y--) {boolean stop = false;for (int x = xMin; x <= xMax; x++) {if (mSignatureBitmap.getPixel(x, y) != backgroundColor) {yMax = y;stop = true;break;}}if (stop)break;}return Bitmap.createBitmap(mSignatureBitmap, xMin, yMin, xMax - xMin, yMax - yMin);}private void addPoint(TimedPoint newPoint) {mPoints.add(newPoint);if (mPoints.size() > 2) {// To reduce the initial lag make it work with 3 mPoints// by copying the first point to the beginning.if (mPoints.size() == 3)mPoints.add(0, mPoints.get(0));ControlTimedPoints tmp = calculateCurveControlPoints(mPoints.get(0), mPoints.get(1), mPoints.get(2));TimedPoint c2 = tmp.c2;tmp = calculateCurveControlPoints(mPoints.get(1), mPoints.get(2), mPoints.get(3));TimedPoint c3 = tmp.c1;Bezier curve = new Bezier(mPoints.get(1), c2, c3, mPoints.get(2));TimedPoint startPoint = curve.startPoint;TimedPoint endPoint = curve.endPoint;float velocity = endPoint.velocityFrom(startPoint);velocity = Float.isNaN(velocity) ? 0.0f : velocity;velocity = mVelocityFilterWeight * velocity + (1 - mVelocityFilterWeight) * mLastVelocity;// The new width is a function of the velocity. Higher velocities// correspond to thinner strokes.float newWidth = strokeWidth(velocity);// The Bezier's width starts out as last curve's final width, and// gradually changes to the stroke width just calculated. The new// width calculation is based on the velocity between the Bezier's// start and end mPoints.addBezier(curve, mLastWidth, newWidth);mLastVelocity = velocity;mLastWidth = newWidth;// Remove the first element from the list,// so that we always have no more than 4 mPoints in mPoints array.mPoints.remove(0);}}private void addBezier(Bezier curve, float startWidth, float endWidth) {ensureSignatureBitmap();float originalWidth = mPaint.getStrokeWidth();float widthDelta = endWidth - startWidth;float drawSteps = (float) Math.floor(curve.length());for (int i = 0; i < drawSteps; i++) {// Calculate the Bezier (x, y) coordinate for this step.float t = ((float) i) / drawSteps;float tt = t * t;float ttt = tt * t;float u = 1 - t;float uu = u * u;float uuu = uu * u;float x = uuu * curve.startPoint.x;x += 3 * uu * t * curve.control1.x;x += 3 * u * tt * curve.control2.x;x += ttt * curve.endPoint.x;float y = uuu * curve.startPoint.y;y += 3 * uu * t * curve.control1.y;y += 3 * u * tt * curve.control2.y;y += ttt * curve.endPoint.y;// Set the incremental stroke width and draw.mPaint.setStrokeWidth(startWidth + ttt * widthDelta);mSignatureBitmapCanvas.drawPoint(x, y, mPaint);expandDirtyRect(x, y);}mPaint.setStrokeWidth(originalWidth);}private ControlTimedPoints calculateCurveControlPoints(TimedPoint s1, TimedPoint s2, TimedPoint s3) {float dx1 = s1.x - s2.x;float dy1 = s1.y - s2.y;float dx2 = s2.x - s3.x;float dy2 = s2.y - s3.y;TimedPoint m1 = new TimedPoint((s1.x + s2.x) / 2.0f, (s1.y + s2.y) / 2.0f);TimedPoint m2 = new TimedPoint((s2.x + s3.x) / 2.0f, (s2.y + s3.y) / 2.0f);float l1 = (float) Math.sqrt(dx1 * dx1 + dy1 * dy1);float l2 = (float) Math.sqrt(dx2 * dx2 + dy2 * dy2);float dxm = (m1.x - m2.x);float dym = (m1.y - m2.y);float k = l2 / (l1 + l2);TimedPoint cm = new TimedPoint(m2.x + dxm * k, m2.y + dym * k);float tx = s2.x - cm.x;float ty = s2.y - cm.y;return new ControlTimedPoints(new TimedPoint(m1.x + tx, m1.y + ty), new TimedPoint(m2.x + tx, m2.y + ty));}private float strokeWidth(float velocity) {return Math.max(mMaxWidth / (velocity + 1), mMinWidth);}/*** Called when replaying history to ensure the dirty region includes all* mPoints.* * @param historicalX*            the previous x coordinate.* @param historicalY*            the previous y coordinate.*/private void expandDirtyRect(float historicalX, float historicalY) {if (historicalX < mDirtyRect.left) {mDirtyRect.left = historicalX;} else if (historicalX > mDirtyRect.right) {mDirtyRect.right = historicalX;}if (historicalY < mDirtyRect.top) {mDirtyRect.top = historicalY;} else if (historicalY > mDirtyRect.bottom) {mDirtyRect.bottom = historicalY;}}/*** Resets the dirty region when the motion event occurs.* * @param eventX*            the event x coordinate.* @param eventY*            the event y coordinate.*/private void resetDirtyRect(float eventX, float eventY) {// The mLastTouchX and mLastTouchY were set when the ACTION_DOWN motion// event occurred.mDirtyRect.left = Math.min(mLastTouchX, eventX);mDirtyRect.right = Math.max(mLastTouchX, eventX);mDirtyRect.top = Math.min(mLastTouchY, eventY);mDirtyRect.bottom = Math.max(mLastTouchY, eventY);}private void setIsEmpty(boolean newValue) {mIsEmpty = newValue;if (mOnSignedListener != null) {if (mIsEmpty) {mOnSignedListener.onClear();} else {mOnSignedListener.onSigned();}}}private void ensureSignatureBitmap() {if (mSignatureBitmap == null) {mSignatureBitmap = Bitmap.createBitmap(getWidth(), getHeight(), Bitmap.Config.ARGB_8888);mSignatureBitmapCanvas = new Canvas(mSignatureBitmap);}}private int convertDpToPx(float dp) {return Math.round(dp * (getResources().getDisplayMetrics().xdpi / DisplayMetrics.DENSITY_DEFAULT));}public interface OnSignedListener {public void onSigned();public void onClear();}
}

Demo源码下载链接

最后我集成到项目里面的效果图如上图

如果大家有其他问题欢迎加入我的qq群讨论开发一群：454430053开发二群：537532956

android 电子签名手写签名功能实现相关推荐

Android 电子签名/手写签名保存到相册详解
ps:因公司推崇线上信息办公化设计到客户签名将客户签好的名字上传到服务器因此写了一个demo 废话不多哔哔上效果图: 这里我运用的是自定义view //权限<uses-permissi ...
android 手写签批_Android自定义实现手写签名功能
一.Android自定义View步骤 : 自定义属性: 选择和设置构造方法: 重写onMeasure()方法: 重写onDraw()方法: 重写onLayout()方法: 重写其他事件的方法(滑动监听 ...
Android手写签名功能（包含画米字格，人名和书写轨迹）
本文主要介绍Android手写签名的功能实现,效果如下图 1.根据人名的个数绘制人的名称这个逻辑分几个步骤:首先创建画笔,然后根据一个字,创建一个字的矩形框,然后根据矩形框获取到画这个字的宽高. / ...
java实现手写签名,Android实现手写签名
本文实例为大家分享了Android手写签名的实现方法,产品要求用户可以在app上签协议..所以得弄个手写签名版,参考了一些资料自己写了个PaintView去继承View,实现签名功能. package ...
Android电子手写签名
前言:最近一直在做h5,尼玛!!!前端真伤不起啊,由于刚接触,害怕兼容性啥的,导致我一个页面写了一天,泪崩啦-- 好吧,觉得得去撸一撸android才能平复的不安的小内心,刚好看到有一个这样的需求,需 ...
html5 移动端手写签名,H5移动端项目实现手写签名功能 vue实现手写签名
vue 移动端实现手写签名效果,功能很完美,保存时保存为base64格式. 刚好项目用到此功能,就网上找了一下,清理了无用代码,简单方便,因为项目中多个地方需要使用,所以我将它整理为组件,通过ref和 ...
H5移动端项目实现手写签名功能 vue实现手写签名
vue 移动端实现手写签名效果,功能很完美,保存时保存为base64格式. base64转file文件格式 vue中将base64转file文件格式刚好项目用到此功能,就网上找了一下,清理了无用代码 ...
vue canvas 方法无效_vue实现手机app手写签名功能
我曾经在一个文书交互相关的项目中遇到过这样的一个需求,当用户接收到管理员发送的文书时,用户需要在这个文书上签字签收,签名需要跟原有的文书进行合并,做到模仿线下真实签收的电子签名.这签收没有调用APP特 ...
Android屏幕手写签名的实现-详细篇
老规矩先看一下效果图 [实现思路] (1)创建画笔 private void init(Context context) {this.mContext = context;//设置抗锯齿mGestur ...

android 电子签名手写签名功能实现

android 电子签名手写签名功能实现相关推荐

最新文章

热门文章

android 电子签名 手写签名 功能实现

android 电子签名 手写签名 功能实现相关推荐

最新文章

热门文章

android 电子签名手写签名功能实现

android 电子签名手写签名功能实现相关推荐