本文主要是介绍Android 实现涂鸦笔效果，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！
1、主要可以通过手指绘制各种图案、还可以清除回撤等效果，实现比较简单。
2、主要实现代码，功能实现比较简单。
package com.example.mytestproject;import android.content.Context;
import android.graphics.BlurMaskFilter;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import androidx.annotation.Nullable;
import java.util.ArrayList;
import java.util.List;public class DrawView extends View {public float mCurrentX = 40;public float mCurrentY = 50;private float mDownX;private float mDownY;private Paint mPaint;private Line mCurrentLine = new Line();private ArrayList<Line> lines = new ArrayList<>();private float mLastMoveX = 0;private float mLastMoveY = 0;private int mSpace;private Matrix mMatrix;private Drawable[] mDrawables = new Drawable[3];private List<Line> mCheLines = new ArrayList<>();private int mResetPosition = 0;public DrawView(Context context) {this(context, null);}public DrawView(Context context, @Nullable AttributeSet attrs) {this(context, attrs, 0);}public DrawView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {super(context, attrs, defStyleAttr);// mPaint.setShader(new BitmapShader(mBitmap, Shader.TileMode.CLAMP, Shader.TileMode.MIRROR));
// BlurMaskFilter maskFilter = new BlurMaskFilter(10, BlurMaskFilter.Blur.NORMAL);
// mPaint.setMaskFilter(maskFilter);//Shader shader0 = new BitmapShader(mBitmap, Shader.TileMode.REPEAT, Shader.TileMode.REPEAT);
// Shader shader = new LinearGradient(0, 0, 30, 0, new int[]{Color.WHITE, Color.RED, Color.RED}, new float[]{0f, 0.5f, 1f}, Shader.TileMode.REPEAT);
// Shader shader1 = new RadialGradient(10, 10, 10, new int[]{Color.GREEN, Color.WHITE, Color.GREEN}, new float[]{0, 0.5f, 1}, Shader.TileMode.MIRROR);
// Shader shader2 = new SweepGradient(15, 15, Color.RED, Color.BLUE);
// Shader shader3 = new ComposeShader(shader, shader1, PorterDuff.Mode.MULTIPLY);
// mMatrix = new Matrix();
// mLinearGradient.setLocalMatrix(mMatrix);// mPaint.setShader(shader);BlurMaskFilter PaintBGBlur = new BlurMaskFilter(10, BlurMaskFilter.Blur.SOLID);mPaint = new Paint();mPaint.setStyle(Paint.Style.STROKE);mPaint.setStrokeCap(Paint.Cap.ROUND);mPaint.setMaskFilter(PaintBGBlur);//mPaint.setAntiAlias(true);mPaint.setColor(Color.RED);mDrawables[0] = getResources().getDrawable(R.mipmap.star_big_off);mDrawables[1] = getResources().getDrawable(R.mipmap.star_big_on);mDrawables[2] = getResources().getDrawable(R.mipmap.rate_star_med_on_holo_light);mSpace = mDrawables[0].getIntrinsicWidth();mPaint.setStrokeWidth(mDrawables[0].getIntrinsicWidth());}@Overrideprotected void onDraw(Canvas canvas) {super.onDraw(canvas);for (int i = 0; i < lines.size(); i++) {drawLine(canvas, lines.get(i));}drawLine(canvas, mCurrentLine);}private void drawLine(Canvas canvas, Line line) {for (int i = 0; i < line.points.size() - 1; i++) {float x = line.points.get(i).x;float y = line.points.get(i).y;int size = mDrawables.length;int surplus = i%size;for (int j=0;j<size;j++){if (surplus==j){mDrawables[j].setBounds((int) x, (int) y, (int) x + mDrawables[j].getIntrinsicWidth(), (int) y + mDrawables[j].getIntrinsicHeight());mDrawables[j].draw(canvas);break;}}}}@Overridepublic boolean onTouchEvent(MotionEvent event) {switch (event.getAction()) {case MotionEvent.ACTION_DOWN:mDownX = event.getX();mDownY = event.getY();mLastMoveX = mDownX;mLastMoveY = mDownY;break;case MotionEvent.ACTION_MOVE:mCurrentX = event.getX();mCurrentY = event.getY();if (Math.abs(mCurrentX - mLastMoveX) > mSpace || Math.abs(mCurrentY - mLastMoveY) > mSpace) {ViewPoint point = new ViewPoint();point.x = mCurrentX;point.y = mCurrentY;mCurrentLine.points.add(point);mLastMoveX = mCurrentX;mLastMoveY = mCurrentY;}break;case MotionEvent.ACTION_UP:lines.add(mCurrentLine);mCheLines.add(mCurrentLine);mCurrentLine = new Line();mResetPosition = mCheLines.size();break;}invalidate();return true;}public void last() {mResetPosition--;if (mResetPosition <= 0) {mResetPosition = 0;}lines.clear();for (int i = 0; i < mResetPosition; i++) {lines.add(mCheLines.get(i));}invalidate();}public void next() {mResetPosition++;if (mResetPosition >= mCheLines.size()) {mResetPosition = mCheLines.size();}lines.clear();for (int i = 0; i < mResetPosition; i++) {lines.add(mCheLines.get(i));}invalidate();}public void clear() {mCheLines.clear();lines.clear();mCurrentLine.points.clear();invalidate();}
}
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