android画板控件

2023-03-27 02:34| 来源: 网络整理| 查看: 265

这段时间做了几个自定义控件，整理到博客上供大家参考，先看下画板效果图：

这个画板很简单，但基本的功能都具有了，橡皮擦，清除，撤销，反撤销，保存。想要实现更多的功能，比如说更改画笔颜色，大小等等功能，继续往上加代码就可以了。实现这个画板的逻辑很简单，就是自定义一个画板控件，下面看下主要的代码：

public class DrawingBoardView extends View { // 画图的模式（默认是画笔） private DrawMode mDrawMode = DrawMode.PaintMode; // 画笔 private Paint mPaint; // 画笔颜色 private int mPaintColor = Color.RED; // 画笔宽度 private int mPaintSize = diptopx(5); // 橡皮擦的宽度 private int mEraserSize = diptopx(36); // 缓冲的位图 private Bitmap mBufferBitmap; // 缓冲的画布 private Canvas mBufferCanvas; // 当前控件的宽 private int mWidth; // 当前控件的高 private int mHight; // 画布的颜色 private int mCanvasColor = Color.WHITE; // 上次的位置 private float mLastX; private float mLastY; // 路径 private Path mPath; // 设置图形混合模式为清除 private PorterDuffXfermode mEraserMode = new PorterDuffXfermode(PorterDuff.Mode.DST_OUT); // 保存的路径 private List savePaths; // 当前的路径 private List currPaths; // 最多保存20条路径 private int MAX_PATH = 20; public DrawingBoardView(Context context) { this(context, null); } public DrawingBoardView(Context context, AttributeSet attrs) { this(context, attrs, 0); } public DrawingBoardView(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); initPath(); initPaint(); } /** * 初始化路径 */ private void initPath() { mPath = new Path(); savePaths = new ArrayList(); currPaths = new ArrayList(); } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { super.onMeasure(widthMeasureSpec, heightMeasureSpec); mWidth = MeasureSpec.getSize(widthMeasureSpec); mHight = MeasureSpec.getSize(heightMeasureSpec); setMeasuredDimension(mWidth, mHight); initCanvas(); } /** * 初始化缓冲画布 */ private void initCanvas() { // 创建一个BITMAP mBufferBitmap = Bitmap.createBitmap(mWidth, mHight, Bitmap.Config.ARGB_8888); // 创建一个画布，所有mBufferCanvas画的东西都被保存在了mBufferBitmap中 mBufferCanvas = new Canvas(mBufferBitmap); // 设置画布颜色 mBufferCanvas.drawColor(mCanvasColor); } /** * 初始化画笔 */ private void initPaint() { // 设置画笔抗锯齿和抖动 mPaint = new Paint(Paint.ANTI_ALIAS_FLAG | Paint.DITHER_FLAG); // 画笔只描边 mPaint.setStyle(Paint.Style.STROKE); // 设置画笔颜色 mPaint.setColor(mPaintColor); // 设置画笔宽度 mPaint.setStrokeWidth(mPaintSize); // 设置圆形线帽 mPaint.setStrokeJoin(Paint.Join.ROUND); // 设置线段连接处圆角 mPaint.setStrokeCap(Paint.Cap.ROUND); } @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); canvas.drawBitmap(mBufferBitmap, 0, 0, null); } @Override public boolean onTouchEvent(MotionEvent event) { float x = event.getX(); float y = event.getY(); switch (event.getAction()) { case MotionEvent.ACTION_DOWN: mLastX = x; mLastY = y; mPath.moveTo(mLastX, mLastY); break; case MotionEvent.ACTION_MOVE: // 画出路径 mPath.quadTo(mLastX, mLastY, (mLastX + x) / 2, (mLastY + y) / 2); mBufferCanvas.drawPath(mPath, mPaint); invalidate(); mLastX = x; mLastY = y; break; case MotionEvent.ACTION_UP: // 保存路径 saveDrawPaths(); mPath.reset(); break; } return true; } /** * 保存画的路径 */ private void saveDrawPaths() { if (savePaths.size() == MAX_PATH) { savePaths.remove(0); } savePaths.clear(); savePaths.addAll(currPaths); Path cachePath = new Path(mPath); Paint cachePaint = new Paint(mPaint); savePaths.add(new DrawPathInfo(cachePaint, cachePath)); currPaths.add(new DrawPathInfo(cachePaint, cachePath)); } public int diptopx(float dipValue) { final float scale = this.getResources().getDisplayMetrics().density; return (int) (dipValue * scale + 0.5f); } /** * 擦除画布 */ public void clean() { savePaths.clear(); currPaths.clear(); // 把位图擦成透明的 mBufferBitmap.eraseColor(Color.TRANSPARENT); invalidate(); } /** * 设置画笔模式 * * @param mode */ public void setMode(DrawMode mode) { if (mode != mDrawMode) { if (mode == DrawMode.EraserMode) { mPaint.setStrokeWidth(mEraserSize); mPaint.setXfermode(mEraserMode); mPaint.setColor(mCanvasColor); } else { mPaint.setXfermode(null); mPaint.setColor(mPaintColor); mPaint.setStrokeWidth(mPaintSize); } mDrawMode = mode; } } /** * 获取当前模式 * * @return */ public DrawMode getMode() { return mDrawMode; } /** * 上一步撤销 */ public void lastStep() { if (currPaths.size() > 0) { currPaths.remove(currPaths.size() - 1); redrawBitmap(); } } /** * 下一步凡撤销 */ public void nextStep() { if (currPaths != savePaths) { if (savePaths.size() > currPaths.size()) { currPaths.add(savePaths.get(currPaths.size())); redrawBitmap(); } } } /** * 重绘位图 */ private void redrawBitmap() { mBufferBitmap.eraseColor(Color.TRANSPARENT); for (int i = 0; i < currPaths.size(); i++) { DrawPathInfo path = currPaths.get(i); mBufferCanvas.drawPath(path.getPath(), path.getPaint()); } invalidate(); } /** * 保存图片 */ public void save() { mBufferCanvas.save(Canvas.ALL_SAVE_FLAG); mBufferCanvas.restore(); String path = Environment.getExternalStorageDirectory().getPath(); //存储路径 File appDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES); if (appDir == null) { return; } String fileName = System.currentTimeMillis() + ".jpg"; File file = new File(appDir, fileName); try { FileOutputStream fileOutputStream = new FileOutputStream(file); mBufferBitmap.compress(Bitmap.CompressFormat.JPEG, 100, fileOutputStream); fileOutputStream.close(); Toast.makeText(getContext(), "保存成功", Toast.LENGTH_SHORT).show(); } catch (Exception e) { e.printStackTrace(); } } }

源码已上传到GitHub，欢迎fark,star点击查看GitHub源码

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android画板控件

android画板控件

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