前言
Android 自定義 View 技能是成為高級工程師所必備的，筆者覺得自定義 View 沒有什么捷徑可走，唯有經常練習才能解決產品需求。筆者也好久沒有寫自定義 View 了，趕緊寫個控件找點感覺回來。
本文實現的是一個 鎖屏圖案的自定義控件。效果圖如下：
Github 地址：AndroidSample
LockView 介紹
自定義屬性:
引用方式：
(1) 在布局文件中引入
<com.xing.androidsample.view.LockView android:id="@+id/lock_view" app:rowCount="4" app:normalColor="" app:moveColor="" app:errorColor="" android:layout_width="match_parent" android:layout_height="match_parent" android:layout_margin="40dp" />
(2) 在代碼中設置正確的圖案，用于校驗是否匹配成功，并在回調中獲取結果
List<Integer> intList = new ArrayList<>(); intList.add(3); intList.add(7); intList.add(4); intList.add(2); lockView.setStandard(intList); lockView.setOnDrawCompleteListener(new LockView.OnDrawCompleteListener() { @Override public void onComplete(boolean isSuccess) { Toast.makeText(CustomViewActivity.this, isSuccess ? "success" : "fail", Toast.LENGTH_SHORT).show(); } });實現思路
實現步驟
自定義屬性
在 res/values 目錄下新建 attrs.xml 文件：
<?xml version="1.0" encoding="utf-8"?><resources> <declare-styleable name="LockView"> <attr name="normalColor" format="color|reference" /> <!--默認圓顏色--> <attr name="moveColor" format="color|reference" /> <!--手指觸摸選中圓顏色--> <attr name="errorColor" format="color|reference" /> <!--手指抬起錯誤圓顏色--> <attr name="rowCount" format="integer" /> <!--每行每列圓的個數--> </declare-styleable></resources>
獲取自定義屬性
public LockView(Context context) { this(context, null); } public LockView(Context context, @Nullable AttributeSet attrs) { super(context, attrs); readAttrs(context, attrs); init(); } /** * 獲取自定義屬性 */ private void readAttrs(Context context, AttributeSet attrs) { TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.LockView); normalColor = typedArray.getColor(R.styleable.LockView_normalColor, DEFAULT_NORMAL_COLOR); moveColor = typedArray.getColor(R.styleable.LockView_moveColor, DEFAULT_MOVE_COLOR); errorColor = typedArray.getColor(R.styleable.LockView_errorColor, DEFAULT_ERROR_COLOR); rowCount = typedArray.getInteger(R.styleable.LockView_rowCount, DEFAULT_ROW_COUNT); typedArray.recycle(); } /** * 初始化 */ private void init() { stateSparseArray = new SparseIntArray(rowCount * rowCount); points = new PointF[rowCount * rowCount]; innerCirclePaint = new Paint(Paint.ANTI_ALIAS_FLAG); innerCirclePaint.setStyle(Paint.Style.FILL); outerCirclePaint = new Paint(Paint.ANTI_ALIAS_FLAG); outerCirclePaint.setStyle(Paint.Style.FILL); linePaint = new Paint(Paint.ANTI_ALIAS_FLAG); linePaint.setStyle(Paint.Style.STROKE); linePaint.setStrokeCap(Paint.Cap.ROUND); linePaint.setStrokeJoin(Paint.Join.ROUND); linePaint.setStrokeWidth(30); linePaint.setColor(moveColor); }計算圓的半徑
設定外圓半徑和相鄰兩圓之間間距相同，內圓半徑是外圓半徑的一半，所以半徑計算方式為：
radius = Math.min(w, h) / (2 * rowCount + rowCount - 1) * 1.0f;
設置各圓坐標
各圓坐標使用一維數組保存，計算方式為：
// 各個圓設置坐標點for (int i = 0; i < rowCount * rowCount; i++) { points[i] = new PointF(0, 0); points[i].set((i % rowCount * 3 + 1) * radius, (i / rowCount * 3 + 1) * radius);}測量 View 寬高
根據測量模式設置控件的寬高，當布局文件中設置的是 wrap_content ,默認將控件寬高設置為 600dp
@Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { super.onMeasure(widthMeasureSpec, heightMeasureSpec); int width = getSize(widthMeasureSpec); int height = getSize(heightMeasureSpec); setMeasuredDimension(width, height); } private int getSize(int measureSpec) { int mode = MeasureSpec.getMode(measureSpec); int size = MeasureSpec.getSize(measureSpec); if (mode == MeasureSpec.EXACTLY) { return size; } else if (mode == MeasureSpec.AT_MOST) { return Math.min(size, dp2Px(600)); } return dp2Px(600); }onTouchEvent() 觸摸事件
在手指滑動過程中，根據當前觸摸點坐標是否落在圓的范圍內，更新該圓的狀態，在重新繪制時，繪制成新的顏色。手指抬起時，將存放狀態的 list，選中圓的 list ，linePath 重置，并將結果回調出來。
private PointF touchPoint; @Override public boolean onTouchEvent(MotionEvent event) { switch (event.getAction()) { case MotionEvent.ACTION_DOWN: reset(); case MotionEvent.ACTION_MOVE: if (touchPoint == null) { touchPoint = new PointF(event.getX(), event.getY()); } else { touchPoint.set(event.getX(), event.getY()); } for (int i = 0; i < rowCount * rowCount; i++) { // 是否觸摸在圓的范圍內 if (getDistance(touchPoint, points[i]) < radius) { stateSparseArray.put(i, STATE_MOVE); if (!selectedList.contains(points[i])) { selectedList.add(points[i]); } break; } } break; case MotionEvent.ACTION_UP: if (check()) { // 正確圖案 if (listener != null) { listener.onComplete(true); } for (int i = 0; i < stateSparseArray.size(); i++) { int index = stateSparseArray.keyAt(i); stateSparseArray.put(index, STATE_MOVE); } } else { // 錯誤圖案 for (int i = 0; i < stateSparseArray.size(); i++) { int index = stateSparseArray.keyAt(i); stateSparseArray.put(index, STATE_ERROR); } linePaint.setColor(0xeeff0000); if (listener != null) { listener.onComplete(false); } } touchPoint = null; if (timer == null) { timer = new Timer(); } timer.schedule(new TimerTask() { @Override public void run() { linePath.reset(); linePaint.setColor(0xee0000ff); selectedList.clear(); stateSparseArray.clear(); postInvalidate(); } }, 1000); break; } invalidate(); return true; }繪制各圓和各圓之間連接線段
@Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); drawCircle(canvas); drawLinePath(canvas); } private void drawCircle(Canvas canvas) { // 依次從索引 0 到索引 8，根據不同狀態繪制圓點 for (int index = 0; index < rowCount * rowCount; index++) { int state = stateSparseArray.get(index); switch (state) { case STATE_NORMAL: innerCirclePaint.setColor(normalColor); outerCirclePaint.setColor(normalColor & 0x66ffffff); break; case STATE_MOVE: innerCirclePaint.setColor(moveColor); outerCirclePaint.setColor(moveColor & 0x66ffffff); break; case STATE_ERROR: innerCirclePaint.setColor(errorColor); outerCirclePaint.setColor(errorColor & 0x66ffffff); break; } canvas.drawCircle(points[index].x, points[index].y, radius, outerCirclePaint); canvas.drawCircle(points[index].x, points[index].y, radius / 2f, innerCirclePaint); } }完整 View 代碼：
/** * Created by star.tao on 2018/5/30. * email: xing-java@foxmail.com * github: https://github.com/xing16 */public class LockView extends View { private static final int DEFAULT_NORMAL_COLOR = 0xee776666; private static final int DEFAULT_MOVE_COLOR = 0xee0000ff; private static final int DEFAULT_ERROR_COLOR = 0xeeff0000; private static final int DEFAULT_ROW_COUNT = 3; private static final int STATE_NORMAL = 0; private static final int STATE_MOVE = 1; private static final int STATE_ERROR = 2; private int normalColor; // 無滑動默認顏色 private int moveColor; // 滑動選中顏色 private int errorColor; // 錯誤顏色 private float radius; // 外圓半徑 private int rowCount; private PointF[] points; // 一維數組記錄所有圓點的坐標點 private Paint innerCirclePaint; // 內圓畫筆 private Paint outerCirclePaint; // 外圓畫筆 private SparseIntArray stateSparseArray; private List<PointF> selectedList = new ArrayList<>(); private List<Integer> standardPointsIndexList = new ArrayList<>(); private Path linePath = new Path(); // 手指移動的路徑 private Paint linePaint; private Timer timer; public LockView(Context context) { this(context, null); } public LockView(Context context, @Nullable AttributeSet attrs) { super(context, attrs); readAttrs(context, attrs); init(); } private void readAttrs(Context context, AttributeSet attrs) { TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.LockView); normalColor = typedArray.getColor(R.styleable.LockView_normalColor, DEFAULT_NORMAL_COLOR); moveColor = typedArray.getColor(R.styleable.LockView_moveColor, DEFAULT_MOVE_COLOR); errorColor = typedArray.getColor(R.styleable.LockView_errorColor, DEFAULT_ERROR_COLOR); rowCount = typedArray.getInteger(R.styleable.LockView_rowCount, DEFAULT_ROW_COUNT); typedArray.recycle(); } private void init() { stateSparseArray = new SparseIntArray(rowCount * rowCount); points = new PointF[rowCount * rowCount]; innerCirclePaint = new Paint(Paint.ANTI_ALIAS_FLAG); innerCirclePaint.setStyle(Paint.Style.FILL); outerCirclePaint = new Paint(Paint.ANTI_ALIAS_FLAG); outerCirclePaint.setStyle(Paint.Style.FILL); linePaint = new Paint(Paint.ANTI_ALIAS_FLAG); linePaint.setStyle(Paint.Style.STROKE); linePaint.setStrokeCap(Paint.Cap.ROUND); linePaint.setStrokeJoin(Paint.Join.ROUND); linePaint.setStrokeWidth(30); linePaint.setColor(moveColor); } @Override protected void onSizeChanged(int w, int h, int oldw, int oldh) { super.onSizeChanged(w, h, oldw, oldh); // 外圓半徑 = 相鄰外圓之間間距 = 2倍內圓半徑 radius = Math.min(w, h) / (2 * rowCount + rowCount - 1) * 1.0f; // 各個圓設置坐標點 for (int i = 0; i < rowCount * rowCount; i++) { points[i] = new PointF(0, 0); points[i].set((i % rowCount * 3 + 1) * radius, (i / rowCount * 3 + 1) * radius); } } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { super.onMeasure(widthMeasureSpec, heightMeasureSpec); int width = getSize(widthMeasureSpec); int height = getSize(heightMeasureSpec); setMeasuredDimension(width, height); } private int getSize(int measureSpec) { int mode = MeasureSpec.getMode(measureSpec); int size = MeasureSpec.getSize(measureSpec); if (mode == MeasureSpec.EXACTLY) { return size; } else if (mode == MeasureSpec.AT_MOST) { return Math.min(size, dp2Px(600)); } return dp2Px(600); } @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); drawCircle(canvas); drawLinePath(canvas); } private void drawCircle(Canvas canvas) { // 依次從索引 0 到索引 8，根據不同狀態繪制圓點 for (int index = 0; index < rowCount * rowCount; index++) { int state = stateSparseArray.get(index); switch (state) { case STATE_NORMAL: innerCirclePaint.setColor(normalColor); outerCirclePaint.setColor(normalColor & 0x66ffffff); break; case STATE_MOVE: innerCirclePaint.setColor(moveColor); outerCirclePaint.setColor(moveColor & 0x66ffffff); break; case STATE_ERROR: innerCirclePaint.setColor(errorColor); outerCirclePaint.setColor(errorColor & 0x66ffffff); break; } canvas.drawCircle(points[index].x, points[index].y, radius, outerCirclePaint); canvas.drawCircle(points[index].x, points[index].y, radius / 2f, innerCirclePaint); } } /** * 繪制選中點之間相連的路徑 * * @param canvas */ private void drawLinePath(Canvas canvas) { // 重置linePath linePath.reset(); // 選中點個數大于 0 時，才繪制連接線段 if (selectedList.size() > 0) { // 起點移動到按下點位置 linePath.moveTo(selectedList.get(0).x, selectedList.get(0).y); for (int i = 1; i < selectedList.size(); i++) { linePath.lineTo(selectedList.get(i).x, selectedList.get(i).y); } // 手指抬起時，touchPoint設置為null,使得已經繪制游離的路徑，消失掉， if (touchPoint != null) { linePath.lineTo(touchPoint.x, touchPoint.y); } canvas.drawPath(linePath, linePaint); } } private PointF touchPoint; @Override public boolean onTouchEvent(MotionEvent event) { switch (event.getAction()) { case MotionEvent.ACTION_DOWN: reset(); case MotionEvent.ACTION_MOVE: if (touchPoint == null) { touchPoint = new PointF(event.getX(), event.getY()); } else { touchPoint.set(event.getX(), event.getY()); } for (int i = 0; i < rowCount * rowCount; i++) { // 是否觸摸在圓的范圍內 if (getDistance(touchPoint, points[i]) < radius) { stateSparseArray.put(i, STATE_MOVE); if (!selectedList.contains(points[i])) { selectedList.add(points[i]); } break; } } break; case MotionEvent.ACTION_UP: if (check()) { // 正確圖案 if (listener != null) { listener.onComplete(true); } for (int i = 0; i < stateSparseArray.size(); i++) { int index = stateSparseArray.keyAt(i); stateSparseArray.put(index, STATE_MOVE); } } else { // 錯誤圖案 for (int i = 0; i < stateSparseArray.size(); i++) { int index = stateSparseArray.keyAt(i); stateSparseArray.put(index, STATE_ERROR); } linePaint.setColor(0xeeff0000); if (listener != null) { listener.onComplete(false); } } touchPoint = null; if (timer == null) { timer = new Timer(); } timer.schedule(new TimerTask() { @Override public void run() { linePath.reset(); linePaint.setColor(0xee0000ff); selectedList.clear(); stateSparseArray.clear(); postInvalidate(); } }, 1000); break; } invalidate(); return true; } /** * 清除繪制圖案的條件，當觸發 invalidate() 時將清空圖案 */ private void reset() { touchPoint = null; linePath.reset(); linePaint.setColor(0xee0000ff); selectedList.clear(); stateSparseArray.clear(); } public void onStop() { timer.cancel(); } private boolean check() { if (selectedList.size() != standardPointsIndexList.size()) { return false; } for (int i = 0; i < standardPointsIndexList.size(); i++) { Integer index = standardPointsIndexList.get(i); if (points[index] != selectedList.get(i)) { return false; } } return true; } public void setStandard(List<Integer> pointsList) { if (pointsList == null) { throw new IllegalArgumentException("standard points index can't null"); } if (pointsList.size() > rowCount * rowCount) { throw new IllegalArgumentException("standard points index list can't large to rowcount * columncount"); } standardPointsIndexList = pointsList; } private OnDrawCompleteListener listener; public void setOnDrawCompleteListener(OnDrawCompleteListener listener) { this.listener = listener; } public interface OnDrawCompleteListener { void onComplete(boolean isSuccess); } private float getDistance(PointF centerPoint, PointF downPoint) { return (float) Math.sqrt(Math.pow(centerPoint.x - downPoint.x, 2) + Math.pow(centerPoint.y - downPoint.y, 2)); } private int dp2Px(int dpValue) { return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dpValue, getResources().getDisplayMetrics()); }}以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持VEVB武林網。
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