Android实现九宫格解锁

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:tools="http://schemas.android.com/tools"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 android:paddingBottom="@dimen/activity_vertical_margin"
 android:paddingLeft="@dimen/activity_horizontal_margin"
 android:paddingRight="@dimen/activity_horizontal_margin"
 android:paddingTop="@dimen/activity_vertical_margin"
 tools:context=".MainActivity" >

 <com.xuliugen.jiugongge.SudokuView
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:text="@string/hello_world" />

</RelativeLayout>

package com.xuliugen.jiugongge;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.widget.Toast;

public class SudokuView extends View {

 private static final int DEFALUT_CELL_WIDTH = 60; //默认的cell宽度
 private static final int DEFALUT_CELL_STROKE_WIDTH = 2;
 private static final int DEFALUT_SPACE = DEFALUT_CELL_WIDTH >> 1;

 private Cell mCells[] = new Cell[9]; // 九宫格：定义用于存放九个数组

 private int mCellWidth;
 private int mCellRadius;
 private int mCellStrokeWidth;
 private int mSpace;

 private Paint mPaintNormal;
 private Paint mPaintSelected;
 private int mWidth;
 private int mHeight;

 private float mCurrentX;
 private float mCurrentY;
 private boolean mFinish = false;

 private StringBuffer mSbSelected = new StringBuffer(20);

 /**
  * 下边是三个构造方法：每一个构造方法中有一个初始化操作
  */
 public SudokuView(Context context) {
  super(context);
  init();
 }

 public SudokuView(Context context, AttributeSet attrs) {
  super(context, attrs);
  init();
 }

 public SudokuView(Context context, AttributeSet attrs, int defStyleAttr) {
  super(context, attrs, defStyleAttr);
  init();
 }

 /**
  * 初始化操作
  */
 private void init() {
  mCellWidth = DensityUtil.dip2px(getContext(), DEFALUT_CELL_WIDTH);
  mCellRadius = DensityUtil.dip2px(getContext(), DEFALUT_CELL_WIDTH >> 1);
  mCellStrokeWidth = DensityUtil.dip2px(getContext(),
    DEFALUT_CELL_STROKE_WIDTH);
  mSpace = DensityUtil.dip2px(getContext(), DEFALUT_SPACE);

  mPaintNormal = new Paint();
  mPaintNormal.setColor(Color.WHITE);
  mPaintNormal.setStrokeWidth(mCellStrokeWidth);
  mPaintNormal.setStyle(Paint.Style.STROKE);
  mPaintNormal.setAntiAlias(true);

  mPaintSelected = new Paint();
  mPaintSelected.setColor(Color.CYAN);
  mPaintSelected.setStrokeWidth(mCellStrokeWidth);
  mPaintSelected.setStyle(Paint.Style.STROKE);
  mPaintSelected.setAntiAlias(true);

  Cell cell;
  float x;
  float y;

  for (int i = 0; i < 9; i++) {
   x = mSpace * (i % 3 + 1) + mCellRadius + mCellWidth * (i % 3);
   y = mSpace * (i / 3 + 1) + mCellRadius + mCellWidth * (i / 3);

   cell = new Cell(x, y);
   mCells[i] = cell;
  }
 }

 @Override
 protected void onDraw(Canvas canvas) {
  super.onDraw(canvas);
  drawCell(canvas);
  drawLine(canvas);
 }

 private void drawCell(Canvas canvas) {
  for (int i = 0; i < 9; i++) {
   canvas.drawCircle(mCells[i].getCenterX(), mCells[i].getCenterY(),
     mCellRadius, mCells[i].isSelected() ? mPaintSelected
       : mPaintNormal);
  }
 }

 private void drawLine(Canvas canvas) {
  if ("".equals(mSbSelected.toString())) {
   return;
  }

  String[] selectedIndexs = mSbSelected.toString().split(",");
  Cell cell = mCells[Integer.valueOf(selectedIndexs[0])];
  Cell nextCell;
  if (selectedIndexs.length > 1) {
   for (int i = 1; i < selectedIndexs.length; i++) {
    nextCell = mCells[Integer.valueOf(selectedIndexs[i])];
    canvas.drawLine(cell.getCenterX(), cell.getCenterY(),
      nextCell.getCenterX(), nextCell.getCenterY(),
      mPaintSelected);

    cell = nextCell;
   }
  }

  if (!mFinish) {
   canvas.drawLine(cell.getCenterX(), cell.getCenterY(), mCurrentX,
     mCurrentY, mPaintSelected);
  }
 }

 @Override
 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
  mWidth = getRealSize(widthMeasureSpec);
  mHeight = getRealSize(heightMeasureSpec);

  setMeasuredDimension(mWidth, mWidth);
 }

 private int getRealSize(int measureSpc) {
  int result;
  int mode = MeasureSpec.getMode(measureSpc);
  int size = MeasureSpec.getSize(measureSpc);

  if (mode == MeasureSpec.AT_MOST || mode == MeasureSpec.UNSPECIFIED) {
   result = mCellWidth * 3 + mSpace * 4;
  } else {
   result = size;
  }

  return result;
 }

 @Override
 public boolean onTouchEvent(MotionEvent event) {

  switch (event.getAction()) {
  case MotionEvent.ACTION_DOWN:
   if (mFinish) {
    for (int i = 0; i < 9; i++) {
     mCells[i].setSelected(false);
    }
    mFinish = false;
    mSbSelected.delete(0, mSbSelected.length());
    invalidate();
    return false;
   }
   handleDownEvent(event);
   break;
  case MotionEvent.ACTION_UP:
   mFinish = true;
   Toast.makeText(getContext(), mSbSelected.toString(),
     Toast.LENGTH_SHORT).show();
   break;
  case MotionEvent.ACTION_MOVE:
   handleMoveEvent(event);
   break;
  }

  return true;
 }

 private void handleMoveEvent(MotionEvent event) {
  int index = findCellIndex(event.getX(), event.getY());
  if (index != -1) {
   mCells[index].setSelected(true);
   mSbSelected.append(index).append(",");
  }
  invalidate();

  mCurrentX = event.getX();
  mCurrentY = event.getY();
 }

 private void handleDownEvent(MotionEvent event) {
  int index = findCellIndex(event.getX(), event.getY());
  if (index != -1) {
   mCells[index].setSelected(true);
   mSbSelected.append(index).append(",");
   invalidate();
  }

  mCurrentX = event.getX();
  mCurrentY = event.getY();
 }

 private int findCellIndex(float x, float y) {
  float cellX;
  float cellY;
  int result = -1;

  for (int i = 0; i < 9; i++) {
   if (mCells[i].isSelected()) {
    continue;
   }

   cellX = mCells[i].getCenterX();
   cellY = mCells[i].getCenterY();

   float tempX = cellX - x;
   float tempY = cellY - y;

   float distance = (float) Math.sqrt(tempX * tempX + tempY * tempY);

   if (distance < mCellRadius) {
    result = i;
    break;
   }
  }

  return result;
 }
}

package com.xuliugen.jiugongge;

import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.Menu;
import android.view.MenuItem;

public class MainActivity extends ActionBarActivity {

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
 }

 @Override
 public boolean onCreateOptionsMenu(Menu menu) {
  getMenuInflater().inflate(R.menu.menu_main, menu);
  return true;
 }

 @Override
 public boolean onOptionsItemSelected(MenuItem item) {
  int id = item.getItemId();

  if (id == R.id.action_settings) {
   return true;
  }
  return super.onOptionsItemSelected(item);
 }
}

package com.xuliugen.jiugongge;

/**
 * 代表每一个九宫格圆圈的Javabean
 * @author xuliugenpc
 */
public class Cell {
 private float centerX;
 private float centerY;
 private boolean selected;

 public Cell(float x, float y) {
  centerX = x;
  centerY = y;
 }

 public float getCenterX() {
  return centerX;
 }

 public void setCenterX(float centerX) {
  this.centerX = centerX;
 }

 public float getCenterY() {
  return centerY;
 }

 public void setCenterY(float centerY) {
  this.centerY = centerY;
 }

 public boolean isSelected() {
  return selected;
 }

 public void setSelected(boolean selected) {
  this.selected = selected;
 }
}

package com.xuliugen.jiugongge;

import android.content.Context;
/**
 * 手机屏幕px转dp和dp转px工具类 
 * @author xuliugenpc
 */
public class DensityUtil {

 private static float scale;

 /**
  * 根据手机的分辨率从 dp 的单位 转成为 px(像素)
  */
 public static int dip2px(Context context, float dpValue) {
  if (scale == 0) {
   scale = context.getResources().getDisplayMetrics().density;
  }
  return (int) (dpValue * scale + 0.5f);
 }

 /**
  * 根据手机的分辨率从 px(像素) 的单位 转成为 dp
  */
 public static int px2dip(Context context, float pxValue) {
  if (scale == 0) {
   scale = context.getResources().getDisplayMetrics().density;
  }
  return (int) (pxValue / scale + 0.5f);
 }
}