Android實現九宮格解鎖的方法

相信大家都有使用九宮格解鎖，比如在設置手機安全項目中，可以使用九宮格解鎖，提高安全性，以及在使用支付功能的時候，為了提高安全使用九宮鎖，今天就為大家介紹Android實現九宮格的方法，分享給大家供大家參考。具體如下：
運行效果截圖如下：

具體代碼如下：

布局文件如下：

<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>

從布局文件中可以看出需要自定義一個View用於繪制九宮格圖案：
SudokuView.java

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; //默認的cell寬度
  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]; // 九宮格：定義用於存放九個數組

  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);

  /**
   * 下邊是三個構造方法：每一個構造方法中有一個初始化操作
   */
  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;
  }
}

MainActivity.java如下：

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);
  }
}

另外還需要一個存放圓圈的Javabean

package com.xuliugen.jiugongge;

/**
 * 代表每一個九宮格圓圈的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;
  }
}

像素轉換的工具類：

package com.xuliugen.jiugongge;

import android.content.Context;
/**
 * 手機屏幕px轉dp和dp轉px工具類 
 * @author xuliugenpc
 */
public class DensityUtil {

  private static float scale;

  /**
   * 根據手機的分辨率從 dp 的單位 轉成為 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);
  }

  /**
   * 根據手機的分辨率從 px(像素) 的單位 轉成為 dp
   */
  public static int px2dip(Context context, float pxValue) {
    if (scale == 0) {
      scale = context.getResources().getDisplayMetrics().density;
    }
    return (int) (pxValue / scale + 0.5f);
  }
}

以上就是Android實現九宮格解鎖的方法，希望本文所述對大家學習有所幫助。