本文概述：

 滑动解锁九宫格的分析：

1、需要自定义控件；
2、需要重写事件onTouchEvent();
3、需要给九个点设置序号和坐标，这里用Map类就行；
4、需要判断是否到滑到过九点之一，并存储滑到过的点的序号，而且需要一个方法可以返回它们，这里用List类就行；

滑动解锁当前还是比较流行的，今天写了个简单的滑动解锁九宫格的例程，分享出来让初学者看看。

我的是这样的：

Demo

首先，自定义一个View

/** * 九宫格 */public class NineGridView extends View {  private int width;//该控件的宽  private int height;//该控件的高  private Paint mPaintBigCircle;//用于画外圆  private Paint mPaintSmallCircle;//用于画内圆  private Paint mPaintLine;//用于画线  private Paint mPaintText;//用于画文本  private Path path;//手势划线时需要用到它  private Map<Integer, Float[]> pointContainer;//存储九个点的坐标  private List<Integer> pointerSlipped;//存储得到的九宫格密码  public List<Integer> getPointerSlipped() {    return pointerSlipped;  }  public void setPointerSlipped(List<Integer> pointerSlipped) {    this.pointerSlipped = pointerSlipped;  }  public NineGridView(Context context) {    super(context);  }  public NineGridView(Context context, AttributeSet attrs) {    super(context, attrs);    mPaintBigCircle = new Paint();    mPaintBigCircle.setColor(Color.BLUE);    mPaintBigCircle.setStyle(Paint.Style.STROKE);//不充满    mPaintBigCircle.setAntiAlias(true);//抗锯齿打开    mPaintSmallCircle = new Paint();    mPaintSmallCircle.setColor(Color.GREEN);    mPaintSmallCircle.setStyle(Paint.Style.FILL);//充满，即画的几何体为实心    mPaintSmallCircle.setAntiAlias(true);    mPaintLine = new Paint();    mPaintLine.setColor(Color.GREEN);    mPaintLine.setStyle(Paint.Style.STROKE);    mPaintLine.setStrokeWidth(20);    mPaintLine.setAntiAlias(true);    mPaintText = new Paint();    mPaintText.setColor(Color.WHITE);    mPaintText.setTextAlign(Paint.Align.CENTER);//向中央对齐    mPaintText.setTextSize(50);    mPaintText.setAntiAlias(true);    path = new Path();    pointContainer = new HashMap<>();    pointerSlipped = new ArrayList<>();  }  @Override  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {    super.onMeasure(widthMeasureSpec, heightMeasureSpec);    width = getDefaultSize(getSuggestedMinimumWidth(), widthMeasureSpec);    height = getDefaultSize(getSuggestedMinimumHeight(), heightMeasureSpec);  }  private float pivotX;//触屏得到的x坐标  private float pivotY;//触屏得到的y坐标  private float selectedX;//当前选中的圆点的x坐标  private float selectedY;//当前选中的圆点的y坐标  private float selectedXOld;//从前选中的圆点的x坐标  private float selectedYOld;//从前选中的圆点的y坐标  private boolean isHasMoved = false;//用于判断path是否调用过moveTo()方法  @Override  public boolean onTouchEvent(MotionEvent event) {    switch (event.getAction()) {      case MotionEvent.ACTION_DOWN:        pivotX = event.getX();        pivotY = event.getY();        //每次触屏时需要清空一下pointerSlipped，即重置密码        pointerSlipped.clear();        Log.d("pointTouched", pivotX + "," + pivotY);        getSelectedPointIndex(pivotX, pivotY);        invalidate();//重绘        break;      case MotionEvent.ACTION_MOVE:        pivotX = event.getX();        pivotY = event.getY();        getSelectedPointIndex(pivotX, pivotY);        invalidate();        break;      case MotionEvent.ACTION_UP:        /**         * 当手指离开屏幕时，重置path         */        path.reset();        isHasMoved = false;        String indexSequence = "";        //打印出上一次手势密码的值        for(int index:pointerSlipped){          indexSequence += "/"+index;        }        Log.d("index",indexSequence);        break;    }    invalidate();    return true;  }  /**   * 得到并存储经过的圆点的序号   * @param pivotX   * @param pivotY   */  private void getSelectedPointIndex(float pivotX, float pivotY) {    int index = 0;    if (pivotX > patternMargin && pivotX < patternMargin + bigCircleRadius * 2) {      if (pivotY > height / 2 && pivotY < height / 2 + bigCircleRadius * 2) {        selectedX = pointContainer.get(1)[0];        selectedY = pointContainer.get(1)[1];        index = 1;        Log.d("selectedPoint", selectedX + "," + selectedY);      } else if (pivotY > height / 2 + added && pivotY < height / 2 + added + bigCircleRadius * 2) {        selectedX = pointContainer.get(4)[0];        selectedY = pointContainer.get(4)[1];        index = 4;      } else if (pivotY > height / 2 + added * 2 && pivotY < height / 2 + added * 2 + bigCircleRadius * 2) {        selectedX = pointContainer.get(7)[0];        selectedY = pointContainer.get(7)[1];        index = 7;      }    } else if (pivotX > patternMargin + added && pivotX < patternMargin + added + bigCircleRadius * 2) {      if (pivotY > height / 2 && pivotY < height / 2 + bigCircleRadius * 2) {        selectedX = pointContainer.get(2)[0];        selectedY = pointContainer.get(2)[1];        index = 2;      } else if (pivotY > height / 2 + added && pivotY < height / 2 + added + bigCircleRadius * 2) {        selectedX = pointContainer.get(5)[0];        selectedY = pointContainer.get(5)[1];        index = 5;      } else if (pivotY > height / 2 + added * 2 && pivotY <height / 2 + added * 2 + bigCircleRadius * 2) {        selectedX = pointContainer.get(8)[0];        selectedY = pointContainer.get(8)[1];        index = 8;      }    } else if (pivotX > patternMargin + added * 2 && pivotX < patternMargin + added * 2 + bigCircleRadius * 2) {      if (pivotY > height / 2 && pivotY < height / 2 + bigCircleRadius * 2) {        selectedX = pointContainer.get(3)[0];        selectedY = pointContainer.get(3)[1];        index = 3;      } else if (pivotY > height / 2 + added && pivotY < height / 2 + added + bigCircleRadius * 2) {        selectedX = pointContainer.get(6)[0];        selectedY = pointContainer.get(6)[1];        index = 6;      } else if (pivotY > height / 2 + added * 2 && pivotY < height / 2 + added * 2 + bigCircleRadius * 2) {        selectedX = pointContainer.get(9)[0];        selectedY = pointContainer.get(9)[1];        index = 9;      }    }    if (selectedX!=selectedXOld||selectedY!=selectedYOld){      //当这次的坐标与上次的坐标不同时存储这次点序号      pointerSlipped.add(index);      selectedXOld = selectedX;      selectedYOld = selectedY;      if (!isHasMoved){        //当第一次触碰到九个点之一时，path调用moveTo;        path.moveTo(selectedX,selectedY);        isHasMoved = true;      }else{        //path移动至当前圆点坐标        path.lineTo(selectedX,selectedY);      }    }  }  private String text = "请绘制解锁图案";  private float x;//绘制的圆形的x坐标  private float y;//绘制圆形的纵坐标  private float added;//水平竖直方向每个圆点中心间距  private float patternMargin = 100;//九宫格距离边界距离  private float bigCircleRadius = 90;//外圆半径  private float smallCircleRadius = 25;//内圆半径  private int index;//圆点的序号  @Override  protected void onDraw(Canvas canvas) {    super.onDraw(canvas);    added = (width - patternMargin * 2) / 3;    x = patternMargin + added / 2;    y = added / 2 + height / 2;    index = 1;    canvas.drawColor(Color.BLACK);    canvas.drawText(text, width / 2, height / 4, mPaintText);    /**     * 绘制九个圆点图案     */    for (int column = 0; column < 3; column++) {      for (int row = 0; row < 3; row++) {        canvas.drawCircle(x, y, bigCircleRadius, mPaintBigCircle);        canvas.drawCircle(x, y, smallCircleRadius, mPaintSmallCircle);        pointContainer.put(index, new Float[]{x, y});        index++;        x += added;      }      y += added;      x = patternMargin + added / 2;    }    x = patternMargin + added / 2;    y = added / 2 + height / 2;    canvas.drawPath(path, mPaintLine);  }}

为什么要规避重复？

因为在触屏时，会调用很多次onTouchEvent()方法，这样存储的手势密码肯定会不准确，我在以上代码中作出了处理，已经避免了重复，看打印信息：

这里写图片描述

显然，密码没有相邻数重复，当然还有一种情况就是手指在两个点之间来回等问题，这种状况也需要避免，这里没有作处理。当然，我做得还不够。。。

自定义view中用到的dp和px互相转换的工具类：

public class SizeConvert {  /**   * 将dp转换为sp   */  public static int dip2px(Context context, float dipValue){    final float scale = context.getResources().getDisplayMetrics().density;    return (int)(dipValue * scale + 0.5f);  }  /**   * sp转dp   */  public static int px2dip(Context context, float pxValue){    final float scale = context.getResources().getDisplayMetrics().density;    return (int)(pxValue / scale + 0.5f);  }}

主活动：

public class NineGridActivity extends BaseActivity{  @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.view_nine_grid);  }}

layout中的布局文件view_nine_grid：

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"       android:orientation="vertical"       android:layout_width="match_parent"       android:layout_height="match_parent">  <com.test.shiweiwei.myproject.selfish_view.NineGridView    android:layout_width="match_parent"    android:layout_height="match_parent"/></LinearLayout>

总结

我写的只是最基本的九宫格滑动解密项目，实际用的九宫格解密比这个要复杂，有许多特效和其他更严谨的处理，事件的处理也不是这样草草了事，如果想写得漂亮，还得多花工夫。