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 pointContainer;//存储九个点的坐标
private List pointerSlipped;//存储得到的九宫格密码
public List getPointerSlipped() {
return pointerSlipped;
}
public void setPointerSlipped(List 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
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：
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
android:layout_width="match_parent"
android:layout_height="match_parent"/>
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。
