本文源码(utf-8编码)：http://download.csdn.net/detail/weidi1989/6628211
ps:请不要再问我，为什么导入之后会乱码了。
其实，代码基本上都是从原生系统中提取的：LockPatternView、加密工具类，以及解锁逻辑等，我只是稍作修改，大家都知道，原生系统界面比较丑陋，因此，我特意把QQ的apk解压了，从中拿了几张图案解锁的图片，一个简单的例子就这样诞生了。
好了，废话不多说，我们来看看效果(最后两张是最新4.4系统，炫一下，呵呵)：
1.最关健的就是那个自定义九宫格View，代码来自framework下：LockPatternView，原生系统用的图片资源比较多，好像有7、8张吧，而且绘制的比较复杂，我找寻半天，眼睛都找瞎了，发现解压的QQ里面就3张图片，一个圈圈，两个点，没办法，只能修改代码了，在修改的过程中，才发现，其实可以把原生的LockPatternView给简化，绘制更少的图片，达到更好的效果。总共优化有：①去掉了连线的箭头，②原生的连线只有白色一种，改成根据不同状态显示黄色和红色两张色，③.原生view是先画点再画线，使得线覆盖在点的上面，影响美观，改成先画连线再画点。
关健部分代码onDraw函数：
@Override
protected void onDraw(Canvas canvas) {
final ArrayList<Cell> pattern = mPattern;
final int count = pattern.size();
final boolean[][] drawLookup = mPatternDrawLookup;
if (mPatternDisplayMode == DisplayMode.Animate) {
// figure out which circles to draw
// + 1 so we pause on complete pattern
final int oneCycle = (count + 1) * MILLIS_PER_CIRCLE_ANIMATING;
final int spotInCycle = (int) (SystemClock.elapsedRealtime() - mAnimatingPeriodStart)
% oneCycle;
final int numCircles = spotInCycle / MILLIS_PER_CIRCLE_ANIMATING;
clearPatternDrawLookup();
for (int i = 0; i < numCircles; i++) {
final Cell cell = pattern.get(i);
drawLookup[cell.getRow()][cell.getColumn()] = true;
}
// figure out in progress portion of ghosting line
final boolean needToUpdateInProgressPoint = numCircles > 0
&& numCircles < count;
if (needToUpdateInProgressPoint) {
final float percentageOfNextCircle = ((float) (spotInCycle % MILLIS_PER_CIRCLE_ANIMATING))
/ MILLIS_PER_CIRCLE_ANIMATING;
final Cell currentCell = pattern.get(numCircles - 1);
final float centerX = getCenterXForColumn(currentCell.column);
final float centerY = getCenterYForRow(currentCell.row);
final Cell nextCell = pattern.get(numCircles);
final float dx = percentageOfNextCircle
* (getCenterXForColumn(nextCell.column) - centerX);
final float dy = percentageOfNextCircle
* (getCenterYForRow(nextCell.row) - centerY);
mInProgressX = centerX + dx;
mInProgressY = centerY + dy;
}
// TODO: Infinite loop here...
invalidate();
}
final float squareWidth = mSquareWidth;
final float squareHeight = mSquareHeight;
float radius = (squareWidth * mDiameterFactor * 0.5f);
mPathPaint.setStrokeWidth(radius);
final Path currentPath = mCurrentPath;
currentPath.rewind();
// TODO: the path should be created and cached every time we hit-detect
// a cell
// only the last segment of the path should be computed here
// draw the path of the pattern (unless the user is in progress, and
// we are in stealth mode)
final boolean drawPath = (!mInStealthMode || mPatternDisplayMode == DisplayMode.Wrong);
// draw the arrows associated with the path (unless the user is in
// progress, and
// we are in stealth mode)
boolean oldFlag = (mPaint.getFlags() & Paint.FILTER_BITMAP_FLAG) != 0;
mPaint.setFilterBitmap(true); // draw with higher quality since we
// render with transforms
// draw the lines
if (drawPath) {
boolean anyCircles = false;
for (int i = 0; i < count; i++) {
Cell cell = pattern.get(i);
// only draw the part of the pattern stored in
// the lookup table (this is only different in the case
// of animation).
if (!drawLookup[cell.row][cell.column]) {
break;
}
anyCircles = true;
float centerX = getCenterXForColumn(cell.column);
float centerY = getCenterYForRow(cell.row);
if (i == 0) {
currentPath.moveTo(centerX, centerY);
} else {
currentPath.lineTo(centerX, centerY);
}
}
// add last in progress section
if ((mPatternInProgress || mPatternDisplayMode == DisplayMode.Animate)
&& anyCircles) {
currentPath.lineTo(mInProgressX, mInProgressY);
}
// chang the line color in different DisplayMode
if (mPatternDisplayMode == DisplayMode.Wrong)
mPathPaint.setColor(Color.RED);
else
mPathPaint.setColor(Color.YELLOW);
canvas.drawPath(currentPath, mPathPaint);
}
// draw the circles
final int paddingTop = getPaddingTop();
final int paddingLeft = getPaddingLeft();
for (int i = 0; i < 3; i++) {
float topY = paddingTop + i * squareHeight;
// float centerY = mPaddingTop + i * mSquareHeight + (mSquareHeight
// / 2);
for (int j = 0; j < 3; j++) {
float leftX = paddingLeft + j * squareWidth;
drawCircle(canvas, (int) leftX, (int) topY, drawLookup[i][j]);
}
}
mPaint.setFilterBitmap(oldFlag); // restore default flag
}2.第二个值得学习的地方是(代码来自设置应用中)：在创建解锁图案时的枚举使用，原生代码中使用了很多枚举，将绘制图案时的状态、底部两个按钮状态、顶部一个TextView显示的提示文字都紧密的联系起来。因此，只用监听LockPatternView动态变化，对应改变底部Button和顶部TextView的状态即可实现联动，简单的方法可以实现很多代码才能实现的逻辑，个人很喜欢。
①全局的状态：
/**
* Keep track internally of where the user is in choosing a pattern.
*/
protected enum Stage {
// 初始状态
Introduction(R.string.lockpattern_recording_intro_header,
LeftButtonMode.Cancel, RightButtonMode.ContinueDisabled,
ID_EMPTY_MESSAGE, true),
// 帮助状态
HelpScreen(R.string.lockpattern_settings_help_how_to_record,
LeftButtonMode.Gone, RightButtonMode.Ok, ID_EMPTY_MESSAGE,
false),
// 绘制过短
ChoiceTooShort(R.string.lockpattern_recording_incorrect_too_short,
LeftButtonMode.Retry, RightButtonMode.ContinueDisabled,
ID_EMPTY_MESSAGE, true),
// 第一次绘制图案
FirstChoiceValid(R.string.lockpattern_pattern_entered_header,
LeftButtonMode.Retry, RightButtonMode.Continue,
ID_EMPTY_MESSAGE, false),
// 需要再次绘制确认
NeedToConfirm(R.string.lockpattern_need_to_confirm,
LeftButtonMode.Cancel, RightButtonMode.ConfirmDisabled,
ID_EMPTY_MESSAGE, true),
// 确认出错
ConfirmWrong(R.string.lockpattern_need_to_unlock_wrong,
LeftButtonMode.Cancel, RightButtonMode.ConfirmDisabled,
ID_EMPTY_MESSAGE, true),
// 选择确认
ChoiceConfirmed(R.string.lockpattern_pattern_confirmed_header,
LeftButtonMode.Cancel, RightButtonMode.Confirm,
ID_EMPTY_MESSAGE, false);
/**
* @param headerMessage
* The message displayed at the top.
* @param leftMode
* The mode of the left button.
* @param rightMode
* The mode of the right button.
* @param footerMessage
* The footer message.
* @param patternEnabled
* Whether the pattern widget is enabled.
*/
Stage(int headerMessage, LeftButtonMode leftMode,
RightButtonMode rightMode, int footerMessage,
boolean patternEnabled) {
this.headerMessage = headerMessage;
this.leftMode = leftMode;
this.rightMode = rightMode;
this.footerMessage = footerMessage;
this.patternEnabled = patternEnabled;
}
final int headerMessage;
final LeftButtonMode leftMode;
final RightButtonMode rightMode;
final int footerMessage;
final boolean patternEnabled;
}②.底部两个按钮的状态枚举：
/**
* The states of the left footer button.
*/
enum LeftButtonMode {
// 取消
Cancel(android.R.string.cancel, true),
// 取消时禁用
CancelDisabled(android.R.string.cancel, false),
// 重试
Retry(R.string.lockpattern_retry_button_text, true),
// 重试时禁用
RetryDisabled(R.string.lockpattern_retry_button_text, false),
// 消失
Gone(ID_EMPTY_MESSAGE, false);
/**
* @param text
* The displayed text for this mode.
* @param enabled
* Whether the button should be enabled.
*/
LeftButtonMode(int text, boolean enabled) {
this.text = text;
this.enabled = enabled;
}
final int text;
final boolean enabled;
}
/**
* The states of the right button.
*/
enum RightButtonMode {
// 继续
Continue(R.string.lockpattern_continue_button_text, true),
//继续时禁用
ContinueDisabled(R.string.lockpattern_continue_button_text, false),
//确认
Confirm(R.string.lockpattern_confirm_button_text, true),
//确认是禁用
ConfirmDisabled(R.string.lockpattern_confirm_button_text, false),
//OK
Ok(android.R.string.ok, true);
/**
* @param text
* The displayed text for this mode.
* @param enabled
* Whether the button should be enabled.
*/
RightButtonMode(int text, boolean enabled) {
this.text = text;
this.enabled = enabled;
}
final int text;
final boolean enabled;
}就这样，只要LockPatternView的状态一发生改变，就会动态改变底部两个Button的文字和状态。很简洁，逻辑性很强。
3.第三个个人觉得比较有用的就是加密这一块了，为了以后方便使用，我把图案加密和字符加密分成两个工具类：LockPatternUtils和LockPasswordUtils两个文件，本文使用到的是LockPatternUtils。其实所谓的图案加密也是将其通过SHA-1加密转化成二进制数再保存到文件中(原生系统保存在/system/目录下，我这里没有权限，就保存到本应用目录下)，解密时，也是将获取到用户的输入通过同样的方法加密，再与保存到文件中的对比，相同则密码正确，不同则密码错误。关健代码就是以下4个函数：
/**
* Serialize a pattern. 加密
*
* @param pattern
* The pattern.
* @return The pattern in string form.
*/
public static String patternToString(List<LockPatternView.Cell> pattern) {
if (pattern == null) {
return "";
}
final int patternSize = pattern.size();
byte[] res = new byte[patternSize];
for (int i = 0; i < patternSize; i++) {
LockPatternView.Cell cell = pattern.get(i);
res[i] = (byte) (cell.getRow() * 3 + cell.getColumn());
}
return new String(res);
}
/**
* Save a lock pattern.
*
* @param pattern
* The new pattern to save.
* @param isFallback
* Specifies if this is a fallback to biometric weak
*/
public void saveLockPattern(List<LockPatternView.Cell> pattern) {
// Compute the hash
final byte[] hash = LockPatternUtils.patternToHash(pattern);
try {
// Write the hash to file
RandomAccessFile raf = new RandomAccessFile(sLockPatternFilename,
"rwd");
// Truncate the file if pattern is null, to clear the lock
if (pattern == null) {
raf.setLength(0);
} else {
raf.write(hash, 0, hash.length);
}
raf.close();
} catch (FileNotFoundException fnfe) {
// Cant do much, unless we want to fail over to using the settings
// provider
Log.e(TAG, "Unable to save lock pattern to " + sLockPatternFilename);
} catch (IOException ioe) {
// Cant do much
Log.e(TAG, "Unable to save lock pattern to " + sLockPatternFilename);
}
}
/*
* Generate an SHA-1 hash for the pattern. Not the most secure, but it is at
* least a second level of protection. First level is that the file is in a
* location only readable by the system process.
*
* @param pattern the gesture pattern.
*
* @return the hash of the pattern in a byte array.
*/
private static byte[] patternToHash(List<LockPatternView.Cell> pattern) {
if (pattern == null) {
return null;
}
final int patternSize = pattern.size();
byte[] res = new byte[patternSize];
for (int i = 0; i < patternSize; i++) {
LockPatternView.Cell cell = pattern.get(i);
res[i] = (byte) (cell.getRow() * 3 + cell.getColumn());
}
try {
MessageDigest md = MessageDigest.getInstance("SHA-1");
byte[] hash = md.digest(res);
return hash;
} catch (NoSuchAlgorithmException nsa) {
return res;
}
}
/**
* Check to see if a pattern matches the saved pattern. If no pattern
* exists, always returns true.
*
* @param pattern
* The pattern to check.
* @return Whether the pattern matches the stored one.
*/
public boolean checkPattern(List<LockPatternView.Cell> pattern) {
try {
// Read all the bytes from the file
RandomAccessFile raf = new RandomAccessFile(sLockPatternFilename,
"r");
final byte[] stored = new byte[(int) raf.length()];
int got = raf.read(stored, 0, stored.length);
raf.close();
if (got <= 0) {
return true;
}
// Compare the hash from the file with the entered pattern's hash
return Arrays.equals(stored,
LockPatternUtils.patternToHash(pattern));
} catch (FileNotFoundException fnfe) {
return true;
} catch (IOException ioe) {
return true;
}
}好了，代码就分析到这里，非常感谢你看到了文章末尾，很晚了，睡觉去，如果大家有什么问题或建议，欢迎留言，一起讨论，谢谢！
作者：weidi1989 发表于2013-11-29 0:39:24 原文链接
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