Android中圖案解鎖

首先要理解圖案的實現原理，上一張圖： 由上圖，可以看出，圖案中手勢的記錄是1-9或0-8的，保存的順序就是密碼，當然有些是可以重復的，為了安全，肯定不能直接存原順序，一定是要加密處理的，如MD5或Hash散列。 （作者： a day a better） 圖案解鎖中自定義View,是其中最為關鍵的一部分。下面是自定義LockView的實現，裡面的注釋寫的很詳細了。

package com.example.patternlock;

import java.util.ArrayList;
import java.util.List;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;

public class LockView extends View {
	private boolean inited = false;
	Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);// 抗鋸齒
	Paint pressPaint = new Paint(); //按下時的畫筆
	Paint errorPaint = new Paint(); //錯誤時的畫筆
	private Bitmap bitmapPointError;
	private Bitmap bitmapPointPress;
	private Bitmap bitmapPointNormal;
	private float bitmapR; // 點的半徑
	private boolean isDraw = false; //是否正在繪制
	float mouseX, mouseY;
	private Point [][] points = new Point[3][3];
	private ArrayList pointList = new ArrayList(); //保存經過的點
	private ArrayList passList = new ArrayList();
	private OnDrawFinishedListener listener;

	public LockView(Context context, AttributeSet attrs, int defStyleAttr) {
		super(context, attrs, defStyleAttr);
		// TODO Auto-generated constructor stub
	}

	public LockView(Context context, AttributeSet attrs) {
		super(context, attrs);
		// TODO Auto-generated constructor stub
	}

	public LockView(Context context) {
		super(context);
		// TODO Auto-generated constructor stub
	}

	@Override
	public boolean onTouchEvent(MotionEvent event) {
		mouseX = event.getX();
		mouseY = event.getY();
		int [] ij;
		int i , j;
		switch (event.getAction()) {
		case MotionEvent.ACTION_DOWN:
			resetPoints();
			ij = getSelectedPoint();
			if(ij != null){
				isDraw = true;
				i = ij[0];
				j = ij[1];
				points[i][j].state = Point.STATE_PRESS;
				pointList.add(points[i][j]);
				passList.add(i * 3 + j);
			}
			break;
		case MotionEvent.ACTION_MOVE:
			if(isDraw){
				ij = getSelectedPoint();
				if(ij != null){
					i = ij[0];
					j = ij[1];
					if(!pointList.contains(points[i][j])){
						points[i][j].state = Point.STATE_PRESS;
						pointList.add(points[i][j]);
						passList.add(i * 3 + j);
					}				
				}
			}
			break;
		case MotionEvent.ACTION_UP:
			boolean valid = false;
			if(listener != null && isDraw){
				valid = listener.OnDrawFinished(passList);
			}
			if(!valid){
				for (Point p:pointList) {
					p.state = Point.STATE_ERROR;
				}
			}
			isDraw = false;
			break;

		default:
			break;
		}
		this.postInvalidate();
		return true;
	}

	private int[] getSelectedPoint() {
		Point pMouse = new Point(mouseX,mouseY);
		for (int i = 0; i < points.length; i++) {
			for (int j = 0; j < points[i].length; j++) {
				if(points[i][j].distance(pMouse) < bitmapR){
					int [] result = new int [2];
					result[0] = i;
					result[1] = j;
					return result;
				}
			}
			
		}
		return null;
	}

	public void resetPoints() {
		passList.clear();
		pointList.clear();
		for (int i = 0; i < points.length; i++)
        {
            for (int j = 0; j < points[i].length; j++)
            {
                points[i][j].state = Point.STATE_NORMOL;
            }
        }
		this.postInvalidate();
	}

	@Override
	protected void onDraw(Canvas canvas) {
		
		super.onDraw(canvas);
		if(!inited){
			init();
		}
		drawPoints(canvas);
		
		if(pointList.size() > 0){ //畫線 2->3,3->5 ...
			Point a = pointList.get(0);
			for (int i = 1;i < pointList.size(); i++)
            {
                Point b = pointList.get(i);
                drawLine(canvas, a, b);
                a = b;
            }
			if(isDraw){ // 	畫最後一個點
				drawLine(canvas, a, new Point(mouseX, mouseY));
			}
		}
	}

	private void drawLine(Canvas canvas, Point a, Point b) {
		if(a.state == Point.STATE_ERROR){
			canvas.drawLine(a.x, a.y, b.x, b.y, errorPaint);
		}
		else if(a.state == Point.STATE_PRESS){
			canvas.drawLine(a.x, a.y, b.x, b.y, pressPaint);
		}
	}

	private void drawPoints(Canvas canvas) {
		for (int i = 0; i < points.length; i++) {
			for (int j = 0; j < points[i].length; j++) {
				if(points[i][j].state == Point.STATE_NORMOL){
					// normol
					canvas.drawBitmap(bitmapPointNormal, points[i][j].x - bitmapR, points[i][j].y - bitmapR, paint);
				}
				else if(points[i][j].state == Point.STATE_PRESS){
					// press
					canvas.drawBitmap(bitmapPointPress, points[i][j].x - bitmapR, points[i][j].y - bitmapR, paint);
				}
				else{
					// error
					canvas.drawBitmap(bitmapPointError, points[i][j].x - bitmapR, points[i][j].y - bitmapR, paint);
				}
			}
			
		}
	}

	private void init() {
		pressPaint.setColor(Color.YELLOW);
		pressPaint.setStrokeWidth(4);
		errorPaint.setColor(Color.RED);
		errorPaint.setStrokeWidth(4);
		
		bitmapPointError = BitmapFactory.decodeResource(getResources(), R.drawable.error);
		bitmapPointNormal = BitmapFactory.decodeResource(getResources(), R.drawable.normal);
		bitmapPointPress = BitmapFactory.decodeResource(getResources(), R.drawable.press);
		
		bitmapR = bitmapPointError.getWidth() / 2; //三種點的大小一樣
		int width = getWidth();
		int height = getHeight();
		int offset = Math.abs(width - height) / 2;
		int offsetX, offsetY;
		int space;
		if(width > height){
			space = height / 4;
			offsetX = offset;
			offsetY = 0;
		}
		else{
			space = width / 4;
			offsetX = 0;
			offsetY = offset;
		}
		points[0][0] = new Point(offsetX +space , offsetY + space);
		points[0][1] = new Point(offsetX + 2*space , offsetY + space);
		points[0][2] = new Point(offsetX + 3 * space , offsetY + space);
		points[1][0] = new Point(offsetX +space, offsetY + 2 * space);
		points[1][1] = new Point(offsetX + 2 * space , offsetY + 2 * space);
		points[1][2] = new Point(offsetX + 3 * space , offsetY + 2 * space);
		points[2][0] = new Point(offsetX +space, offsetY + 3 * space);
		points[2][1] = new Point(offsetX + 2 * space , offsetY + 3 * space);
		points[2][2] = new Point(offsetX + 3 * space , offsetY + 3 * space);
		
		inited = true; //初始化完成
	}
	
	public interface OnDrawFinishedListener{
		boolean OnDrawFinished(List passList);
	}
	
	public void setOnDrawFinishedListener(OnDrawFinishedListener listener){
		this.listener = listener;
	}
	

}

設置密碼：

package com.jikexueyuan.screenlock;

import android.content.Intent;
import android.content.SharedPreferences;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

import java.util.List;


public class SettingActivity extends ActionBarActivity {

    List passList;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_setting);
        final GestureLock lock = (GestureLock)findViewById(R.id.LockView);
        Button btn_reset = (Button)findViewById(R.id.btn_reset);
        Button btn_save = (Button)findViewById(R.id.btn_save);

        lock.setOnDrawFinishedListener(new GestureLock.OnDrawFinishedListener() {
            @Override
            public boolean OnDrawFinished(List passList) {
                if (passList.size() < 3)
                {
                    Toast.makeText(SettingActivity.this, 密碼不能少於3個點, Toast.LENGTH_SHORT).show();
                    return false;
                }
                else {
                    SettingActivity.this.passList = passList;
                    return true;
                }
            }
        });

        btn_reset.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                lock.resetPoints();
            }
        });

        btn_save.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (passList != null)
                {
                    StringBuilder sb = new StringBuilder();
                    for (Integer i : passList)
                    {
                        sb.append(i);
                    }
                    SharedPreferences sp = SettingActivity.this.getSharedPreferences(password, SettingActivity.this.MODE_PRIVATE);
                    SharedPreferences.Editor editor = sp.edit();
                    editor.putString(password, sb.toString());
                    editor.commit();

                    Toast.makeText(SettingActivity.this, 保存完成, Toast.LENGTH_SHORT).show();
                }
            }
        });
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_setting, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

檢驗密碼：

package com.example.patternlock;

import android.app.Activity;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.widget.Toast;

import java.util.List;

import com.example.patternlock.LockView.OnDrawFinishedListener;


public class LockActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_lock);
        SharedPreferences sp = getSharedPreferences(password, this.MODE_PRIVATE);
        final String password = sp.getString(password, );

        LockView lock = (LockView)findViewById(R.id.LockView);
        lock.setOnDrawFinishedListener(new OnDrawFinishedListener() {
            @Override
            public boolean OnDrawFinished(List passList) {
                StringBuilder sb = new StringBuilder();
                for (Integer i : passList)
                {
                    sb.append(i);
                }
                if (sb.toString().equals(password)){
                    Toast.makeText(LockActivity.this, 正確, Toast.LENGTH_SHORT).show();
                    return true;
                }
                else
                {
                    Toast.makeText(LockActivity.this, 錯誤, Toast.LENGTH_SHORT).show();
                    return false;
                }
            }
        });
    }
}