验证码

import java.util.Random;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.Bitmap.Config;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;

public class ValidateImageView extends View {

    private String TAG = "ValidateImageView";
    private Paint paint = new Paint();
    /*
     * 验证码内容
     */
    private String[] content = null;
    /*
     * 验证码图片
     */
    private Bitmap bitmap = null;

    public ValidateImageView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    public void draw(Canvas canvas) {
        // TODO Auto-generated method stub
        if (bitmap != null) {
            canvas.drawBitmap(bitmap, 0, 0, paint);
        } else {
            paint.setColor(Color.GRAY);
            paint.setTextSize(20);
            canvas.drawText("点击换一换", 10, 30, paint);
        }
        super.draw(canvas);
    }

    /**
     * 得到验证码；设置图片
     * @param strContent 验证码的字符串数组
     * @return
     */
    public String[] getValidataAndSetImage(String[] strContent) {
        content = strContent;
        //产生随机数，并返回
        String [] strRes = generageRadom(strContent);
        Log.i(TAG, "generate validate code: " + strRes[0] + strRes[1] + strRes[2] + strRes[3]);
//      String strRes = generageRadomStr(strContent);
        //传随机串和随机数
        bitmap = generateValidate(content,strRes);
        invalidate();

        return strRes;
    }

    private Bitmap generateValidate(String[] strContent,String [] strRes) {
        int width = 120,height = 50;

        int isRes = isStrContent(strContent);
        if (isRes == 0) {
            return null;
        }

        Bitmap sourceBitmap = Bitmap.createBitmap(width, height, Config.ARGB_8888);
        Canvas canvas = new Canvas(sourceBitmap);
        Paint p = new Paint();
        p.setTextSize(height / 2);
        p.setFakeBoldText(true);

        p.setColor(getRandColor(200, 230, 170));
        canvas.drawText(strRes[0], 10, height / 2, p);
        Matrix m1 = new Matrix();
        m1.setRotate(15);
        canvas.setMatrix(m1);

        p.setColor(getRandColor(200, 230, 170));
        canvas.drawText(strRes[1], 40, height / 2, p);
        m1.setRotate(10);
        canvas.setMatrix(m1);

        p.setColor(getRandColor(200, 230, 170));
        canvas.drawText(strRes[2], 70, height / 2 - 10, p);
        m1.setRotate(15);
        canvas.setMatrix(m1);

        p.setColor(getRandColor(200, 230, 170));
        canvas.drawText(strRes[3], 100, height / 2 - 15, p);
        m1.setRotate(20);
        canvas.setMatrix(m1);

        //障碍设置
        int startX = 0,startY = 0,stopX = 0,stopY = 0;
        for (int i = 0; i < 55; i++) {
            startX = pointRadom(width);
            startY = pointRadom(height);
            stopX = pointRadom(15);
            stopY = pointRadom(15);
            p.setColor(getRandColor(200, 230, 220));
            canvas.drawLine(startX, startY - 20, startX + stopX, startY + stopY - 20, p);
        }

        canvas.save();
        return sourceBitmap;
    }

    private int isStrContent(String[] strContent) {
        if (strContent == null || strContent.length <= 0) {
            return 0;
        } else {
            return 1;
        }
    }

    /**
     * 从指定数组中随机取出4个字符(数组)
     * @param strContent
     * @return
     */
    private String[] generageRadom(String[] strContent){
        String[] str = new String[4];
        // 随机串的个数
        int count = strContent.length;
        // 生成4个随机数
        Random random = new Random();
        int randomResFirst = random.nextInt(count);
        int randomResSecond = random.nextInt(count);
        int randomResThird = random.nextInt(count);
        int randomResFourth = random.nextInt(count);

        str[0] = strContent[randomResFirst].toString().trim();
        str[1] = strContent[randomResSecond].toString().trim();
        str[2] = strContent[randomResThird].toString().trim();
        str[3] = strContent[randomResFourth].toString().trim();
        return str;
    }

    /**
     * 从指定数组中随机取出4个字符(字符串)
     * @param strContent
     * @return
     */
    private String generageRadomStr(String[] strContent){
        StringBuilder str = new StringBuilder();
        // 随机串的个数
        int count = strContent.length;
        // 生成4个随机数
        Random random = new Random();
        int randomResFirst = random.nextInt(count);
        int randomResSecond = random.nextInt(count);
        int randomResThird = random.nextInt(count);
        int randomResFourth = random.nextInt(count);

        str.append(strContent[randomResFirst].toString().trim());
        str.append(strContent[randomResSecond].toString().trim());
        str.append(strContent[randomResThird].toString().trim());
        str.append(strContent[randomResFourth].toString().trim());
        return str.toString();
    }

    private int pointRadom(int n){
        Random r = new Random();
        return r.nextInt(n);
    }

    /**
     * 给定范围获得随机颜色
     *
     * @param rc
     *            0-255
     * @param gc
     *            0-255
     * @param bc
     *            0-255
     * @return colorValue 颜色值，使用setColor(colorValue)
     */
    public int getRandColor(int rc, int gc, int bc) {
        Random random = new Random();
        if (rc > 255)
            rc = 255;
        if (gc > 255)
            gc = 255;
        if (bc > 255)
            bc = 255;
        int r = rc + random.nextInt(rc);
        int g = gc + random.nextInt(gc);
        int b = bc + random.nextInt(bc);
        return Color.rgb(r, g, b);
    }

}