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Android之登录那点事

发布时间:2015-11-07 12:00:09
随着互联网的高速发展,一个应用为了保护用户的隐私,通常会通过设置用户名+密码的验证方式保证用户隐私的相对安全,我知道一般网站的登录验证,通常会设置一个二维码,通过验证二维码,防止恶意软件通过机械程序,对用户密码进行破解,那么Android设备如何实现这个功能呢?相信很多开发者对此 ...

  随着互联网的高速发展,一个应用为了保护用户的隐私,通常会通过设置用户名+密码的验证方式保证用户隐私的相对安全,我知道一般网站的登录验证,通常会设置一个二维码,通过验证二维码,防止恶意软件通过机械程序,对用户密码进行破解,那么Android设备如何实现这个功能呢?相信很多开发者对此不屑一顾,因为这样增加了用户使用的复杂性,很多软件是不会这样设计的,现在我们暂且不谈它是不是有用,今天我们重点探讨一下,如何在Android的设备上实现这个功能。本篇为大家介绍的内容包括:1、用户连续多次输错密码,增加验证码验证;2、Android如何通过http请求达到与服务器之间的通讯。好了下面开始我们今天内容的介绍,首先我们先一起来学习一下如何实现用户连续多次输错密码,增加验证码功能。

  既然用的到二维码,那么Android如何生成二维码呢?为大家提供一个生成二维码的类:

//生成二维码的类public class BPUtil {    /**   * 用于生成二维码的字符   */  private static final char[] CHARS = {    '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',    'a','b','c','d','e','f','g','h','i','j','k','m','l','n','o','p','q','r','s','t','u','v','w','x','y','z',    'A','B','C','D','E','F','G','H','I','J','K','M','L','N','O','P','Q','R','S','T','U','V','W','X','Y','Z'  };    private static BPUtil bpUtil;    public static BPUtil getInstance() {    if(bpUtil == null)      bpUtil = new BPUtil();    return bpUtil;  }  //      width="60" height="30" //       base_padding_left="5"//      range_padding_left="10"//      base_padding_top="15"//      range_padding_top="10"//      codeLength="4"//      line_number="3"//      font_size="20"     //default settings  private static final int DEFAULT_CODE_LENGTH = 4;  private static final int DEFAULT_FONT_SIZE = 20;  private static final int DEFAULT_LINE_NUMBER = 3;  private static final int BASE_PADDING_LEFT = 5, RANGE_PADDING_LEFT = 10, BASE_PADDING_TOP = 15, RANGE_PADDING_TOP = 10;  private static final int DEFAULT_WIDTH = 60, DEFAULT_HEIGHT = 30;    //settings decided by the layout //canvas width and height  private int width = DEFAULT_WIDTH, height = DEFAULT_HEIGHT;     //random word space and pading_top  private int base_padding_left = BASE_PADDING_LEFT, range_padding_left = RANGE_PADDING_LEFT,       base_padding_top = BASE_PADDING_TOP, range_padding_top = RANGE_PADDING_TOP;    //number of chars, lines; font size  private int codeLength = DEFAULT_CODE_LENGTH, line_number = DEFAULT_LINE_NUMBER, font_size = DEFAULT_FONT_SIZE;    //variables  private String code;  private int padding_left, padding_top;  private Random random = new Random();    public Bitmap createBitmap() {    padding_left = 0;        Bitmap bp = Bitmap.createBitmap(width, height, Config.ARGB_8888);     Canvas c = new Canvas(bp);    code = createCode();        c.drawColor(Color.WHITE);    Paint paint = new Paint();    paint.setTextSize(font_size);        for (int i = 0; i < code.length(); i++) {      randomTextStyle(paint);      randomPadding();      c.drawText(code.charAt(i) + "", padding_left, padding_top, paint);    }    for (int i = 0; i < line_number; i++) {      drawLine(c, paint);    }        c.save( Canvas.ALL_SAVE_FLAG );//保存     c.restore();//    return bp;  }    public String getCode() {     return bpUtil.createCode();  }    private String createCode() {    StringBuilder buffer = new StringBuilder();    for (int i = 0; i < codeLength; i++) {      buffer.append(CHARS[random.nextInt(CHARS.length)]);    }    return buffer.toString();  }    private void drawLine(Canvas canvas, Paint paint) {    int color = randomColor();    int startX = random.nextInt(width);    int startY = random.nextInt(height);    int stopX = random.nextInt(width);    int stopY = random.nextInt(height);    paint.setStrokeWidth(1);    paint.setColor(color);    canvas.drawLine(startX, startY, stopX, stopY, paint);  }    private int randomColor() {    return randomColor(1);  }  private int randomColor(int rate) {    int red = random.nextInt(256) / rate;    int green = random.nextInt(256) / rate;    int blue = random.nextInt(256) / rate;    return Color.rgb(red, green, blue);  }    private void randomTextStyle(Paint paint) {    int color = randomColor();    paint.setColor(color);    paint.setFakeBoldText(random.nextBoolean()); //true为粗体,false为非粗体    float skewX = random.nextInt(11) / 10;    skewX = random.nextBoolean() ? skewX : -skewX;    paint.setTextSkewX(skewX); //float类型参数,负数表示右斜,整数左斜//    paint.setUnderlineText(true); //true为下划线,false为非下划//    paint.setStrikeThruText(true); //true为删除线,false为非删除  }    private void randomPadding() {    padding_left += base_padding_left + random.nextInt(range_padding_left);    padding_top = base_padding_top + random.nextInt(range_padding_top);  }}

原标题:Android之登录那点事

关键词:Android

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