Android开发中验证码的生成

近期在做电商金融类的项目，验证码的生成方法不可缺少。先学习了一种。经过測试好用。从别处学习的代码，稍修改了一下可选择是否支持识别大写和小写。直接上代码。

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.Toast;

public class VerifyCodeActivity extends Activity {

private ImageView vc_image; // 验证码图标
private String getCode = null; // 获取验证码的值
private EditText vc_code; // 文本框的值

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.verifycode);
vc_image = (ImageView) findViewById(R.id.verify_imv);
vc_code = (EditText) findViewById(R.id.myedit);
getCode = SecurityCode.getInstance().getCode(false); // 获取显示的验证码
findViewById(R.id.vc_shuaxin).setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
vc_image.setImageBitmap(SecurityCode.getInstance().getBitmap());
getCode = SecurityCode.getInstance().getCode(false);
}
});
findViewById(R.id.verfiy).setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
String verfiyString = vc_code.getText().toString();
if (verfiyString.equals(getCode)) {
Toast.makeText(getApplicationContext(), "验证码输入正确", Toast.LENGTH_LONG).show();
} else {
Toast.makeText(getApplicationContext(), "验证码输入错误", Toast.LENGTH_LONG).show();
}
}
});
}
}

import java.util.Locale;
import java.util.Random;

import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;

/**
* @Description:验证码生成类
*/
public class SecurityCode {

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', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 'A', 'B', 'C', 'D', 'E', 'F', 'G',
'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z' };

private static SecurityCode bpUtil;

public static SecurityCode getInstance() {
if (bpUtil == null)
bpUtil = new SecurityCode();
return bpUtil;
}

// default settings
private static final int DEFAULT_CODE_LENGTH = 4;// 验证码的长度 这里是4位
private static final int DEFAULT_FONT_SIZE = 60;// 字体大小
private static final int DEFAULT_LINE_NUMBER = 3;// 多少条干扰线
private static final int BASE_PADDING_LEFT = 20; // 左边距
private static final int RANGE_PADDING_LEFT = 35;// 左边距范围值
private static final int BASE_PADDING_TOP = 42;// 上边距
private static final int RANGE_PADDING_TOP = 15;// 上边距范围值
private static final int DEFAULT_WIDTH = 200;// 默认宽度.图片的总宽
private static final int DEFAULT_HEIGHT = 70;// 默认高度.图片的总高
private final int DEFAULT_COLOR = 0xdf;// 默认背景颜色值

// settings decided by the layout xml
// canvas width and height
private int width = DEFAULT_WIDTH;
private int height = DEFAULT_HEIGHT;

// random word space and pading_top
private int base_padding_left = BASE_PADDING_LEFT;
private int range_padding_left = RANGE_PADDING_LEFT;
private int base_padding_top = BASE_PADDING_TOP;
private int range_padding_top = RANGE_PADDING_TOP;

// number of chars, lines; font size
private int codeLength = DEFAULT_CODE_LENGTH;
private int line_number = DEFAULT_LINE_NUMBER;
private int font_size = DEFAULT_FONT_SIZE;

// variables
private String code;// 保存生成的验证码
private int padding_left, padding_top;
private Random random = new Random();

private Bitmap createBitmap() {
padding_left = 0;

Bitmap bp = Bitmap.createBitmap(width, height, Config.ARGB_8888);
Canvas c = new Canvas(bp);

code = createCode();

c.drawColor(Color.rgb(DEFAULT_COLOR, DEFAULT_COLOR, DEFAULT_COLOR));
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;
}

/**
* @Description:是否区分大写和小写
*/
public String getCode(boolean isMatchCase) {
if (isMatchCase) {
if (code != null) {
code.toLowerCase(Locale.getDefault());
}
} else {
return code;
}

return null;
}

public Bitmap getBitmap() {
return createBitmap();
}

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类型參数。负数表示右斜。整数左斜
// paint.setUnderlineText(true); //true为下划线。false为非下划线
// paint.setStrikeThruText(true); //true为删除线。false为非删除线
}

private void randomPadding() {
padding_left += base_padding_left + random.nextInt(range_padding_left);
padding_top = base_padding_top + random.nextInt(range_padding_top);
}
}

布局文件
<?

xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:orientation="vertical" >
<ImageView

android:id="@+id/verify_imv"

android:layout_width="wrap_content"

android:layout_height="wrap_content" />
<Button

android:id="@+id/vc_shuaxin"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="获取验证码" />
<EditText

android:id="@+id/myedit"

android:layout_width="200dp"

android:layout_height="wrap_content"

android:hint="请输入验证码" />
<Button

android:id="@+id/verfiy"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="验证输入的验证码是否正确" />
</LinearLayout>