Android图形验证码的实现

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1.图片验证工具类：其中，在Default Settings中可以设置验证码图形的大小，验证码的长度，内边距，随机距离等可以根据需要进行调整。

package com.example.codedemo;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import java.util.Random;
/**
* Created by yao
* 用于图片验证码的工具类
*/
public class CodeUtils {
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 CodeUtils mCodeUtils;
private int mPaddingLeft, mPaddingTop;
private StringBuilder mBuilder = new StringBuilder();
private Random mRandom = new Random();
//Default Settings
private static final int DEFAULT_CODE_LENGTH = 6;//验证码的长度这里是6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 = 30;//左边距范围值
private static final int BASE_PADDING_TOP = 70;//上边距
private static final int RANGE_PADDING_TOP = 15;//上边距范围值
private static final int DEFAULT_WIDTH = 300;//默认宽度.图片的总宽
private static final int DEFAULT_HEIGHT = 100;//默认高度.图片的总高
private static final int DEFAULT_COLOR = 0xDF;//默认背景颜色值
private String code;
public static CodeUtils getInstance() {
if(mCodeUtils == null) {
mCodeUtils = new CodeUtils();
}
return mCodeUtils;
}
//生成验证码图片
public Bitmap createBitmap() {
mPaddingLeft = 0; //每次生成验证码图片时初始化
mPaddingTop = 0;
Bitmap bitmap = Bitmap.createBitmap(DEFAULT_WIDTH, DEFAULT_HEIGHT, Config.ARGB_8888);
Canvas canvas = new Canvas(bitmap);
code = createCode();
canvas.drawColor(Color.rgb(DEFAULT_COLOR, DEFAULT_COLOR, DEFAULT_COLOR));
Paint paint = new Paint();
paint.setTextSize(DEFAULT_FONT_SIZE);
for (int i = 0; i < code.length(); i++) {
randomTextStyle(paint);
randomPadding();
canvas.drawText(code.charAt(i) + "" , mPaddingLeft, mPaddingTop, paint);
}
//干扰线
for (int i = 0; i < DEFAULT_LINE_NUMBER; i++) {
drawLine(canvas, paint);
}
canvas.save(Canvas.ALL_SAVE_FLAG);//保存
canvas.restore();
return bitmap;
}
/**
* 得到图片中的验证码字符串
* @return
*/
public String getCode() {
return code;
}
//生成验证码
public String createCode() {
mBuilder.delete(0, mBuilder.length()); //使用之前首先清空内容
for (int i = 0; i < DEFAULT_CODE_LENGTH; i++) {
mBuilder.append(CHARS[mRandom.nextInt(CHARS.length)]);
}
return mBuilder.toString();
}
//生成干扰线
private void drawLine(Canvas canvas, Paint paint) {
int color = randomColor();
int startX = mRandom.nextInt(DEFAULT_WIDTH);
int startY = mRandom.nextInt(DEFAULT_HEIGHT);
int stopX = mRandom.nextInt(DEFAULT_WIDTH);
int stopY = mRandom.nextInt(DEFAULT_HEIGHT);
paint.setStrokeWidth(1);
paint.setColor(color);
canvas.drawLine(startX, startY, stopX, stopY, paint);
}
//随机颜色
private int randomColor() {
mBuilder.delete(0, mBuilder.length()); //使用之前首先清空内容
String haxString;
for (int i = 0; i < 3; i++) {
haxString = Integer.toHexString(mRandom.nextInt(0xFF));
if (haxString.length() == 1) {
haxString = "0" + haxString;
}
mBuilder.append(haxString);
}
return Color.parseColor("#" + mBuilder.toString());
}
//随机文本样式
private void randomTextStyle(Paint paint) {
int color = randomColor();
paint.setColor(color);
paint.setFakeBoldText(mRandom.nextBoolean()); //true为粗体，false为非粗体
float skewX = mRandom.nextInt(11) / 10;
skewX = mRandom.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为非下划线
// paint.setStrikeThruText(true); //true为删除线，false为非删除线
}
//随机间距
private void randomPadding() {
mPaddingLeft += BASE_PADDING_LEFT + mRandom.nextInt(RANGE_PADDING_LEFT);
mPaddingTop = BASE_PADDING_TOP + mRandom.nextInt(RANGE_PADDING_TOP);
}
}
2.使用时候的布局文件：
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="${relativePackage}.${activityClass}" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginLeft="10dp"
android:orientation="vertical">
<ImageView
android:id="@+id/image"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"
android:src="@drawable/ic_launcher"/>
<EditText
android:id="@+id/et"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"
android:hint="输入验证码"/>
<Button
android:id="@+id/btn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"
android:text="获得验证码"/>
<Button
android:id="@+id/btn_submit"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"
android:text="提交"/>
</LinearLayout>
</RelativeLayout>
3.使用的类中如何操作：
1. package com.example.codedemo;
3. import android.app.Activity;
4. import android.graphics.Bitmap;
5. import android.os.Bundle;
6. import android.text.TextUtils;
7. import android.util.Log;
8. import android.view.View;
9. import android.view.View.OnClickListener;
10. import android.widget.Button;
11. import android.widget.EditText;
12. import android.widget.ImageView;
13. import android.widget.Toast;
15. public class MainActivity extends Activity implements OnClickListener {
17. private ImageView image;
18. private EditText et;
19. private Button btn,submit;
20. private String codeStr;
21. private CodeUtils codeUtils;
23. @Override
24. protected void onCreate(Bundle savedInstanceState) {
25. super.onCreate(savedInstanceState);
26. setContentView(R.layout.activity_main);
28. initView();
30. }
32. private void initView() {
33. image = (ImageView) findViewById(R.id.image);
34. et = (EditText) findViewById(R.id.et);
35. btn = (Button) findViewById(R.id.btn);
36. submit = (Button) findViewById(R.id.btn_submit);
37. btn.setOnClickListener(this);
38. submit.setOnClickListener(this);
40. }
42. @Override
43. public void onClick(View v) {
44. switch (v.getId()) {
45. case R.id.btn:
46. codeUtils = CodeUtils.getInstance();
47. Bitmap bitmap = codeUtils.createBitmap();
48. image.setImageBitmap(bitmap);
50. break;
51. case R.id.btn_submit:
52. codeStr = et.getText().toString().trim();
53. Log.e("codeStr", codeStr);
54. if (null == codeStr || TextUtils.isEmpty(codeStr)) {
55. Toast.makeText(this, "请输入验证码", 0).show();
56. return;
57. }
58. String code = codeUtils.getCode();
59. Log.e("code", code);
60. if (code.equalsIgnoreCase(codeStr)) {
61. Toast.makeText(this, "验证码正确", 0).show();
62. } else {
63. Toast.makeText(this, "验证码错误", 0).show();
64. }
65. break;
66. default:
67. break;
68. }
70. }
71. }

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