Android Studio实现图形验证码

源代码
源代码MainActivity
效果图32行需要修改，不修改会报错：需要常量表达式，我的代码已修改

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MainActivity

import static com.example.graphicverificationcode.RxCaptcha.TYPE.NUMBER;import android.annotation.SuppressLint;
import android.os.Bundle;
import android.view.View;
import android.widget.ImageView;
import android.widget.TextView;import androidx.appcompat.app.AppCompatActivity;public class MainActivity extends AppCompatActivity implements View.OnClickListener {TextView tvCode;ImageView ivCode;@SuppressLint("MissingInflatedId")@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);tvCode = findViewById(R.id.tv_code);ivCode = findViewById(R.id.iv_code);ivCode.setOnClickListener(this);}@Overridepublic void onClick(View view) {if (view.getId() == R.id.iv_code) {RxCaptcha.build().backColor(0xffffff).codeLength(4).fontSize(60).lineNumber(2).size(200, 70).type(NUMBER).into(ivCode);tvCode.setText(RxCaptcha.build().getCode());}}
}

RxCaptcha

import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.widget.ImageView;import java.util.Random;/*** 随机生成验证码，使用方法：* <p>* 拿到验证码图片ImageView* mIvCode.setImageBitmap(RxCaptcha.getInstance().createBitmap());* int code=RxCaptcha.getInstance().getCode();* <p>* 只需生成验证码值 String** <p/>* RxCaptcha** @version 1.0.0*/
public class RxCaptcha {public static RxCaptcha build() {if (rxCaptcha == null) {rxCaptcha = new RxCaptcha();}return rxCaptcha;}private static final char[] CHARS_NUMBER = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9'};private static final char[] CHARS_LETTER = {'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 final char[] CHARS_ALL = {'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 RxCaptcha rxCaptcha;private TYPE type = TYPE.CHARS;public enum TYPE{NUMBER,LETTER,CHARS}private RxCaptcha() {}private RxCaptcha(TYPE types) {this.type = types;}public static RxCaptcha getInstance(TYPE types) {if (rxCaptcha == null) {rxCaptcha = new RxCaptcha(types);}return rxCaptcha;}// default settingsprivate 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 = 0;// 多少条干扰线private static final int BASE_PADDING_LEFT = 20; // 左边距private static final int RANGE_PADDING_LEFT = 20;// 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 int DEFAULT_WIDTH = 200;// 默认宽度.图片的总宽private static int DEFAULT_HEIGHT = 70;// 默认高度.图片的总高private int DEFAULT_COLOR = 0xdf;// 默认背景颜色值// settings decided by the layout xml// canvas width and heightprivate int width = DEFAULT_WIDTH;private int height = DEFAULT_HEIGHT;// random word space and pading_topprivate 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 sizeprivate int codeLength = DEFAULT_CODE_LENGTH;private int line_number = DEFAULT_LINE_NUMBER;private int font_size = DEFAULT_FONT_SIZE;// variablesprivate String code;// 保存生成的验证码private int padding_left, padding_top;private Random random = new Random();/*** @param length 验证码的长度* @return*/public RxCaptcha codeLength(int length) {codeLength = length;return rxCaptcha;}/*** @param size 字体大小* @return*/public RxCaptcha fontSize(int size) {font_size = size;return rxCaptcha;}/*** @param number 干扰线 数量* @return*/public RxCaptcha lineNumber(int number) {line_number = number;return rxCaptcha;}/*** @return 背景颜色值*/public RxCaptcha backColor(int colorInt) {DEFAULT_COLOR = colorInt;return rxCaptcha;}public RxCaptcha type(TYPE type) {this.type = type;return rxCaptcha;}public RxCaptcha size(int width, int height) {this.width = width;this.height = height;return rxCaptcha;}private Bitmap makeBitmap() {padding_left = 0;Bitmap bp = Bitmap.createBitmap(width, height, Config.ARGB_8888);Canvas c = new Canvas(bp);code = makeCode();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();// 保存c.restore();//return bp;}public String getCode() {return code.toLowerCase();}public Bitmap into(ImageView imageView){Bitmap bitmap = createBitmap();if (imageView != null) {imageView.setImageBitmap(bitmap);}return bitmap;}public String createCode() {return makeCode();}private Bitmap mBitmapCode;public Bitmap createBitmap() {mBitmapCode = makeBitmap();return mBitmapCode;}private String makeCode() {StringBuilder buffer = new StringBuilder();switch (type) {case NUMBER:for (int i = 0; i < codeLength; i++) {buffer.append(CHARS_NUMBER[random.nextInt(CHARS_NUMBER.length)]);}break;case LETTER:for (int i = 0; i < codeLength; i++) {buffer.append(CHARS_LETTER[random.nextInt(CHARS_LETTER.length)]);}break;case CHARS:for (int i = 0; i < codeLength; i++) {buffer.append(CHARS_ALL[random.nextInt(CHARS_ALL.length)]);}break;default:for (int i = 0; i < codeLength; i++) {buffer.append(CHARS_ALL[random.nextInt(CHARS_ALL.length)]);}break;}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);}
}

activity_main.xml

<LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android"xmlns:tools="http://schemas.android.com/tools"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_margin="20dp"android:background="#3F51B5"android:gravity="center"android:padding="10dp"tools:context="com.example.graphicverificationcode.MainActivity"><TextViewandroid:id="@+id/tv_code"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_marginRight="10dp"android:textColor="#ffffff"android:textSize="16sp"/><ImageViewandroid:id="@+id/iv_code"android:layout_width="100dp"android:layout_height="35dp"android:background="#666666"/></LinearLayout>