（五十一）生成图片验证码的代码如下所示
1、程序的结构如下所示：
2、LoginImageViewCode.java的代码如下所示
package com.app.code; import java.util.Random; import android.content.Context; import android.graphics.Bitmap; import android.graphics.Bitmap.Config; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; public class LoginImageViewCode { private static Context context; 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 LoginImageViewCode bpUtil; private LoginImageViewCode(Context context) { this.context = context; }; public static LoginImageViewCode getInstance(Context context) { if (bpUtil == null) bpUtil = new LoginImageViewCode(context); 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 = 4;// 多少条干扰线 private static final int BASE_PADDING_LEFT = 20; // 左边距 private static final int RANGE_PADDING_LEFT = 15;// 左边距范围值 private static final int BASE_PADDING_TOP = 42;// 上边距 private static final int RANGE_PADDING_TOP = 28;// 上边距范围值 private static final int DEFAULT_WIDTH = 210;// 默认宽度.图片的总宽 private static final int DEFAULT_HEIGHT = 92;// 默认高度.图片的总高 private static final int DEFAULT_POINT_NUMBER = 20; private final int DEFAULT_COLOR = 0xff;// 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 point_number = DEFAULT_POINT_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; // 产生一个相同大小的画布 Bitmap bp = Bitmap.createBitmap(width, height, Config.ARGB_8888); Canvas c = new Canvas(bp); code = createCode(); Paint paint = new Paint(); for (int i = 0; i < code.length(); i++) { paint.setTextSize(font_size); randomTextStyle(paint); randomPadding(); c.drawText(code.charAt(i) + "", padding_left, padding_top, paint);// 以（padding_left,padding_top）为原点，使用画笔绘制文本code.charAt(i) // // // + // "" } int redColor = context.getResources().getColor( R.color.login_promt_text_red); // 设置线条的颜色为红色 for (int i = 0; i < line_number; i++) { drawLine(c, paint, redColor); } for (int i = 0; i < point_number; i++) { drawPoint(c, paint); } c.save(Canvas.ALL_SAVE_FLAG);// 保存 c.restore();// return bp; } public String getCode() { return code.toLowerCase(); } 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 drawPoint(Canvas canvas, Paint paint) { int color = context.getResources().getColor(R.color.login_text_gray); // 设置字体的颜色为红色 int x = random.nextInt(width); int y = random.nextInt(height); paint.setStrokeWidth(3); paint.setColor(color); canvas.drawPoint(x, y, paint); } private void drawLine(Canvas canvas, Paint paint, int color) { // int color = randomColor(); int startX = random.nextInt(width); int startY = random.nextInt(height); int stopX = random.nextInt(width); int stopY = random.nextInt(height); // int startX = (Math.abs(random.nextInt(width)))%(width+1)+width; // int startY = (Math.abs(random.nextInt(height)))%(height+1)+height; // int startX = 0; // int startY = random.nextInt(height); // int stopX = (Math.abs(random.nextInt(width)))%(width+1)+width; // int stopY = (Math.abs(random.nextInt(height)))%(height+1)+height; paint.setStrokeWidth(3); 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(); int color = context.getResources().getColor( R.color.login_promt_text_red); // 设置字体的颜色为红色 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); } }
2、MainActivity.java的代码如下所示
package com.app.code; import android.os.Bundle; import android.app.Activity; import android.util.Log; import android.view.Menu; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.EditText; import android.widget.ImageView; import android.widget.Toast; public class MainActivity extends Activity { ImageView vc_image; Button vc_shuaixi,vc_ok; String getCode=null; EditText vc_code; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); vc_image=(ImageView)findViewById(R.id.vc_image); vc_image.setImageBitmap(LoginImageViewCode.getInstance(MainActivity.this).getBitmap()); vc_code=(EditText) findViewById(R.id.vc_code); getCode=LoginImageViewCode.getInstance(MainActivity.this).getCode(); //获取显示的验证码 Log.e("info", getCode+"----"); vc_shuaixi=(Button)findViewById(R.id.vc_shuaixi); vc_shuaixi.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub vc_image.setImageBitmap(LoginImageViewCode.getInstance(MainActivity.this).getBitmap()); getCode=LoginImageViewCode.getInstance(MainActivity.this).getCode(); } }); vc_ok=(Button)findViewById(R.id.vc_ok); vc_ok.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub String v_code=vc_code.getText().toString().trim(); if(v_code==null||v_code.equals("")){ Toast.makeText(MainActivity.this, "没有填写验证码", 2).show(); }else if(!v_code.equals(getCode)){ Toast.makeText(MainActivity.this, "验证码填写不正确", 2).show(); }else{ Toast.makeText(MainActivity.this, "操作成功", 2).show(); } } }); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.main, menu); return true; } }
3、activity_main.xml的代码如下所示
<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=".MainActivity" > <LinearLayout android:id="@+id/yh" android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="horizontal" > <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="用户名:" /> <EditText android:layout_width="fill_parent" android:layout_height="wrap_content" /> </LinearLayout> <LinearLayout android:id="@+id/pwd" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_below="@id/yh" android:orientation="horizontal" > <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="密码:" /> <EditText android:layout_width="fill_parent" android:layout_height="wrap_content" /> </LinearLayout> <LinearLayout android:id="@+id/code" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_below="@id/pwd" android:layout_marginTop="4dp" android:gravity="center_vertical" android:orientation="horizontal" > <LinearLayout android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginBottom="10dp" android:layout_marginLeft="10dp" android:layout_marginRight="10dp" android:layout_marginTop="5dp" android:orientation="horizontal" > <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginLeft="20dp" android:layout_marginRight="5dp" android:text="验 证 码:" android:textColor="#000000" /> <EditText android:id="@+id/vc_code" android:layout_width="60dp" android:layout_height="wrap_content" android:layout_weight="1" android:background="#0000" android:maxLength="4" android:paddingBottom="10dp" android:paddingLeft="10dp" android:paddingTop="10dp" android:textColor="#000000" android:textSize="14sp" /> </LinearLayout> <ImageView android:id="@+id/vc_image" android:layout_width="600dp" android:layout_height="600dp" android:layout_marginBottom="10dp" android:layout_marginTop="5dp" android:layout_weight="1" /> <Button android:id="@+id/vc_shuaixi" android:layout_width="40dp" android:layout_height="wrap_content" android:layout_gravity="center_vertical" android:layout_marginBottom="10dp" android:layout_marginLeft="5dp" android:layout_marginRight="5dp" android:layout_marginTop="5dp" android:background="@android:color/transparent" android:text="刷新验证码" android:textColor="#7f7f7f" android:textSize="12sp" android:textStyle="italic" /> </LinearLayout> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_below="@id/code" android:orientation="horizontal" > <Button android:id="@+id/vc_ok" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="确定" /> </LinearLayout> </RelativeLayout>
4、color.xml的代码如下所示
<?xml version="1.0" encoding="utf-8"?> <resources> <color name="login_promt_text_red">#eb271c</color> <color name="login_text_gray">#a8a8a8</color> </resources>