先给大家展示下效果图，如果大家感觉还不错，请参考实现代码

很简单的一个例子,点击刷新验证码,刷新当前显示的验证码,点击确定,如果输入的和显示的匹配,就会跳转到下一个界面中,这里只是实现了跳转,并没有进行其它的操作

好了 接下来就是代码了

首先看MainActivity的布局

<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" >
<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginLeft="20dp"
android:layout_marginTop="77dp"
android:text="验证码:" />
<EditText
android:id="@+id/vc_code"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBaseline="@+id/textView1"
android:layout_alignBottom="@+id/textView1"
android:layout_toRightOf="@+id/textView1"
android:ems="10" >
<requestFocus />
</EditText>
<Button
android:id="@+id/vc_ok"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/vc_image"
android:layout_alignRight="@+id/vc_shuaixi"
android:layout_below="@+id/vc_shuaixi"
android:layout_marginTop="15dp"
android:text="确定" />
<Button
android:id="@+id/vc_shuaixi"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignRight="@+id/vc_code"
android:layout_alignTop="@+id/vc_image"
android:layout_marginRight="20dp"
android:text="刷新验证码" />
<ImageView
android:id="@+id/vc_image"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/textView1"
android:layout_below="@+id/vc_code"
android:layout_marginTop="25dp"
android:src="@drawable/ic_launcher" />
</RelativeLayout>

MainActivity代码

package com.example.yanzhengma;
import android.R.string;
import android.os.Bundle;
import android.app.Activity;
import android.content.ClipData.Item;
import android.content.Intent;
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.TextView;
import android.widget.Toast;
public class MainActivity extends Activity implements OnClickListener {
ImageView vc_image; // 图片
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(Code.getInstance().getBitmap());
vc_code = (EditText) findViewById(R.id.vc_code);
getCode = Code.getInstance().getCode(); // 获取显示的验证码
vc_shuaixi = (Button) findViewById(R.id.vc_shuaixi);
vc_shuaixi.setOnClickListener(this);
vc_ok = (Button) findViewById(R.id.vc_ok);
vc_ok.setOnClickListener(this);
}
@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;
}
@Override
public void onClick(View view) {
// TODO Auto-generated method stub
switch (view.getId()) {
case R.id.vc_shuaixi:
vc_image.setImageBitmap(Code.getInstance().getBitmap());
getCode = Code.getInstance().getCode();
break;
case R.id.vc_ok:
String v_code = vc_code.getText().toString().trim();
if (v_code == null || v_code.equals("")) {
Toast.makeText(MainActivity.this, "验证码为空", Toast.LENGTH_SHORT).show();
} else if (!v_code.equals(getCode)) {
Toast.makeText(MainActivity.this, "验证码错误", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(MainActivity.this, "验证成功", Toast.LENGTH_SHORT).show();
Intent itIntent = new Intent(MainActivity.this,
secondActivity.class);
startActivity(itIntent);
MainActivity.this.finish();
}
break;
}
}
}

好了,到重点部分了,绘制验证码

package com.example.yanzhengma;
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;
public class Code {
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 Code bpUtil;
private Code() {
};
public static Code getInstance() {
if (bpUtil == null)
bpUtil = new Code();
return bpUtil;
}
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
private int width = DEFAULT_WIDTH;
private int height = DEFAULT_HEIGHT;
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;
private int codeLength = DEFAULT_CODE_LENGTH;
private int line_number = DEFAULT_LINE_NUMBER;
private int font_size = DEFAULT_FONT_SIZE;
private String code;// 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);
c.restore();//
return bp;
}
public String getCode() {
return code;
}
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类型参数，负数表示右斜，整数左斜
}
private void randomPadding() {
padding_left += base_padding_left + random.nextInt(range_padding_left);
padding_top = base_padding_top + random.nextInt(range_padding_top);
}
}

好了 代码都有注释,应该会看的明白的

以上所述是小编给大家介绍的Android 验证码功能实现代码，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对脚本之家网站的支持！