Android 登陆页面 图片验证码
话不多说，先上图片：
其中包括了验证码和账号密码验证简单的登陆界面。要想实现这个功能，博主可是花费了一番功夫，今天把经验分享出来，跟大家分享，第一次写博客，后面我也会把我近期Android的一些项目贴出来，供大家踩坑。
CodeUtils
package com.example.myapplication;
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 HuGuanzZhong.
* 用于图片验证码的工具类
*/
public class CodeUtils {
// 定义所显示的数据类型
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'
};
// 绘图准备
private static CodeUtils mCodeUtils;
private int mPaddingLeft, mPaddingTop;
private StringBuilder mBuilder = new StringBuilder();
private Random mRandom = new Random();
private static final int DEFAULT_CODE_LENGTH = 6;//验证码的长度 这里6位，可以简单点，简单一点
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;
}
public Bitmap createBitmap() {
mPaddingLeft = 0;
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);
}
for (int i = 0; i < DEFAULT_LINE_NUMBER; i++) {
drawLine(canvas, paint);
}
// 这段代码，由于API28版本太高不能使用，所以需要降版本，否则报错
canvas.save(Canvas.ALL_SAVE_FLAG);
canvas.restore();
return bitmap;
}
public String getCode() {
return code;
}
public String createCode() {
mBuilder.delete(0, mBuilder.length());
for (int i = 0; i < DEFAULT_CODE_LENGTH; i++) {
mBuilder.append(CHARS[mRandom.nextInt(CHARS.length)]);
}
return mBuilder.toString();
}
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);
}
private int randomColor() {
mBuilder.delete(0, mBuilder.length());
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());
}
private void randomTextStyle(Paint paint) {
int color = randomColor();
paint.setColor(color);
paint.setFakeBoldText(mRandom.nextBoolean());
float skewX = mRandom.nextInt(11) / 10;
skewX = mRandom.nextBoolean() ? skewX : -skewX;
paint.setTextSkewX(skewX);
}
private void randomPadding() {
mPaddingLeft += BASE_PADDING_LEFT + mRandom.nextInt(RANGE_PADDING_LEFT);
mPaddingTop = BASE_PADDING_TOP + mRandom.nextInt(RANGE_PADDING_TOP);
}
}这是一个工具类，可以使用我的或者使用其他人的，网上一抓一大把，工具类的使用会有问题，我在做的时候是安卓8.0，由于API是28.会报类型错误。具体错误地点，已经标注出来了。这里一定要注意降级！降级！降级！
API降级方法：
非gradle:File->Project Structure ->选择你所选择的Modules
gradle：修改SdkVersion ，后面牵扯包的引用，具体详情看其他博主详细讲了，我们hai
附上我的build代码
apply plugin: 'com.android.application'
android {
compileSdkVersion 25
buildToolsVersion '27.0.3'
defaultConfig {
applicationId "example.com.sunshine"
minSdkVersion 16
targetSdkVersion 25
versionCode 1
versionName "1.0"
testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
repositories {
jcenter()
}
}
dependencies {
implementation 'com.android.support.constraint:constraint-layout:1.0.2'
compile fileTree(include: ['*.jar'], dir: 'libs')
testImplementation 'junit:junit:4.12'
androidTestImplementation 'com.android.support.test:runner:1.0.2'
androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
exclude group: 'com.android.support', module: 'support-annotations'
})
compile 'com.android.support:support-v4:25.3.1'
compile 'com.android.support:support-v13:25.3.1'
compile 'com.android.support:cardview-v7:25.3.1'
compile 'com.android.support:appcompat-v7:25.3.1'
implementation files('libs/okhttp-3.2.0.jar')
implementation files('libs/okio-1.12.0.jar')
}
img_yzm.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
// 调用工具类
codeUtils = CodeUtils.getInstance();
// 生成bitmap
Bitmap bitmap = codeUtils.createBitmap();
// 设置进imageView
img_yzm.setImageBitmap(bitmap);
String code = codeUtils.getCode().toLowerCase();
System.out.println("code------------:" + code);
}
});最好把code打印出来，毕竟有时候并不一定能看得清。测试使用。
最后贴出整个项目源码：
MainAcitvity:登陆首页
package com.example.myapplication;
import android.content.Intent;
import android.graphics.Bitmap;
import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
private ImageView img_yzm;
private EditText ed_uname, ed_pwd, ed_yzm;
private CodeUtils codeUtils;
private Button btn_login, btn_cz;
private String codeStr, uname, upwd;
private String name, pwd;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initView();
initData();
}
private void initView() {
img_yzm = (ImageView) findViewById(R.id.img_yzm);
ed_uname = (EditText) findViewById(R.id.ed_uname);
ed_pwd = (EditText) findViewById(R.id.ed_pwd);
ed_yzm = (EditText) findViewById(R.id.ed_yzm);
btn_login = (Button) findViewById(R.id.btn_login);
btn_cz = (Button) findViewById(R.id.btn_cz);
}
private void initData() {
// 设置验证码，验证码项目需要SDK降级
codeUtils = CodeUtils.getInstance();
Bitmap bitmap = codeUtils.createBitmap();
img_yzm.setImageBitmap(bitmap);
img_yzm.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
codeUtils = CodeUtils.getInstance();
Bitmap bitmap = codeUtils.createBitmap();
img_yzm.setImageBitmap(bitmap);
String code = codeUtils.getCode().toLowerCase();
System.out.println("code------------:" + code);
}
});
// 设置登录按钮
btn_login.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
// 将获取的验证码进行小写判断
codeStr = ed_yzm.getText().toString().trim().toLowerCase();
uname = ed_uname.getText().toString().trim();
upwd = ed_pwd.getText().toString().trim();
String code = codeUtils.getCode().toLowerCase();
// 进行验证码判断
if (null == codeStr || TextUtils.isEmpty(codeStr)||!code.equalsIgnoreCase(codeStr)) {
Toast.makeText(MainActivity.this, "请输入正确验证码", Toast.LENGTH_SHORT).show();
}
// 将验证码变成小写字母
System.out.println("code------------:" + code);
if (code.equalsIgnoreCase(codeStr)) {
if (uname.equals(name) && upwd.equals(pwd)) {
Toast.makeText(MainActivity.this, "成功登陆", Toast.LENGTH_SHORT).show();
Intent intent = new Intent();
intent.putExtra("uname", uname);
intent.setClass(MainActivity.this, FirstActivity.class);
startActivity(intent);
} else {
Toast.makeText(MainActivity.this, "请输入正确的账号密码", Toast.LENGTH_SHORT).show();
}
}
}
});
btn_cz.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
ed_pwd.setText("");
ed_uname.setText("");
ed_yzm.setText("");
}
});
}
}
xml文件