一种基于自定义控件的验证码

主要是利用自定义View，随机划线画点，不再赘述，上码

<?xml version="1.0" encoding="utf-8"?><RelativeLayout    xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    xmlns:custom="http://schemas.android.com/apk/res-auto"    android:layout_width="match_parent"    android:layout_height="match_parent"    tools:context=".MainActivity">    <RelativeLayout        android:layout_width="match_parent"        android:layout_height="400dp"        android:id="@+id/custom">        <com.mrpeng.customviewdemo.CustomTitleView            android:id="@+id/customview"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_centerInParent="true"            android:padding="10dp"            custom:titleText_customview="3712"            custom:titleTextSize_custome="30sp"            custom:titleTextColor_customview="#ff0000"/>    </RelativeLayout><LinearLayout    android:layout_alignBottom="@id/custom"    android:layout_width="match_parent"    android:layout_height="wrap_content"    android:padding="10dp"    android:orientation="horizontal">    <Button        android:layout_weight="1"        android:id="@+id/btn_change"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="看不清，换"/>    <EditText        android:id="@+id/et_num"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_weight="1"        android:layout_marginLeft="20dp"        android:hint="请输入数字"/>    <Button        android:id="@+id/btn_commit"        android:layout_weight="1"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="提交"/></LinearLayout></RelativeLayout>

mainActivity展示

public class MainActivity extends AppCompatActivity implements View.OnClickListener{    private Button mBtn_change;    private CustomTitleView mCustomview;    @Override    protected void onCreate(Bundle savedInstanceState)    {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        mBtn_change = (Button)findViewById(R.id.btn_change);        mBtn_change.setOnClickListener(this);        Button btn_commit = (Button)findViewById(R.id.btn_commit);        btn_commit.setOnClickListener(this);        mCustomview = (CustomTitleView)findViewById(R.id.customview);    }    @Override    public void onClick(View v)    {        switch(v.getId()){            case R.id.btn_change:                changeCustomView();                break;            case R.id.btn_commit:                break;        }    }    private void changeCustomView()    {        String randomText = mCustomview.randomText();        mCustomview.setTitle(randomText);        mCustomview.invalidate();    }}

重点是这里的自定义View

public class CustomTitleView extends View  implements ChangeView{    public void setTitle(String title)    {        mTitle = title;    }    private String mTitle;    private int mTitleTextColor;    private int mTitleTestSize;    private Paint mPaint;    private Rect mBound;    /**     * 第一个构造 java代码创建视图的时候被调用，如果是从xml填充的视图，就不会调用这个     * 第二个构造 在xml创建时调用     * 第三个构造，不知道     * @param context     */    public CustomTitleView(Context context)    {        super(context);    }    public CustomTitleView(Context context, AttributeSet attrs)    {        super(context, attrs);        TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.CustomTitleView);//        TypedArray typedArray = context.getTheme().obtainStyledAttributes(attrs, R.styleable.CustomTitleView, null, 0);        int n = typedArray.getIndexCount();        for(int i=0;i<n;i++){            int attr = typedArray.getIndex(i);            switch(attr){                case R.styleable.CustomTitleView_titleText_customview:                    mTitle = typedArray.getString(attr);                    break;                case R.styleable.CustomTitleView_titleTextColor_customview:                    mTitleTextColor = typedArray.getColor(attr, Color.BLACK);                    break;                case R.styleable.CustomTitleView_titleTextSize_custome:                    // 默认设置为16sp，TypeValue也可以把sp转化为px                    mTitleTestSize = typedArray.getDimensionPixelSize(attr,                            (int)TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, 16, getResources().getDisplayMetrics()                            ));                    break;            }        }        typedArray.recycle();        mPaint = new Paint();        mPaint.setTextSize(mTitleTestSize);        mBound = new Rect();        mPaint.getTextBounds(mTitle, 0, mTitle.length(), mBound);        this.setOnClickListener(new OnClickListener()        {            @Override            public void onClick(View v)            {                mTitle = randomText();                postInvalidate();            }        });    }    public  String randomText()    {        StringBuffer sb = new StringBuffer();        for(int j=0;j<4;j++){            Random random1 = new Random();            int h = random1.nextInt(10);            sb.append(""+h);        }        return sb.toString();    }    @Override    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)    {        /**         * EXACTLY：一般是设置了明确的值或者是MATCH_PARENT         * AT_MOST：表示子布局限制在一个最大值内，一般为WARP_CONTENT         * UNSPECIFIED：表示子布局想要多大就多大，很少使用         */        int wideMode = MeasureSpec.getMode(widthMeasureSpec);        int heightMode = MeasureSpec.getMode(heightMeasureSpec);        int widthSize = MeasureSpec.getSize(widthMeasureSpec);        int heightSize = MeasureSpec.getSize(heightMeasureSpec);        int width;        int height;        if(wideMode==MeasureSpec.EXACTLY){//已经设置明确值，或者match_parent            width=widthSize;        }else {            mPaint.setTextSize(mTitleTestSize);            mPaint.getTextBounds(mTitle, 0, mTitle.length(), mBound);            float textWidth = mBound.width();            int desired = (int) (getPaddingLeft() + textWidth + getPaddingRight());            width = desired;        }        if (heightMode == MeasureSpec.EXACTLY)        {            height = heightSize;        } else        {            mPaint.setTextSize(mTitleTestSize);            mPaint.getTextBounds(mTitle, 0, mTitle.length(), mBound);            float textHeight = mBound.height();            int desired = (int) (getPaddingTop()+ textHeight + getPaddingBottom() );            height = desired;        }        /**         * 重要方法，onMeasure调用         */        setMeasuredDimension(width,height);    }    @Override    protected void onDraw(Canvas canvas)    {        mPaint.setColor(Color.YELLOW);        canvas.drawRect(0, 0, getMeasuredWidth(), getMeasuredHeight(), mPaint);        mPaint.setColor(mTitleTextColor);//        canvas.drawText(mTitle,getWidth()/2-mBound.width()/2,getHeight()/2+mBound.height()/2,mPaint);        int start=getWidth()/2-mBound.width()/2;        /**         * 数字随机摆放         */        for(int i=0;i<4;i++){            canvas.drawText(mTitle.substring(i,i+1),start,CheckUtil.getTextPosition(getMeasuredHeight()),mPaint);            start+=mBound.width()/5;        }        /**         * 画随机位置的线         */        mPaint.setStrokeWidth(3);        for(int i=0;i<8;i++){            int[] line = CheckUtil.getLine(getMeasuredWidth(), getMeasuredHeight());            canvas.drawLine(line[0],line[1], line[2], line[3],mPaint);//            float top = (float)(Math.random()*getMeasuredHeight());//            float bottom = top+1;//            float left = (float)(0.1*getMeasuredWidth());//            float right = (float)(0.9*getMeasuredWidth());//            canvas.drawRect(left,top,right,bottom,mPaint);        }        /**         * 画点         */        for(int i=0;i<80;i++){            canvas.drawCircle(CheckUtil.getPosition(getMeasuredWidth()),CheckUtil.getPosition(getMeasuredHeight()),1,mPaint);        }    }    @Override    public void updateView()    {        mTitle = randomText();        postInvalidate();    }}

<?xml version="1.0" encoding="utf-8"?><resources>    <attr name="titleText_customview" format="string"/>    <attr name="titleTextColor_customview" format="color"/>    <attr name="titleTextSize_custome" format="dimension"/>    <declare-styleable name="CustomTitleView">        <attr name="titleText_customview"/>        <attr name="titleTextColor_customview"/>        <attr name="titleTextSize_custome"/>    </declare-styleable></resources>用于产生随机点和线的工具类

public class CheckUtil
{
public static int[] getLine(int width, int height){
int [] lineCoordinate=new int[4];
for(int i=0;i<4;i+=2){
lineCoordinate[i]= (int)(Math.random()*width);
lineCoordinate[i+1]= (int)(Math.random()*height);
}
return lineCoordinate;
}

public static int getTextPosition(int height){    int tempPosition = (int)( Math.random()*height );    if(tempPosition<0.5*height ){        tempPosition+=0.5*height;    }    return tempPosition ;}public static int getPosition(int height){    int tempPosition = (int)( Math.random()*height );    if(tempPosition<1){        tempPosition+=1;    }    return tempPosition;}

}

源码