android 自定义View生成验证码

//自定义view 生成验证码

package com.yh.indentfyingcode.views;

import java.util.Random;


import com.example.indentfyingcode.R;


import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.util.Log;
import android.util.TypedValue;
import android.view.View;
/**自定义view 生成验证码
 * @author yh
 * 2016.2.24
 * */
public class IndentfyingCode extends View {
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' };
/**验证码*/
private String text;
private int textColor;
private int textSize;
private Rect rect;
private Paint mPaint;
private Random random;
private int textCodeWid;
private int textCodeHei;
private Context context;
/**默认噪线条数*/
private int lines=3;
/**验证码长度*/
private int textLength=5;
public IndentfyingCode(Context context) {
this(context, null);
// TODO Auto-generated constructor stub
this.context=context;
}


public IndentfyingCode(Context context, AttributeSet attrs) {
this(context, attrs, 0);
// TODO Auto-generated constructor stub
this.context=context;
}


public IndentfyingCode(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
// TODO Auto-generated constructor stub
this.context=context;
random = new Random();
TypedArray a = context.getTheme().obtainStyledAttributes(attrs,
R.styleable.IndentfyingCode, defStyle, 0);
for (int i = 0; i < a.getIndexCount(); i++) {
switch (a.getIndex(i)) {
case R.styleable.IndentfyingCode_titleText:
// text = a.getString(a.getIndex(i));
text = text(textLength);
break;


case R.styleable.IndentfyingCode_titleTextColor:
textColor = a.getColor(a.getIndex(i), Color.BLACK);
break;
case R.styleable.IndentfyingCode_titleTextSize:
textSize = a.getDimensionPixelSize(a.getIndex(i),
(int) TypedValue.applyDimension(
TypedValue.COMPLEX_UNIT_SP, 14, getResources()
.getDisplayMetrics()));
break;
}
}


a.recycle();
mPaint = new Paint();
mPaint.setTextSize(textSize);
mPaint.setColor(textColor);
rect = new Rect();

mPaint.getTextBounds(text, 0, text.length(), rect);
textCodeWid=rect.width();
textCodeHei=rect.height();

this.setOnClickListener(new OnClickListener() {


@Override
public void onClick(View v) {
// TODO Auto-generated method stub
text = text(textLength);
postInvalidate();
}
});
}


private String text(int n) {
StringBuffer sb = new StringBuffer();
for (int i = 0; i < n; i++) {
sb.append(CHARS[random.nextInt(CHARS.length)]);
}
String s = sb.toString();
sb = null;
return s;
}


@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// TODO Auto-generated method stub
super.onMeasure(widthMeasureSpec, heightMeasureSpec);


;
setMeasuredDimension(
setsize(widthMeasureSpec, rect.width(), getPaddingLeft(),
getPaddingRight()),
setsize(heightMeasureSpec, rect.height(), getPaddingTop(),
getPaddingBottom()));
}


private int setsize(int widthMeasureSpec, int rectsize, int pading1,
int pading2) {
int measureMode = MeasureSpec.getMode(widthMeasureSpec);
int measureSize = MeasureSpec.getSize(widthMeasureSpec);
switch (measureMode) {
case MeasureSpec.EXACTLY:


break;


case MeasureSpec.AT_MOST:
measureSize = Math.min(measureSize, rectsize);
break;
}
return measureSize + pading1 + pading2;
}


@Override
protected void onDraw(Canvas canvas) {
// TODO Auto-generated method stub
super.onDraw(canvas);
mPaint.setColor(Color.WHITE);

canvas.drawRect(0, 0, getMeasuredWidth(), getMeasuredHeight(), mPaint);
mPaint.setColor(textColor);
for (int i = 0; i < text.length(); i++) {
String s=text.substring(i, i+1);


int textWid=px2dip( context, textSize);

mPaint.setColor(Color.rgb(random.nextInt(256), random.nextInt(256), random.nextInt(256)));
canvas.drawText(s,getWidth() / 2 - textCodeWid / 2+i*textWid, getHeight()
/ 2 + textCodeHei/ 2, mPaint);
}
for (int i = 0; i <lines; i++) {
mPaint.setColor(Color.rgb(random.nextInt(256), random.nextInt(256), random.nextInt(256)));
int x1=random.nextInt(getWidth());
int x2=random.nextInt(getWidth());
int y1=random.nextInt(getHeight());
int y2=random.nextInt(getHeight());
canvas.drawLine(x1, x2, y1, y2, mPaint);
}
}
/** 像素转dip */
public static int px2dip(Context context, float pxValue) {
final float scale = context.getResources().getDisplayMetrics().density;
return (int) (pxValue / scale + 0.5f) ;
}

}

//自定义属性

<?xml version="1.0" encoding="utf-8"?>
<resources>


    <!-- string,color,demension,integer,enum,reference,float,boolean,fraction,flag -->
    <attr name="titleText" format="string" />
    <attr name="titleTextColor" format="color" />
    <attr name="titleTextSize" format="dimension" />


    <declare-styleable name="IndentfyingCode">
        <attr name="titleText" />
        <attr name="titleTextColor" />
        <attr name="titleTextSize" />
    </declare-styleable>


</resources>

// 在activity中测试

package com.yh.indentfyingcode;


import com.example.indentfyingcode.R;


import android.app.Activity;
import android.os.Bundle;
/**
 * @author yh
 * 2016.2.24
 * */
public class IndentfyingCodeActivity extends Activity{
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.indentfyingcodelayout);
}
}

//布局文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:y="http://schemas.android.com/apk/res/com.example.indentfyingcode"
 
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#383838"
    
    android:orientation="vertical" >
<View android:layout_width="wrap_content"
    android:layout_height="0dp"
    android:layout_weight="1"/>
    <com.yh.indentfyingcode.views.IndentfyingCode
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
       android:padding="10dp"
        y:titleText="3546d"
        y:titleTextColor="#FF0000"
        y:titleTextSize="30sp" />
    <View android:layout_width="wrap_content"
    android:layout_height="0dp"
    android:layout_weight="1"/>


</LinearLayout>