一个字符带下滑线的EditText

效果样式：

这个比较特别的editText是公司的一个新的需求，我也是在网上找了一下，然后看到了一篇博客然后修改成自己需要的样式。这种一般的思路就是在onDraw()方法绘制editText的特别的样式，如果输入里面的值是*这种特殊字符就只用直接绘制,如果需要输入进去的值则可以在onTextChanged方法中获取每一次更改editText值，在onDraw方法里一个个的绘制。

自定义的editText

package com.kkrs.selfedit;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.RectF;
import android.text.InputFilter;
import android.text.TextUtils;
import android.util.AttributeSet;
import android.util.Log;
import android.widget.EditText;

import static android.graphics.Paint.ANTI_ALIAS_FLAG;

/**
 * Created by zd on 2018/11/27.
 */

public class InputView extends EditText {
    private Context mContext;
    /**
     * 第一个圆开始绘制的圆心坐标
     */
    private float startX;
    private float startY;

    private float cX;

    int psdType = 0;

    /**
     * 实心圆的半径
     */
    private int radius = 10;
    /**
     * view的高度
     */
    private int height;
    private int width;

    /**
     * 当前输入密码位数
     */
    private int textLength = 0;
    private int bottomLineLength;
    /**
     * 最大输入位数
     */
    private int maxCount = 6;
    /**
     * 圆的颜色   默认BLACK
     */
    private int circleColor = Color.BLACK;
    /**
     * 底部线的颜色   默认GRAY
     */
    private int bottomLineColor = Color.GRAY;

    /**
     * 分割线开始的坐标x
     */
    private int divideLineWStartX;

    /**
     * 分割线的宽度  默认2
     */
    private int divideLineWidth = 2;
    /**
     * 竖直分割线的颜色
     */
    private int divideLineColor = Color.GRAY;
    private int focusedColor = Color.BLUE;
    private RectF rectF = new RectF();
    private RectF focusedRecF = new RectF();

    private String texts = "";
    /**
     * 矩形边框的圆角
     */
    private int rectAngle = 0;
    /**
     * 圆的画笔
     */
    private Paint circlePaint;
    /**
     * 底部线的画笔
     */
    private Paint bottomLinePaint;

    /**
     * 需要对比的密码  一般为上次输入的
     */
    private String mComparePassword = null;

    /**
     * 当前输入的位置索引
     */
    private int position = 0;

    private onPasswordListener mListener;

    public InputView(Context context, AttributeSet attrs) {
        super(context, attrs);
        mContext = context;

        getAtt(attrs);
        initPaint();

        this.setBackgroundColor(Color.TRANSPARENT);
        this.setCursorVisible(false);
        this.setFilters(new InputFilter[]{new InputFilter.LengthFilter(maxCount)});

    }

    private void getAtt(AttributeSet attrs) {
        TypedArray typedArray = mContext.obtainStyledAttributes(attrs, R.styleable.PayPsdInputView);
        maxCount = typedArray.getInt(R.styleable.PayPsdInputView_maxCount, maxCount);
        circleColor = typedArray.getColor(R.styleable.PayPsdInputView_circleColor, circleColor);
        bottomLineColor = typedArray.getColor(R.styleable.PayPsdInputView_bottomLineColor, bottomLineColor);
        radius = typedArray.getDimensionPixelOffset(R.styleable.PayPsdInputView_radius, radius);
        divideLineWidth = typedArray.getDimensionPixelSize(R.styleable.PayPsdInputView_divideLineWidth, divideLineWidth);
        divideLineColor = typedArray.getColor(R.styleable.PayPsdInputView_divideLineColor, divideLineColor);
        psdType = typedArray.getInt(R.styleable.PayPsdInputView_psdType, psdType);
        rectAngle = typedArray.getDimensionPixelOffset(R.styleable.PayPsdInputView_rectAngle, rectAngle);
        focusedColor = typedArray.getColor(R.styleable.PayPsdInputView_focusedColor, focusedColor);

        typedArray.recycle();
    }

    /**
     * 初始化画笔
     */
    private void initPaint() {

        circlePaint = getPaint(5, Paint.Style.FILL, circleColor);

        bottomLinePaint = getPaint(2, Paint.Style.FILL, bottomLineColor);

    }

    /**
     * 设置画笔
     *
     * @param strokeWidth 画笔宽度
     * @param style       画笔风格
     * @param color       画笔颜色
     * @return
     */
    private Paint getPaint(int strokeWidth, Paint.Style style, int color) {
        Paint paint = new Paint(ANTI_ALIAS_FLAG);
        paint.setStrokeWidth(strokeWidth);
        paint.setStyle(style);
        paint.setColor(color);
        paint.setAntiAlias(true);
        paint.setTextSize(40);
        return paint;
    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        height = h;
        width = w;

        divideLineWStartX = w / maxCount;

        startX = w / maxCount / 2;
        startY = h / 2;

        bottomLineLength = w / (maxCount + 2);

        rectF.set(0, 0, width, height);

    }

    @Override
    protected void onDraw(Canvas canvas) {
        //不删除的画会默认绘制输入的文字
//       super.onDraw(canvas);
        drawBottomBorder(canvas);

        switch (psdType){
            case 0:
                char[] cc;
                cc=texts.toCharArray();
                for (int i = 0; i < cc.length; i++) {
                    Log.e("sys","cc="+cc[i]);
                    canvas.drawText(cc[i]+"",startX + i * 2 * startX,
                            startY,circlePaint);
                }
                break;
            case 1:
                drawPsdCircle(canvas);

                break;
        }
    }

    /**
     * 画密码实心圆
     *
     * @param canvas
     */
    private void drawPsdCircle(Canvas canvas) {
        for (int i = 0; i < textLength; i++) {
            canvas.drawCircle(startX + i * 2 * startX,
                    startY,
                    radius,
                    circlePaint);
        }
    }
    /**
     * 画底部显示的分割线
     *
     * @param canvas
     */
    private void drawBottomBorder(Canvas canvas) {

        for (int i = 0; i < maxCount; i++) {
            cX = startX + i * 2 * startX;
            canvas.drawLine(cX - bottomLineLength / 2,
                    height,
                    cX + bottomLineLength / 2,
                    height, bottomLinePaint);
        }
    }

    @Override
    protected void onTextChanged(CharSequence text, int start, int lengthBefore, int lengthAfter) {
        super.onTextChanged(text, start, lengthBefore, lengthAfter);
        this.position = start + lengthAfter;
        textLength = text.toString().length();
        texts = text.toString();
        Log.e("onTextChanged",text.toString());

        if (textLength == maxCount) {
            if (mListener != null) {
                if (TextUtils.isEmpty(mComparePassword)) {
                    mListener.inputFinished(getPasswordString());
                } else {
                    if (TextUtils.equals(mComparePassword, getPasswordString())) {
                        mListener.onEqual(getPasswordString());
                    } else {
                        mListener.onDifference(mComparePassword, getPasswordString());
                    }
                }
            }
        }

        invalidate();

    }

    @Override
    protected void onSelectionChanged(int selStart, int selEnd) {
        super.onSelectionChanged(selStart, selEnd);

        //保证光标始终在最后
        if (selStart == selEnd) {
            setSelection(getText().length());
        }
    }

    /**
     * 获取输入的密码
     *
     * @return
     */
    public String getPasswordString() {
        return getText().toString().trim();
    }

    public void setComparePassword(String comparePassword, onPasswordListener listener) {
        mComparePassword = comparePassword;
        mListener = listener;
    }

    public void setComparePassword(onPasswordListener listener) {
        mListener = listener;
    }

    public void setComparePassword(String psd) {
        mComparePassword = psd;
    }

    /**
     * 清空密码
     */
    public void cleanPsd() {
        setText("");
    }

    /**
     * 密码比较监听
     */
    public interface onPasswordListener {
        void onDifference(String oldPsd, String newPsd);

        void onEqual(String psd);

        void inputFinished(String inputPsd);
    }
}

在xml的用法：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:psd="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    >

    <com.kkrs.selfedit.InputView
        android:id="@+id/pwd"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="10dp"
        android:layout_marginTop="20dp"
        android:inputType="number"
        psd:maxCount="6"
        psd:psdType="pwd"/>

    <com.kkrs.selfedit.InputView
        android:id="@+id/phone"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="10dp"
        android:layout_marginTop="20dp"
        android:inputType="number"
        psd:maxCount="11"
        psd:psdType="phone"/>

</LinearLayout>

github：https://github.com/tempest1/SelfEdit