Android仿支付宝支付密码输入框

本文实例为大家分享了Android实现一个仿支付宝支付密码的输入框，主要实现如下：

PasswordView.java

package com.jackie.alipay.password;

import android.annotation.TargetApi;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.os.Build;
import android.util.AttributeSet;
import android.widget.EditText;
import android.widget.Toast;

/**
* Created by Administrator on 2016/10/31.
*/

public class PasswordView extends EditText {
private Paint mBorderPaint; //外框画笔
private Paint mLinePaint; //线的画笔
private Paint mPasswordPaint; //密码画笔
private int mPasswordTextLength; //输入密码的长度
private int mWidth;
private int mHeight;

private static final int PASSWORD_LENGTH = 6;//密码的长度
private static final int PASSWORD_RADIUS = 15;

public PasswordView(Context context) {
this(context, null);
}

public PasswordView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}

public PasswordView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);

initView();
}

private void initView() {
setFocusable(true);

mBorderPaint = new Paint();
mBorderPaint.setStrokeWidth(8);
mBorderPaint.setColor(Color.WHITE);
mBorderPaint.setStyle(Paint.Style.FILL);

mLinePaint = new Paint();
mLinePaint.setColor(Color.parseColor("#838B8B"));
mLinePaint.setStrokeWidth(4);

mPasswordPaint = new Paint();
mPasswordPaint.setColor(Color.BLACK);
mPasswordPaint.setStrokeWidth(12);
}

@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);

mWidth = getMeasuredWidth();
mHeight = getMeasuredHeight();

drawRoundRect(canvas);
drawLine(canvas);
drawPassword(canvas);
}

/**
* 绘制圆角矩形背景
* @param canvas
*/
@TargetApi(Build.VERSION_CODES.LOLLIPOP)
private void drawRoundRect(Canvas canvas) {
canvas.drawRoundRect(0, 0, mWidth, mHeight, 12, 12, mBorderPaint);

}

/**
* 绘制分割线
* @param canvas
*/
private void drawLine(Canvas canvas) {
for (int i = 1; i < PASSWORD_LENGTH; i++) {
 float x = mWidth * i / PASSWORD_LENGTH;
 canvas.drawLine(x, 12, x, mHeight - 12, mLinePaint);
}
}

/**
* 绘制密码
* @param canvas
*/
private void drawPassword(Canvas canvas) {
float cx, cy = mHeight / 2;
float half = mWidth / PASSWORD_LENGTH / 2;
for (int i = 0; i < mPasswordTextLength; i++) {
 cx = mWidth * i / PASSWORD_LENGTH + half;
 canvas.drawCircle(cx, cy, PASSWORD_RADIUS, mPasswordPaint);
}
}

@Override
protected void onTextChanged(CharSequence text, int start, int lengthBefore, int lengthAfter) {
super.onTextChanged(text, start, lengthBefore, lengthAfter);

mPasswordTextLength = text.toString().length();

if (mPasswordTextLength == PASSWORD_LENGTH) {
 Toast.makeText(getContext(), "您设置的密码为: " + text, Toast.LENGTH_SHORT).show();;
}

invalidate();
}

public void reset(){
setText("");
invalidate();
}
}

  效果图如下：

更多内容请参考专题：Android密码使用教程