安卓银行卡输入框实现自动加空格

安卓银行卡输入框实现自动加空格

最近涉及到一个需求，就是添加银行卡，需要在输入卡号的时候，自动每隔四位加一个空格，如下图

布局很简单：

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

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="48dp"
        android:background="@android:color/white"
        android:orientation="horizontal">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:gravity="center_vertical"
            android:paddingLeft="15dp"
            android:text="卡号："
            android:textColor="#333333"
            android:textSize="14sp" />

        <EditText
            android:id="@+id/et_cardNumber"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:background="@null"
            android:gravity="center_vertical"
            android:inputType="number"
            android:maxLines="1"
            android:paddingLeft="15dp"
            android:textColor="#333333"
            android:textSize="14sp" />
    </LinearLayout>

</LinearLayout>

 

java代码

package com.demo.test.demo;

import android.app.Activity;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.widget.EditText;

public class MainActivity extends Activity {
    private EditText et_cardNumber;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        et_cardNumber = (EditText) findViewById(R.id.et_cardNumber);
        et_cardNumber.addTextChangedListener(watcher);
    }

    private TextWatcher watcher = new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {

        }

        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {

        }

        @Override
        public void afterTextChanged(Editable s) {
            String str = s.toString().trim().replace(" ", "");
            String result = "";
            if (str.length() >= 4) {
                et_cardNumber.removeTextChangedListener(watcher);
                for (int i = 0; i < str.length(); i++) {
                    result += str.charAt(i);
                    if ((i + 1) % 4 == 0) {
                        result += " ";
                    }
                }
                if (result.endsWith(" ")) {
                    result = result.substring(0, result.length() - 1);
                }
                et_cardNumber.setText(result);
                et_cardNumber.addTextChangedListener(watcher);
                et_cardNumber.setSelection(et_cardNumber.getText().toString().length());//焦点到输入框最后位置
            }
        }
    };

}

小弟第一次写博客，大神勿喷哈，希望能帮到需要的人