身份证和银行卡输入时根据规则分析

1. 身份证输入过程中，按照6位、8位、4位分割显示，实现如下：

/**
 * author : wyy
 * time   : 2018/06/25
 * desc   : 身份证输入过程中，自动 6，8, 4  格式化显示
 */
public class IdCardTextChangeListener implements TextWatcher {

    //改变之前text长度
    int beforeTextLength = 0;
    //改变之后text长度
    int onTextLength = 0;
    //是否改变空格或光标
    boolean isChanged = false;
    // 记录光标的位置
    int location = 0;
    private char[] tempChar;
    private StringBuffer buffer = new StringBuffer();
    //已有空格数量
    int konggeNumberB = 0;
    private ClearableEditText IdcardEt;

    private static final char kongge = ' ';

    public IdCardTextChangeListener(ClearableEditText IdcardEt) {
        this.IdcardEt = IdcardEt;
    }

    @Override
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {
        beforeTextLength = s.length();
        if (buffer.length() > 0) {
            buffer.delete(0, buffer.length());
        }
        konggeNumberB = 0;
        for (int i = 0; i < s.length(); i++) {
            if (s.charAt(i) == ' ') {
                konggeNumberB++;
            }
        }
    }

    @Override
    public void onTextChanged(CharSequence s, int start, int before, int count) {
        onTextLength = s.length();
        buffer.append(s.toString());
        if (onTextLength == beforeTextLength || onTextLength <= 6 || isChanged) {
            isChanged = false;
            return;
        }
        isChanged = true;
    }

    @Override
    public void afterTextChanged(Editable s) {
        if (isChanged) {
            location = IdcardEt.getSelectionEnd();
            int index = 0;
            while (index < buffer.length()) {
                if (buffer.charAt(index) == kongge) {
                    buffer.deleteCharAt(index);
                } else {
                    index++;
                }
            }
            index = 0;
            int konggeNumberC = 0;
            while (index < buffer.length()) {
                if ((index == 6 || index == 15)) {
                    buffer.insert(index, kongge);
                    konggeNumberC++;
                }
                index++;
            }

            ///输入后字符串空格比之前的要多的时候
            if (konggeNumberC > konggeNumberB) {
                location += (konggeNumberC - konggeNumberB);
            }

            tempChar = new char[buffer.length()];
            buffer.getChars(0, buffer.length(), tempChar, 0);
            String str = buffer.toString();
            if (location > str.length()) {
                location = str.length();
            } else if (location < 0) {
                location = 0;
            }

            IdcardEt.setText(str);
            Editable etable = IdcardEt.getText();
            Selection.setSelection(etable, location);
            isChanged = false;
        }
    }
}

2 . 银行卡输入过程中，每四位分割显示

这里写代码片