转载自: https://www.jianshu.com/p/d99e299a44ea
/**
* 设置银行卡输入时每隔4位多一位空格
* @param cardEt
*/
public static void bankCardInput(final EditText cardEt) {
//设置输入长度不超过24位(包含空格)
cardEt.setFilters(new InputFilter[]{
new InputFilter.LengthFilter(24)});
cardEt.addTextChangedListener(new TextWatcher() {
char kongge = ' ';
//改变之前text长度
int beforeTextLength = 0;
//改变之前的文字
private CharSequence beforeChar;
//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;
@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 <= 3
|| isChanged) {
isChanged = false;
return;
}
isChanged = true;
}
@Override
public void afterTextChanged(Editable s) {
if (isChanged) {
location = cardEt.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 == 4 || index == 9 || index == 14 || index == 19)) {
buffer.insert(index, kongge);
konggeNumberC++;
}
index++;
}
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;
}
cardEt.setText(str);
Editable etable = cardEt.getText();
Selection.setSelection(etable, location);
isChanged = false;
}
}
});
}