我有一个EditText，其中用户应该输入一个包含小数的数字，我想要一个千位分隔符自动添加到输入数字我尝试了几个其他方法但有些不允许浮点数，所以我想出了这个代码有效只是字符串输入没有被实时编辑成可能有千位分隔符的字符串输入，并且错误似乎源于s.replace（）;
am2 = new TextWatcher(){
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
public void onTextChanged(CharSequence s, int start, int before, int count) {}
public void afterTextChanged(Editable s) {
if (s.toString().equals("")) {
amount.setText("");
value = 0;
}else{
StringBuffer strBuff = new StringBuffer();
char c;
for (int i = 0; i < amount2.getText().toString().length() ; i++) {
c = amount2.getText().toString().charAt(i);
if (Character.isDigit(c)) {
strBuff.append(c);
}
}
value = Double.parseDouble(strBuff.toString());
reverse();
NumberFormat nf2 = NumberFormat.getInstance(Locale.ENGLISH);
((DecimalFormat)nf2).applyPattern("###,###.#######");
s.replace(0, s.length(), nf2.format(value));
}
}
};
此类解决了问题，允许十进制输入并添加千位分隔符。
public class NumberTextWatcher implements TextWatcher {
private DecimalFormat df;
private DecimalFormat dfnd;
private boolean hasFractionalPart;
private EditText et;
public NumberTextWatcher(EditText et)
{
df = new DecimalFormat("#,###.##");
df.setDecimalSeparatorAlwaysShown(true);
dfnd = new DecimalFormat("#,###");
this.et = et;
hasFractionalPart = false;
}
@SuppressWarnings("unused")
private static final String TAG = "NumberTextWatcher";
public void afterTextChanged(Editable s)
{
et.removeTextChangedListener(this);
try {
int inilen, endlen;
inilen = et.getText().length();
String v = s.toString().replace(String.valueOf(df.getDecimalFormatSymbols().getGroupingSeparator()), "");
Number n = df.parse(v);
int cp = et.getSelectionStart();
if (hasFractionalPart) {
et.setText(df.format(n));
} else {
et.setText(dfnd.format(n));
}
endlen = et.getText().length();
int sel = (cp + (endlen - inilen));
if (sel > 0 && sel <= et.getText().length()) {
et.setSelection(sel);
} else {
// place cursor at the end?
et.setSelection(et.getText().length() - 1);
}
} catch (NumberFormatException nfe) {
// do nothing?
} catch (ParseException e) {
// do nothing?
}
et.addTextChangedListener(this);
}
public void beforeTextChanged(CharSequence s, int start, int count, int after)
{
}
public void onTextChanged(CharSequence s, int start, int before, int count)
{
if (s.toString().contains(String.valueOf(df.getDecimalFormatSymbols().getDecimalSeparator())))
{
hasFractionalPart = true;
} else {
hasFractionalPart = false;
}
}
}
资料来源：http://blog.roshka.com/2012/08/android-edittext-with-number-format.html
你需要使用DecimalFormat类与DecimalFormatSymbols类，检查以下方法，
public static String formatAmount(int num)
{
DecimalFormat decimalFormat = new DecimalFormat();
DecimalFormatSymbols decimalFormateSymbol = new DecimalFormatSymbols();
decimalFormateSymbol.setGroupingSeparator(',');
decimalFormat.setDecimalFormatSymbols(decimalFormateSymbol);
return decimalFormat.format(num);
}
不幸的是，代码无法正常运行。
它有两个问题：
我疯了解决它。最后，我来到这个在我的手机上运行良好的代码：
number text watcher.Java
import android.text.Editable;
import android.text.TextWatcher;
import android.text.method.DigitsKeyListener;
import android.util.Log;
import android.widget.EditText;
import java.math.RoundingMode;
import java.text.DecimalFormat;
import java.text.DecimalFormatSymbols;
import java.text.ParseException;
import java.util.Locale;
public class NumberTextWatcher
implements TextWatcher {
private static final String TAG = "NumberTextWatcher";
private final int numDecimals;
private String groupingSep;
private String decimalSep;
private boolean nonUsFormat;
private DecimalFormat df;
private DecimalFormat dfnd;
private boolean hasFractionalPart;
private EditText et;
private String value;
private String replicate(char ch, int n) {
return new String(new char[n]).replace("\0", "" + ch);
}
public NumberTextWatcher(EditText et, Locale locale, int numDecimals) {
et.setKeyListener(DigitsKeyListener.getInstance("0123456789.,"));
this.numDecimals = numDecimals;
DecimalFormatSymbols symbols = new DecimalFormatSymbols(locale);
char gs = symbols.getGroupingSeparator();
char ds = symbols.getDecimalSeparator();
groupingSep = String.valueOf(gs);
decimalSep = String.valueOf(ds);
String patternInt = "#,###";
dfnd = new DecimalFormat(patternInt, symbols);
String patternDec = patternInt + "." + replicate('#', numDecimals);
df = new DecimalFormat(patternDec, symbols);
df.setDecimalSeparatorAlwaysShown(true);
df.setRoundingMode(RoundingMode.DOWN);
this.et = et;
hasFractionalPart = false;
nonUsFormat = !decimalSep.equals(".");
value = null;
}
@Override
public void afterTextChanged(Editable s) {
Log.d(TAG, "afterTextChanged");
et.removeTextChangedListener(this);
try {
int inilen, endlen;
inilen = et.getText().length();
String v = value.replace(groupingSep, "");
Number n = df.parse(v);
int cp = et.getSelectionStart();
if (hasFractionalPart) {
int decPos = v.indexOf(decimalSep) + 1;
int decLen = v.length() - decPos;
if (decLen > numDecimals) {
v = v.substring(0, decPos + numDecimals);
}
int trz = countTrailingZeros(v);
StringBuilder fmt = new StringBuilder(df.format(n));
while (trz-- > 0) {
fmt.append("0");
}
et.setText(fmt.toString());
} else {
et.setText(dfnd.format(n));
}
endlen = et.getText().length();
int sel = (cp + (endlen - inilen));
if (sel > 0 && sel <= et.getText().length()) {
et.setSelection(sel);
} else {
// place cursor at the end?
et.setSelection(et.getText().length() - 1);
}
} catch (NumberFormatException | ParseException nfe) {
// do nothing?
}
et.addTextChangedListener(this);
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
Log.d(TAG, "beforeTextChanged");
value = et.getText().toString();
}
private int countTrailingZeros(String str) {
int count = 0;
for (int i = str.length() - 1; i >= 0; i--) {
char ch = str.charAt(i);
if ('0' == ch) {
count++;
} else {
break;
}
}
return count;
}
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
Log.d(TAG, "onTextChanged");
String newValue = s.toString();
String change = newValue.substring(start, start + count);
String prefix = value.substring(0, start);
String suffix = value.substring(start + before);
if (".".equals(change) && nonUsFormat) {
change = decimalSep;
}
value = prefix + change + suffix;
hasFractionalPart = value.contains(decimalSep);
Log.d(TAG, "VALUE: " + value);
}
}
然后用它来做：
Locale locale = new Locale("es", "AR"); // For example Argentina
int numDecs = 2; // Let's use 2 decimals
TextWatcher tw = new NumberTextWatcher(myEditText, locale, numDecs);
myEditText.addTextChangedListener(tw);