问题
I want to have an edit text with some value like 0.00 and cursor must be on the left side. when user press 1 it should be 1.00, when user presses 2 it should be 12.00, when user press "." cursor should move to the other side of decimal. After shifting to the other side of decimal when user press 3 it should be 12.30 and on pressing 4 it should be 12.34. Similarly on backpress it should be 12.30 -> 12.00 -> 1.00 -> 0.00.sample
import android.text.Editable;
import android.text.TextWatcher;
import android.view.KeyEvent;
import android.view.View;
import android.widget.EditText;
import java.util.Locale;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class AmountTextWatcher implements TextWatcher {
private EditText editText;
private int num_npt;
private String previous;
private boolean isBackSpacePressed;
public AmountTextWatcher(EditText editText, int num_npt) {
this.editText = editText;
this.num_npt = num_npt;
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
/*if (StorageUtils.INTERNAL_TRANSFER_AMOUNT != 0.00)
previous = String.format(Locale.getDefault(), "%.2f", StorageUtils.INTERNAL_TRANSFER_AMOUNT);
else*/
if (after < count) {
isBackSpacePressed = true;
} else {
isBackSpacePressed = false;
}
previous = editText.getText().toString();
}
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
editText.removeTextChangedListener(this);
if (isBackSpacePressed) {
String old_val = previous;
int point = old_val.indexOf(".");
if (point == -1) point = old_val.length();
int selectionStart = editText.getSelectionStart() + 1;
int selectionEnd = editText.getSelectionEnd();
String new_val = "";
if (selectionStart < selectionEnd) {
if (selectionEnd <= point) {
new_val = old_val.substring(0, selectionStart) + old_val.substring(selectionEnd);
} else if (selectionStart > point) {
new_val = old_val.substring(0, selectionStart) + "0" + old_val.substring(selectionEnd);
if (selectionEnd - selectionStart == num_npt) new_val += "0";
} else if (selectionStart <= point && selectionEnd > point) {
new_val = old_val.substring(0, selectionStart) + ".";
for (int z = 0; z < selectionEnd - point - 1; z++) new_val += "0";
new_val += old_val.substring(selectionEnd);
}
if (new_val.indexOf(".") == 0) new_val = "0" + new_val;
} else if (selectionStart == 1 && point == 1) {
new_val = "0" + old_val.substring(1);
selectionStart = 0;
} else if (selectionStart > 0 && selectionStart <= point) {
new_val = old_val.substring(0, selectionStart - 1) + old_val.substring(selectionStart);
selectionStart--;
} else if (selectionStart == point + 1) {
new_val = old_val;
selectionStart = point;
} else if (selectionStart > point + 1) {
new_val = old_val.substring(0, selectionStart - 1) + old_val.substring(selectionStart) + "0";
selectionStart--;
} else {
new_val = old_val;
}
if (new_val.equals("")) new_val = "0";
editText.setText(new_val);
editText.setSelection(selectionStart);
editText.addTextChangedListener(this);
} else {
int point = previous.indexOf(".");
if (point == -1) point = previous.length();
int selectionStart = editText.getSelectionStart() - 1;
int selectionEnd = editText.getSelectionEnd() - 1;
String c = s.subSequence(start, start + count).toString();
if (c.equals("-") || c.equals(" ")) {
editText.setText(previous);
editText.setSelection(selectionStart);
editText.addTextChangedListener(this);
return;
}
String new_val = "";
if (selectionStart > -1 && selectionStart < editText.getText().length() - 1) {
if (c != null && c.length() > 0) {
if (c.equals(",")) c = ".";
if (Character.isDigit(c.charAt(0)) || c.equals(".")) {
if (selectionStart < selectionEnd) {
if (selectionEnd <= point) {
new_val = previous.substring(0, selectionStart) + c + previous.substring(selectionEnd);
} else if (selectionStart > point) {
new_val = previous.substring(0, selectionStart) + c + previous.substring(selectionEnd);
for (int x = 0; x < selectionEnd - selectionStart - 1; x++)
new_val += "0";
} else if (selectionStart <= point && selectionEnd > point && !c.equals(".")) {
new_val = previous.substring(0, selectionStart) + c + ".";
for (int y = 0; y < selectionEnd - point - 1; y++)
new_val += "0";
new_val += previous.substring(selectionEnd);
}
} else if ((num_npt == 0 && previous.equals("0")) || (previous.substring(0, 2).equals("0.") && selectionStart == 0)) {
if (c.equals(".")) {
new_val = previous;
editText.setSelection(0);
} else
new_val = c + previous.substring(1);
} else if (selectionStart > point && selectionStart <= point + num_npt) {
if (c.equals(".")) {
if (editText.getSelectionStart() > previous.indexOf("."))
new_val = previous.substring(0, selectionStart) + previous.substring(selectionStart);
else
new_val = previous.substring(0, selectionStart - 1) + c + previous.substring(selectionStart);
editText.setSelection(selectionStart - 1);
} else
new_val = previous.substring(0, selectionStart) + c + previous.substring(selectionStart + 1);
}
// this is the code where our edittext lags :(
else {
if (c.equals("."))
if (editText.getSelectionStart() - 1 == 0) {
if (c.equals("."))
new_val = previous.substring(0, 1) + previous.substring(selectionEnd + 1);
else
new_val = previous.substring(0, 1) + c + previous.substring(selectionEnd + 2);
} else {
if (selectionStart > 0 && selectionStart < previous.indexOf("."))
new_val = previous.substring(0, selectionStart + 1) + previous.substring(selectionEnd + 1);
else
new_val = previous.substring(0, selectionStart) + c + previous.substring(selectionEnd + 1);
}
else
new_val = previous.substring(0, selectionStart) + c + previous.substring(selectionEnd);
if (new_val.substring(new_val.length() - 1).equals("."))
new_val = new_val.substring(0, new_val.length() - 1);
}
// *********//
if (new_val.substring(0, 1).equals("0") && !new_val.substring(0, 2).equals("0.")) {
new_val = new_val.substring(1);
selectionStart--;
}
Pattern pattern = Pattern.compile("^[0-9]+(\\.[0-9]{0," + num_npt + "})?$");
Matcher matcher = pattern.matcher(new_val);
boolean doNothing = false;
if (matcher.matches()) {
editText.setText(new_val);
if (!c.equals("."))
selectionStart++;
else if (c.equals(".") && selectionStart == previous.indexOf("."))
selectionStart++;
editText.setSelection(selectionStart);
} else if (c.equals(".")) {
selectionStart++;
editText.setSelection(selectionStart);
}
editText.addTextChangedListener(this);
}
} else {
editText.setText(previous);
editText.setSelection(selectionStart);
editText.addTextChangedListener(this);
}
} else {
int length = editText.getText().length();
if (selectionStart < 0)
selectionStart = 0;
else if (selectionStart > length || selectionEnd < length)
selectionStart = length - 1;
editText.setText(previous);
editText.setSelection(selectionStart);
editText.addTextChangedListener(this);
}
}
}
@Override
public void afterTextChanged(Editable s) {
}
}
回答1:
Try to use DecimalFormat Class in Java. It may help you in a better way.
String pattern = "##.##";
DecimalFormat decimalFormat = new DecimalFormat(pattern);
String output = decimalFormat.format( YOUR NUMBER HERE );
回答2:
You can use String.format("%.2f", d) inside your onTextChanged to format
Update 1:
etText.setFilters(new InputFilter[]{new DecimalDigitsInputFilter(5, 2)});
class DecimalDigitsInputFilter implements InputFilter {
private Pattern mPattern;
DecimalDigitsInputFilter(int digitsBeforeZero, int digitsAfterZero) {
mPattern = Pattern.compile("[0-9]{0," + (digitsBeforeZero - 1) + "}+((\\.[0-9]{0," + (digitsAfterZero - 1) + "})?)||(\\.)?");
}
@Override
public CharSequence filter(CharSequence source, int start, int end, Spanned dest, int dstart, int dend) {
Matcher matcher = mPattern.matcher(dest);
if (!matcher.matches())
return "";
return null;
}
}
回答3:
xml
<EditText
android:id="@+id/et_des_input"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:inputType="numberDecimal"
android:gravity="right"
android:text="0.00"
android:digits=".0123456789"/>
Set TextWacher
EditText et_des_input = (EditText) findViewById(R.id.et_des_input);
et_des_input.addTextChangedListener(new AmountTextWatcher(et_des_input, 2));
TextWacher class is same as you post. It is working as you ask for.
See the output
回答4:
I have made this solution for two decimal places. Please check it guys. this works for two decimal places.
public class TxLabzTextWatcher implements TextWatcher {
EditText editText;
String tempText = "";
StringBuilder stringBuilder;
Context ctx;
boolean isBackSpacePressed = false;
int digitsAfteZero;
int count;
boolean isFirstDigitBeforeDecimalZero = true;
public TxLabzTextWatcher(Context context, EditText editText, int digitsAfterZero) {
this.editText = editText;
tempText = editText.getText().toString();
stringBuilder = new StringBuilder();
this.ctx = context;
this.digitsAfteZero = digitsAfterZero;
count = 0;
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
if (after < count) {
isBackSpacePressed = true;
} else {
isBackSpacePressed = false;
}
}
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
editText.removeTextChangedListener(this);
if (stringBuilder.toString().isEmpty()) {
stringBuilder.append("0.00");
}
if (!isBackSpacePressed) {
editText.removeTextChangedListener(this);
stringBuilder.setLength(0);
stringBuilder.append(s);
char ch = s.charAt(start + before);
if (!isClickDot(ch)) {
if (stringBuilder.length() > 0 && stringBuilder.indexOf(".") - 1 == editText.getSelectionStart() && stringBuilder.charAt(stringBuilder.indexOf(".") - 1) == '0' && ch != '0' && isFirstDigitBeforeDecimalZero) {
stringBuilder.deleteCharAt(stringBuilder.indexOf(".") - 1);
editText.setText(stringBuilder.toString());
editText.setSelection(editText.getText().length() - 3);
isFirstDigitBeforeDecimalZero = false;
} else if (ch == '0' && stringBuilder.indexOf(".") - 1 == editText.getSelectionStart()) {
stringBuilder.deleteCharAt(stringBuilder.indexOf(".") - 1);
editText.setText(stringBuilder.toString());
editText.setSelection(editText.getText().length() - 3);
isFirstDigitBeforeDecimalZero = false;
}
}
// if i press dot then move to the other side of
if (isClickDot(ch) && StringUtils.countMatches(stringBuilder.toString(), ".") >= 1) {
stringBuilder.deleteCharAt(s.toString().indexOf('.'));
editText.setText(stringBuilder.toString());
editText.setSelection(s.toString().indexOf('.') + 1);
}
// replace first digit after decimal
if (stringBuilder.indexOf(".") + 2 == editText.getSelectionStart() && !isClickDot(ch)) {
int currIndex = stringBuilder.indexOf(".") + 1;
stringBuilder.deleteCharAt(currIndex + 1);
editText.setText(stringBuilder.toString());
editText.setSelection(currIndex + 1);
count++;
}
// replace last digit after decimal
if (stringBuilder.indexOf(".") + 3 == editText.getSelectionStart() && !isClickDot(ch)) {
int currIndex = stringBuilder.indexOf(".") + 2;
stringBuilder.deleteCharAt(currIndex + 1);
editText.setText(stringBuilder.toString());
editText.setSelection(currIndex + 1);
count++;
}
// if string builder after decimal have more than 2 length then delete it
if (editText.getSelectionEnd() == stringBuilder.length() && stringBuilder.subSequence(stringBuilder.indexOf(".") + 1, stringBuilder.length()).length() > digitsAfteZero) {
stringBuilder.deleteCharAt(editText.getSelectionEnd() - 1);
editText.setText(stringBuilder.toString());
editText.setSelection(stringBuilder.length());
}
editText.addTextChangedListener(this);
} else {
editText.removeTextChangedListener(this);
if (s.toString().length() == 3 && s.toString().contains(".") && s.toString().substring(0, s.toString().indexOf('.')).length() == 0) {
// place zero befor decimal
String zeroBeforeDecimal = "0" + s.toString();
stringBuilder.setLength(0);
stringBuilder.append(zeroBeforeDecimal);
editText.setText(stringBuilder.toString());
isFirstDigitBeforeDecimalZero = true;
}
// if cursor is moved to other side of decimal now move it to left side of decimal
if (stringBuilder.toString().contains(".") && editText.getSelectionStart() == stringBuilder.indexOf(".")) {
stringBuilder.setLength(0);
stringBuilder.append(s);
stringBuilder.insert(stringBuilder.length() - 2, ".");
editText.setText(stringBuilder.toString());
editText.setSelection(stringBuilder.indexOf("."));
}
// if cursor is after one digit after decimal
if (stringBuilder.indexOf(".") + 1 == editText.getSelectionStart()) {
int currIndex = stringBuilder.indexOf(".") + 1;
stringBuilder.deleteCharAt(currIndex);
stringBuilder.insert(currIndex, "0");
editText.setText(stringBuilder.toString());
editText.setSelection(currIndex - 1);
}
// if cursor is on last digit then replace it with zero
if (stringBuilder.indexOf(".") + 2 == editText.getSelectionStart()) {
int currIndex = stringBuilder.indexOf(".") + 2;
stringBuilder.deleteCharAt(currIndex);
stringBuilder.insert(currIndex, "0");
editText.setText(stringBuilder.toString());
editText.setSelection(currIndex);
}
editText.addTextChangedListener(this);
}
}
@Override
public void afterTextChanged(Editable arg0) {
}
boolean isClickDot(char dot) {
if (dot == '.')
return true;
return false;
}
}
来源：https://stackoverflow.com/questions/59387099/decimal-input-edittext-in-java