java - java中的十进制输入edittext

Question

我想要一个具有诸如 0.00 之类的值的编辑文本，并且光标必须位于左侧。当用户按 1 时，它应该是 1.00，当用户按 2 时，它应该是 12.00，当用户按“.”时，它应该是 12.00。光标应移动到小数点的另一侧。当用户按 3 时，移动到小数点的另一侧后，它应该是 12.30，按 4 时，它应该是 12.34。同样，在背压上，它应该是 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) {

    }
}

Answer 1

尝试在Java中使用DecimalFormat类。它可能会以更好的方式帮助您。

String pattern = "##.##";
DecimalFormat decimalFormat = new DecimalFormat(pattern);
String output = decimalFormat.format( YOUR NUMBER HERE );