Android EditText字段和TextWatcher

我需要帮助。我不知道如何为may EditText字段执行TextWatcher。我想这样做：如果我在第一个字段中输入文本，我想计算其他字段的值。四个字段是可编辑的，所以若我将值放在一个EditText中，它会更改另一个字段中的值，从而导致循环和StackOverflowerError

它的源代码：

package com.example.hp.ptcalculator;

import android.app.Fragment;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.EditText;

public class Pt100Fragment extends Fragment{
    EditText Pt100Res, Pt100TempC, Pt100TempF, Pt100TempK, Pt100Sens, Pt100TolAA, Pt100TolA, Pt100TolB, Pt100TolC;
    View view;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        view = inflater.inflate(R.layout.pt100form, container, false);
        Pt100Sens = ((EditText) view.findViewById(R.id.Pt100SensEditText));
        Pt100TolAA = ((EditText) view.findViewById(R.id.Pt100TolAAEditText));
        Pt100TolA = ((EditText) view.findViewById(R.id.Pt100TolAEditText));
        Pt100TolB = ((EditText) view.findViewById(R.id.Pt100TolBEditText));
        Pt100TolC = ((EditText) view.findViewById(R.id.Pt100TolCEditText));
        Pt100Res = ((EditText) view.findViewById(R.id.Pt100ResEditText));
        Pt100TempC = ((EditText) view.findViewById(R.id.Pt100TempCEditText));
        Pt100TempF = ((EditText) view.findViewById(R.id.Pt100TempFEditText));
        Pt100TempK = ((EditText) view.findViewById(R.id.Pt100TempKEditText));
        Pt100Res.addTextChangedListener(watcher);
        Pt100TempC.addTextChangedListener(watcher);


        return view;
    }


    TextWatcher watcher = new TextWatcher() {
        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {
        }

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {
        }

        @Override
        public void afterTextChanged(Editable s) {
        }
    };




        public void calc1() {
            double R;
            double TC, TF, TK, Sens, TolAA, TolA, TolB, TolC;
            String tmp = Pt100Res.getText().toString();
            if (tmp.equals(""))
                R = 0;
            else
                R = Double.parseDouble(tmp);
            TC = res2temp(R);
            TF = 9 * TC / 5 + 32;
            TK = TC + 273.15;
            Sens = 0.2 / (res2temp(R * 1 + 0.1) - res2temp(R * 1 - 0.1));
            TolAA = 0.1 + 0.0017 * Math.abs(TC);
            TolA = 0.15 + 0.002 * Math.abs(TC);
            TolB = 0.30 + 0.005 * Math.abs(TC);
            TolC = 0.60 + 0.01 * Math.abs(TC);
            Pt100TempC.setText(String.valueOf(TC));
            Pt100TempF.setText(String.valueOf(TF));
            Pt100TempK.setText(String.valueOf(TK));
            Pt100Sens.setText(String.valueOf(Sens));
            Pt100TolAA.setText(String.valueOf(TolAA));
            Pt100TolA.setText(String.valueOf(TolA));
            Pt100TolB.setText(String.valueOf(TolB));
            Pt100TolC.setText(String.valueOf(TolC));
        }

        public void calc2() {
            double TC, TF, TK, Sens, TolAA, TolA, TolB, TolC, R;
            String tmp = Pt100TempC.getText().toString();
            if (tmp.equals(""))
                TC = 0;
            else
                TC = Double.parseDouble(tmp);
            R = temp2res(TC);
            TF = 9 * TC / 5 + 32;
            TK = TC + 273.15;
            Sens = 0.2 / (res2temp(R + 0.1) - res2temp(R - 0.1));
            TolAA = 0.1 + 0.0017 * Math.abs(TC);
            TolA = 0.15 + 0.002 * Math.abs(TC);
            TolB = 0.30 + 0.005 * Math.abs(TC);
            TolC = 0.60 + 0.01 * Math.abs(TC);
            Pt100Res.setText(String.valueOf(R));
            Pt100TempF.setText(String.valueOf(TF));
            Pt100TempK.setText(String.valueOf(TK));
            Pt100Sens.setText(String.valueOf(Sens));
            Pt100TolAA.setText(String.valueOf(TolAA));
            Pt100TolA.setText(String.valueOf(TolA));
            Pt100TolB.setText(String.valueOf(TolB));
            Pt100TolC.setText(String.valueOf(TolC));
        }

        public double temp2res(double temp) {
            double res;
            double coef_a = 3.90830e-3;
            double coef_b = -5.77500e-7;
            double coef_c = -4.18301e-12;
            double r0 = 100;
            if (temp > 0) {
                res = r0 * (1 + coef_a * temp + coef_b * Math.pow(temp, 2));
            } else if (temp < 0) {
                res = r0 * (1 + coef_a * temp + coef_b * Math.pow(temp, 2) + coef_c * (Math.pow(temp, 4) - 100 * Math.pow(temp, 3)));
            } else res = r0;
            return res;
        }

        public double res2temp(double res) {
            double coef_a = 3.90830e-3;
            double coef_b = -5.77500e-7;
            double coef_c = -4.18301e-12;
            double r0 = 100;
            double t, t0, Ohm2Temp;
            if (res < r0) {
                double pente = 0.38;
                double epsilon = 0.000000000001;
                int MaxIter = 100;
                t0 = -(r0 - res) / pente;
                for (int i = 1; i < MaxIter; i++) {
                    t = t0 - CVD(t0, res, r0) / CVDprime(t0, r0);
                    if (Math.abs(t - t0) <= epsilon) {
                        Ohm2Temp = t;
                        return Ohm2Temp;
                    } else t0 = t;
                }
                Ohm2Temp = 9999999;
            } else
                Ohm2Temp = (-coef_a + Math.sqrt(Math.pow(coef_a, 2) - 4 * coef_b * (1 - res / r0))) / (2 * coef_b);

            return Ohm2Temp;
        }

        public double CVD(double t, double Rt, double r0) {
            double coef_a = 3.90830e-3;
            double coef_b = -5.77500e-7;
            double coef_c = -4.18301e-12;
            double ff = r0 * (1 + coef_a * t + coef_b * Math.pow(t, 2) + coef_c * (t - 100) * Math.pow(t, 3)) - Rt;
            return ff;
        }

        public double CVDprime(double t, double R0) {
            double coef_a = 3.90830e-3;
            double coef_b = -5.77500e-7;
            double coef_c = -4.18301e-12;
            double fp = R0 * (coef_a + 2 * coef_b * t - 300 * coef_c * Math.pow(t, 2) + 4 * coef_c * Math.pow(t, 3));
            return fp;
        }


    }

---

但它导致java.lang.IllegalStateException:在id为“Pt100TempCEditText”的视图类android.widget.EditText上的onClick处理程序的活动类com.example.hp.ptcalculator.MainActivity中找不到方法true（View），原因是：java.lang.NoSuchMethodException:true[class android.View.View]

要解决此问题，您需要4个

TextWatcher

s-每个

EditText

一个

然后，在每个

TextWatcher

中，当您要执行计算时，从所有

EditText

s中删除

TextWatcher

s，执行计算，然后将其添加回去

这听起来像是一个很大的开销，但它不应该是一个明显的用户

是的，您可以从当前正在编辑的

TextView

中删除

TextWatcher

并将其添加回，但您可能只想从另一个

EditText

对象中删除所有“other”

TextWatcher

对象-更难实现，但技术上正确（正确处理快速事件）且更容易阅读（因为您没有编辑当前的

EditText

——所以只编辑其他文本）

要使用问答中的代码，请执行以下操作：

EditText Pt100Res = ((EditText) view.findViewById(R.id.Pt100ResEditText));
EditText Pt100TempC = ((EditText) view.findViewById(R.id.Pt100TempCEditText));
EditText Pt100TempF = ((EditText) view.findViewById(R.id.Pt100TempFEditText));
EditText Pt100TempK = ((EditText) view.findViewById(R.id.Pt100TempKEditText));
TextWatcher watcherRes;
TextWatcher watcherC;
TextWatcher watcherF;
TextWatcher watcherK;
watcherRes = new TextWatcher() {
        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {
            Pt100TempRes.removeTextChangedListener(watcherRes);
            Pt100TempC.removeTextChangedListener(watcherC);
            Pt100TempF.removeTextChangedListener(watcherF);
            Pt100TempK.removeTextChangedListener(watcherK);
            calc1();
            Pt100TempRes.addTextChangedListener(watcherRes);
            Pt100TempC.addTextChangedListener(watcherC);
            Pt100TempF.addTextChangedListener(watcherF);
            Pt100TempK.addTextChangedListener(watcherK);
        }

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {
        }

        @Override
        public void afterTextChanged(Editable s) {
        }
    };
    watcherC = new TextWatcher() {
        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {
            Pt100TempRes.removeTextChangedListener(watcherRes);
            Pt100TempC.removeTextChangedListener(watcher);
            Pt100TempF.removeTextChangedListener(watcherF);
            Pt100TempK.removeTextChangedListener(watcherK);
            calc2();
            Pt100TempRes.addTextChangedListener(watcherRes);
            Pt100TempC.addTextChangedListener(watcherC);
            Pt100TempF.addTextChangedListener(watcherF);
            Pt100TempK.addTextChangedListener(watcherK);
        }

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {
        }

        @Override
        public void afterTextChanged(Editable s) {
        }
    };
    watcherF = new TextWatcher() {
        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {
            Pt100TempRes.removeTextChangedListener(watcherRes);
            Pt100TempC.removeTextChangedListener(watcher);
            Pt100TempF.removeTextChangedListener(watcherF);
            Pt100TempK.removeTextChangedListener(watcherK);
            calc2();
            Pt100TempRes.addTextChangedListener(watcherRes);
            Pt100TempC.addTextChangedListener(watcherC);
            Pt100TempF.addTextChangedListener(watcherF);
            Pt100TempK.addTextChangedListener(watcherK);
        }

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {
        }

        @Override
        public void afterTextChanged(Editable s) {
        }
    };
    watcherK = new TextWatcher() {
        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {
            Pt100TempRes.removeTextChangedListener(watcherRes);
            Pt100TempC.removeTextChangedListener(watcher);
            Pt100TempF.removeTextChangedListener(watcherF);
            Pt100TempK.removeTextChangedListener(watcherK);
            calc2();
            Pt100TempRes.addTextChangedListener(watcherRes);
            Pt100TempC.addTextChangedListener(watcherC);
            Pt100TempF.addTextChangedListener(watcherF);
            Pt100TempK.addTextChangedListener(watcherK);
        }

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {
        }

        @Override
        public void afterTextChanged(Editable s) {
        }
    };

    Pt100Res.addTextChangedListener(watcherRes);
    Pt100TempC.addTextChangedListener(watcherC);
    Pt100TempF.addTextChangedListener(watcherF);
    Pt100TempK.addTextChangedListener(watcherK);

---

注意：任何更改都必须删除侦听器。因此，如果

calc1

没有更改

Pt100Res

，则不需要执行删除/添加行操作。我没有测试此代码，而是将其设置为通用代码（意思是我没有尝试找出“calc”是什么）函数实际上是这样的。

好的。所以我需要将文本观察者添加到first EditText，进行操作，当我编辑下一个EditText时，我应该删除first watcher并添加到编辑的EditText。我明白，但你能帮我吗？你能举个例子吗？我编辑了我的答案-希望它能帮助解释你需要做什么。

EditText Pt100Res = ((EditText) view.findViewById(R.id.Pt100ResEditText));
EditText Pt100TempC = ((EditText) view.findViewById(R.id.Pt100TempCEditText));
EditText Pt100TempF = ((EditText) view.findViewById(R.id.Pt100TempFEditText));
EditText Pt100TempK = ((EditText) view.findViewById(R.id.Pt100TempKEditText));
TextWatcher watcherRes;
TextWatcher watcherC;
TextWatcher watcherF;
TextWatcher watcherK;
watcherRes = new TextWatcher() {
        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {
            Pt100TempRes.removeTextChangedListener(watcherRes);
            Pt100TempC.removeTextChangedListener(watcherC);
            Pt100TempF.removeTextChangedListener(watcherF);
            Pt100TempK.removeTextChangedListener(watcherK);
            calc1();
            Pt100TempRes.addTextChangedListener(watcherRes);
            Pt100TempC.addTextChangedListener(watcherC);
            Pt100TempF.addTextChangedListener(watcherF);
            Pt100TempK.addTextChangedListener(watcherK);
        }

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {
        }

        @Override
        public void afterTextChanged(Editable s) {
        }
    };
    watcherC = new TextWatcher() {
        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {
            Pt100TempRes.removeTextChangedListener(watcherRes);
            Pt100TempC.removeTextChangedListener(watcher);
            Pt100TempF.removeTextChangedListener(watcherF);
            Pt100TempK.removeTextChangedListener(watcherK);
            calc2();
            Pt100TempRes.addTextChangedListener(watcherRes);
            Pt100TempC.addTextChangedListener(watcherC);
            Pt100TempF.addTextChangedListener(watcherF);
            Pt100TempK.addTextChangedListener(watcherK);
        }

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {
        }

        @Override
        public void afterTextChanged(Editable s) {
        }
    };
    watcherF = new TextWatcher() {
        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {
            Pt100TempRes.removeTextChangedListener(watcherRes);
            Pt100TempC.removeTextChangedListener(watcher);
            Pt100TempF.removeTextChangedListener(watcherF);
            Pt100TempK.removeTextChangedListener(watcherK);
            calc2();
            Pt100TempRes.addTextChangedListener(watcherRes);
            Pt100TempC.addTextChangedListener(watcherC);
            Pt100TempF.addTextChangedListener(watcherF);
            Pt100TempK.addTextChangedListener(watcherK);
        }

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {
        }

        @Override
        public void afterTextChanged(Editable s) {
        }
    };
    watcherK = new TextWatcher() {
        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {
            Pt100TempRes.removeTextChangedListener(watcherRes);
            Pt100TempC.removeTextChangedListener(watcher);
            Pt100TempF.removeTextChangedListener(watcherF);
            Pt100TempK.removeTextChangedListener(watcherK);
            calc2();
            Pt100TempRes.addTextChangedListener(watcherRes);
            Pt100TempC.addTextChangedListener(watcherC);
            Pt100TempF.addTextChangedListener(watcherF);
            Pt100TempK.addTextChangedListener(watcherK);
        }

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {
        }

        @Override
        public void afterTextChanged(Editable s) {
        }
    };

    Pt100Res.addTextChangedListener(watcherRes);
    Pt100TempC.addTextChangedListener(watcherC);
    Pt100TempF.addTextChangedListener(watcherF);
    Pt100TempK.addTextChangedListener(watcherK);