如何基于EditText更新自定义ArrayAdapter的TextView？

Question

我有一个自定义的ArrayAdapter，它是一个水平的LinearLayout，包含02 EditText字段和01 TextView .....所有设置为/显示numberDecimals。

我只需要在任何EditText字段中输入数字时，TextView中将显示两个数字（EditText 1 & EditText 2）的乘积。

我已经尝试了OnFocusChangedListener和TextChangedListener，但TextView在活动条目期间没有更新。它没有显示任何东西。

我是编程新手，所以无法找到任何其他解决方案。 在此先感谢！

下面是适配器代码：

TextView labelView; 
EditText ratioView; 
EditText rateView; 
TextView avgView; 


public FibresAdapter(Activity context, ArrayList<Fibres> fibresList) { 
    super(context, 0, fibresList); 
} 

@NonNull 
@Override 
public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) { 
    if (convertView == null) { 
     convertView = LayoutInflater.from(getContext()).inflate(R.layout.list_item, parent, false); 
    } 
    final Fibres currentFibre = getItem(position); 

    labelView = (TextView) convertView.findViewById(R.id.label); 
    labelView.setText(currentFibre.fibreLabel); 

    ratioView = (EditText) convertView.findViewById(ratio); 
    rateView = (EditText) convertView.findViewById(R.id.rate); 
    avgView = (TextView) convertView.findViewById(R.id.avg); 

    ratioView.addTextChangedListener(new TextWatcher() { 
     @Override 
     public void beforeTextChanged(CharSequence s, int start, int count, int after) { 

     } 

     @Override 
     public void onTextChanged(CharSequence s, int start, int before, int count) { 
      if (s.toString().length() > 0) { 
       currentFibre.fibreRatio = Double.parseDouble(s.toString()); 
       avgView.setText("Testing"); 
      } else { 
       currentFibre.fibreRatio = 0; 
      } 
     } 

     @Override 
     public void afterTextChanged(Editable s) { 

     } 
    }); 

    rateView.addTextChangedListener(new TextWatcher() { 
     @Override 
     public void beforeTextChanged(CharSequence s, int start, int count, int after) { 

     } 

     @Override 
     public void onTextChanged(CharSequence s, int start, int before, int count) { 
      if (s.toString().length() > 0) { 
       currentFibre.fibreRate = Double.parseDouble(s.toString()); 
       avgView.setText("Testing"); 
      } else { 
       currentFibre.fibreRate = 0; 
      } 
     } 

     @Override 
     public void afterTextChanged(Editable s) { 

     } 
    }); 

    return convertView; 
} 

下面是活动代码：

double totalAvg; 
double totalRatio; 

TextView totalAvgView; 
TextView totalRatioView; 

static ArrayList<Fibres> fibres; 


@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.fibres_list); 

    fibres = new ArrayList<>(); 
    int x = 0; 

    while (x < Fibres.fibCatArray.length) { 
     fibres.add(new Fibres(Fibres.fibCatArray[x])); 
     x++; 
    } 

    ListView listView = (ListView) findViewById(R.id.list); 
    FibresAdapter adapter = new FibresAdapter(this, fibres); 

    listView.setAdapter(adapter); 

    totalRatioView = (TextView) findViewById(R.id.total_ratio); 
    totalAvgView = (TextView) findViewById(R.id.total_avg); 

} 

public void displayTotals() { 
    totalRatio = 0; 
    totalAvg = 0; 

    for (Fibres materials : fibres) { 
     totalRatio += materials.fibreRatio; 
     totalAvg += (materials.fibreRatio/100 * materials.fibreRate); 
    } 
    totalRatioView.setText(totalRatio + ""); 
    totalAvgView.setText(totalAvg + ""); 

} 

public boolean validateData() { 
    if (totalRatio != 100) { 
     Toast.makeText(this, "Total should be 100%!", Toast.LENGTH_SHORT).show(); 
     return false; 
    } 

    for (Fibres materials : fibres) { 
     if (materials.fibreRatio > 1 && materials.fibreRate <= 0) { 
      Toast.makeText(this, "Enter both Ratio & Rate!", Toast.LENGTH_SHORT).show(); 
      return false; 
     } 
    } 
    return true; 
} 

Answer 1

在你的适配器添加addTextChangedListener双方的EditText和使用textView.setText（）内部的。像这样的东西。

editText1.addTextChangedListener(new TextWatcher() { 

    @Override 
    public void afterTextChanged(Editable s) {} 

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

    @Override  
    public void onTextChanged(CharSequence s, int start, 
    int before, int count) { 
     if(s.length() != 0) 
     textView.setText(""); 
    } 
    });