在 EditText 上使用 TextWatcher 在 android 中实时计算总数和总和?
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【中文标题】在 EditText 上使用 TextWatcher 在 android 中实时计算总数和总和?【英文标题】:Using a TextWatcher on a EditText to calculate the total and sum total in real time in android? 【发布时间】:2016-02-12 06:17:10 【问题描述】:在这里,我想采用来自我的数据库的默认值并将 setText 设置为该值并计算净费率和总额,否则如果用户编辑费率或收费,我想计算净费率和总额基于该值是实时的。
这是我用于计算和显示值的代码。
private void showItem(String json)
String itembarcode = "";
String itemdesc = "";
String weight = "";
String rate = "";
String making = "";
double wt = 0.0d;
double rt = 0.0d;
double mk = 0.0d;
try
JSONObject jsonObject = new JSONObject(json);
JSONArray result = jsonObject.getJSONArray(ParseBarcode.JSON_ARRAY);
JSONObject itemData = result.getJSONObject(0);
itembarcode = itemData.getString(ParseBarcode.KEY_BARCODE);
itemdesc = itemData.getString(ParseBarcode.KEY_DESC);
weight = itemData.getString(ParseBarcode.KEY_WEIGHT);
rate = itemData.getString(ParseBarcode.KEY_RATE);
making = itemData.getString(ParseBarcode.KEY_MAKING);
catch (JSONException e)
e.printStackTrace();
//table started
TableLayout.LayoutParams tableParams = new TableLayout.LayoutParams(TableLayout.LayoutParams.MATCH_PARENT, TableLayout.LayoutParams.WRAP_CONTENT);
TableRow.LayoutParams rowParams = new TableRow.LayoutParams(TableRow.LayoutParams.MATCH_PARENT, TableRow.LayoutParams.WRAP_CONTENT, 1f);
rowParams.setMargins(16, 0, 16, 0);
TableLayout tableLayout = new TableLayout(AddInvEst.this);
tableLayout.setLayoutParams(tableParams);
TableRow newRow = new TableRow(AddInvEst.this);
newRow.setLayoutParams(tableParams);
TextView barCode = new TextView(AddInvEst.this);
barCode.setLayoutParams(rowParams);
barCode.setGravity(Gravity.CENTER);
TextView itemDesc = new TextView(AddInvEst.this);
itemDesc.setLayoutParams(rowParams);
itemDesc.setGravity(Gravity.CENTER);
TextView weightLine = new TextView(AddInvEst.this);
weightLine.setLayoutParams(new TableRow.LayoutParams(TableRow.LayoutParams.MATCH_PARENT, TableRow.LayoutParams.WRAP_CONTENT, 0.75f));
weightLine.setGravity(Gravity.CENTER);
EditText rateAmount = new EditText(AddInvEst.this);
rateAmount.setLayoutParams(new TableRow.LayoutParams(TableRow.LayoutParams.MATCH_PARENT, TableRow.LayoutParams.WRAP_CONTENT, 0.5f));
rateAmount.setGravity(Gravity.CENTER);
// String rtAmt = rateAmount.getText().toString().trim();
EditText makingAmount = new EditText(AddInvEst.this);
makingAmount.setLayoutParams(new TableRow.LayoutParams(TableRow.LayoutParams.MATCH_PARENT, TableRow.LayoutParams.WRAP_CONTENT, 0.5f));
makingAmount.setGravity(Gravity.CENTER);
//String mkAmt = makingAmount.getText().toString().trim();
TextView netRate = new TextView(AddInvEst.this);
netRate.setLayoutParams(new TableRow.LayoutParams(TableRow.LayoutParams.MATCH_PARENT, TableRow.LayoutParams.WRAP_CONTENT, 0.5f));
netRate.setGravity(Gravity.CENTER);
TextView itemtotal = new TextView(AddInvEst.this);
itemtotal.setLayoutParams(rowParams);
itemtotal.setGravity(Gravity.CENTER);
wt = Double.parseDouble(weight);
rt = Double.parseDouble(rate);
mk = Double.parseDouble(making);
double NetRate = rt + mk;
double Total = (NetRate / 10) * wt;
barCode.setText(itembarcode);
itemDesc.setText(itemdesc);
weightLine.setText(weight);
rateAmount.setText(rate);
makingAmount.setText(making);
netRate.setText(NetRate + "");
itemtotal.setText(Total + "");
newRow.addView(barCode);
newRow.addView(itemDesc);
newRow.addView(weightLine);
newRow.addView(rateAmount);
newRow.addView(makingAmount);
newRow.addView(netRate);
newRow.addView(itemtotal);
itemTable.addView(newRow);
使用此代码,我可以计算净费率和总计,但我想将双精度值四舍五入到小数点后 4 位。另外,我将如何实时计算所有总计的总和。感谢任何帮助。提前致谢。 这是我的 xml 代码。
【问题讨论】:
@Krishnabhadra 你能帮我解决这个问题吗我已经阅读了你在***.com/questions/5645332/… 上的帖子我正在尝试实现类似的东西。 【参考方案1】:以下不是完整的代码,但可以让您了解实现。 您必须创建一个新的计算方法并显示结果 -
private void calculateAndShow(long wt, long rt, long mk)
double NetRate = rt + mk;
double Total = (NetRate / 10) * wt;
// Change the value here
barCode.setText(itembarcode);
itemDesc.setText(itemdesc);
weightLine.setText(weight);
rateAmount.setText(rate);
makingAmount.setText(making);
netRate.setText(NetRate + "");
itemtotal.setText(Total + "");
现在将这些行添加到您的方法之外 -
private TextWatcher rateTextWatcher = 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)
@Override
public void afterTextChanged(Editable s)
String rate = rateAmount.getText().toString();
newRate = Double.parseDouble(rate);
calculateAndShow(wt, newRate, mk);
;
private TextWatcher makingAmountTextWatcher = 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)
@Override
public void afterTextChanged(Editable s)
String makingAmount = makingAmount.getText().toString();
newMK = Double.parseDouble(makingAmount);
calculateAndShow(wt, rt, newMK);
;
这些 textwatcher 到你的 edittext 就像这样 -
EditText rateAmount = new EditText(AddInvEst.this);
rateAmount.setLayoutParams(new TableRow.LayoutParams(TableRow.LayoutParams.MATCH_PARENT, TableRow.LayoutParams.WRAP_CONTENT, 0.5f));
rateAmount.setGravity(Gravity.CENTER);
rateAmount.addTextChangedListener(rateTextWatcher);
EditText makingAmount = new EditText(AddInvEst.this);
makingAmount.setLayoutParams(new TableRow.LayoutParams(TableRow.LayoutParams.MATCH_PARENT, TableRow.LayoutParams.WRAP_CONTENT, 0.5f));
makingAmount.setGravity(Gravity.CENTER);
makingAmount.addTextChangedListener(makingAmountTextWatcher);
【讨论】:
谢谢@Rahul Chaurasia 是的@Rahul Chaurasia 这解决了我的问题,非常感谢!以上是关于在 EditText 上使用 TextWatcher 在 android 中实时计算总数和总和?的主要内容,如果未能解决你的问题,请参考以下文章
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