我正在编写和 android 应用程序，我的代码是货币转换器，当我输入要转换的金额时，什么都不会改变 - 转换后的金额为零 -
我不知道我的代码有什么问题：
这是我正在编写的代码：
public class Currency_convert extends Activity
{
/** Called when the activity is first created. */
float inputValue;
Handler h;
static int decimalsize = 2;
public DecimalFormat df = new DecimalFormat();
String US = "USD";
String EURO = "EUR";
String INR = "INR";
String AUD = "AUD";
String GBP = "GBP";
public double dUS;// = 0.0;
public double dEURO = 1.0;
public double dINR;// = 0.0;
public double dAUD;// = 0.0;
public double dGBP;// = 0.0;
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.currency);
boolean rateupdate = false;
AbsoluteLayout al = (AbsoluteLayout) findViewById(R.id.AbsoluteLayout01);
al.setBackgroundColor(Color.LTGRAY);
final EditText amount = (EditText) findViewById(R.id.txt1);
final EditText etResult = (EditText) findViewById(R.id.txt2);
final Spinner sp1 = (Spinner) findViewById(R.id.spinerr1);
final Spinner sp2 = (Spinner) findViewById(R.id.spinerr2);
final InputMethodManager imm = (InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE);
ArrayAdapter adapter = ArrayAdapter.createFromResource(this, R.array.currency, android.R.layout.simple_spinner_item);
final Button btn = (Button) findViewById(R.id.bb1);
amount.setText("0.0");
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
// adapter.setDropDownViewResource(android.R.layout.)
sp1.setAdapter(adapter);
sp2.setAdapter(adapter);
rateupdate = getRate();
if(rateupdate)
btn.setText("Currency Rate updated");
else
btn.setText("Updated Currency Rate ");
//btn.setText(Boolean.toString(rateupdate));
OnClickListener ltouch = new OnClickListener()
{
public void onClick(View v)
{
// TODO Auto-generated method stub
//getRate();
}
};;;
btn.setOnClickListener(ltouch );
OnItemClickListener itemClick = new OnItemClickListener()
{
@Override
public void onItemClick(AdapterView<?> parent, View view, int position,long id)
{
int curr1 = (int) sp1.getSelectedItemId();
int curr2 = (int) sp2.getSelectedItemId();
double result = Convert(curr1, curr2, amount.getText().toString());
etResult.setText(Double.toString(result));
}
};
OnItemSelectedListener ItemSelectListener = new OnItemSelectedListener()
{
@Override
public void onItemSelected(AdapterView<?> parent, View view,int position, long id)
{
try
{
int curr1 = (int) sp1.getSelectedItemId();
int curr2 = (int) sp2.getSelectedItemId();
double result = Convert(curr1, curr2, amount.getText().toString());
etResult.setText(Double.toString(result));
}
catch(Exception e)
{
}
}
@Override
public void onNothingSelected(AdapterView<?> arg0)
{
// TODO Auto-generated method stub
}
};
sp1.setOnItemSelectedListener(ItemSelectListener);
sp2.setOnItemSelectedListener(ItemSelectListener);
amount.addTextChangedListener(new TextWatcher()
{
@Override
public void onTextChanged(CharSequence s, int start, int before, int count)
{
// TODO Auto-generated method stub
int length = s.length();
if(length == 0)
//amount.setText("0.0");
s = "0.0";
int curr1 = (int) sp1.getSelectedItemId();
int curr2 = (int) sp2.getSelectedItemId();
//double result = Convert(curr1, curr2, amount.getText().toString());
double result = Convert(curr1, curr2, s.toString());
etResult.setText(Double.toString(result));
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count,int after)
{
// TODO Auto-generated method stub
}
@Override
public void afterTextChanged(Editable s)
{
// TODO Auto-generated method stub
}
});
OnTouchListener l = new OnTouchListener()
{
@Override
public boolean onTouch(View v, MotionEvent event)
{
// TODO Auto-generated method stub
imm.hideSoftInputFromWindow(amount.getWindowToken(),0);//
return true;
}
};
al.setOnTouchListener(l);
sp1.setSelection(4);
sp2.setSelection(0);
}
protected Double Convert(int currency_from_index, int currency_to_index, String s_amount)
{
// TODO Auto-generated method stub
Double result = 0.0;
Double amount = Double.parseDouble(s_amount);
Double source = 0.0;
Double destination = 0.0;
if((dUS * dAUD * dINR * dGBP * dEURO) == 0)
{
result = 0.0;
return result;
}
else
{
switch (currency_from_index)
{
case 0:
source = dUS;
break;
case 1:
source = dAUD;
break;
case 2:
source = dINR;
break;
case 3:
source = dGBP;
break;
case 4:
source = dEURO;
break;
default:
break;
}
switch (currency_to_index)
{
case 0:
destination = dUS;
break;
case 1:
destination = dAUD;
break;
case 2:
destination = dINR;
break;
case 3:
destination = dGBP;
break;
case 4:
destination = dEURO;
break;
default:
break;
}
result = amount*destination/source;
Math.round(result);
try
{
df.setMaximumFractionDigits(decimalsize);
df.setMinimumFractionDigits(decimalsize);
String str_result = df.format(result);
result = Double.parseDouble(str_result);
}
catch(Exception e)
{
}
return result;
}
}
public boolean getRate()
{
//ConversionRate cr = new ConversionRate();
try
{
//URL url = new URL(eText.getText().toString());
String path = "http://www.ecb.int/stats/eurofxref/eurofxref-daily.xml";
URL url = new URL(path);
URLConnection conn = url.openConnection();
// Get the response
BufferedReader rd = new BufferedReader(new InputStreamReader(conn.getInputStream()));
XmlPullParserFactory factory = XmlPullParserFactory.newInstance();
factory.setNamespaceAware(true);
XmlPullParser xpp = factory.newPullParser();
//xpp.setInput( new StringReader ( "<foo>Hello World!</foo>" ) );
xpp.setInput(rd);
int eventType = xpp.getEventType();
while (eventType != XmlPullParser.END_DOCUMENT)
{
if(eventType == XmlPullParser.START_DOCUMENT)
{
//System.out.println("Start document");
//tView.append("Start document");
}
else if(eventType == XmlPullParser.END_DOCUMENT)
{
//System.out.println("End document");
//tView.append("End document");
}
else if(eventType == XmlPullParser.START_TAG)
{
//System.out.println("Start tag "+xpp.getName());
//tView.append("Start tag "+xpp.getName());
//tView.append("Attribute Count = " + xpp.getAttributeCount());
if(xpp.getAttributeCount() > 1)
{
/*tView.append("Currency = " + xpp.getAttributeValue(0) + "\t");
tView.append("Rate = " + xpp.getAttributeValue(1));
tView.append("\n");*/
//cr.setName(xpp.getAttributeValue(0));
//cr.setRate(Double.parseDouble(xpp.getAttributeValue(1)));
if(xpp.getAttributeValue(0).equals(US))// toString()== US)
Currency_convert.this.dUS = Double.parseDouble(xpp.getAttributeValue(1));
else if(xpp.getAttributeValue(0).equals(INR))// .toString() == "INR")
dINR = Double.parseDouble(xpp.getAttributeValue(1));
else if(xpp.getAttributeValue(0).equals(GBP))// .toString() == "GBP")
dGBP = Double.parseDouble(xpp.getAttributeValue(1));
else if(xpp.getAttributeValue(0).equals(AUD))// .toString() == "AUD")
dAUD = Double.parseDouble(xpp.getAttributeValue(1));
}
}
else if(eventType == XmlPullParser.END_TAG)
{
//System.out.println("End tag "+xpp.getName());
//tView.append("End tag "+xpp.getName());
}
else if(eventType == XmlPullParser.TEXT)
{
//System.out.println("Text "+xpp.getText());
//tView.append("Text "+xpp.getText());
}
eventType = xpp.next();
}
return true;
}
catch(Exception e)
{
e.printStackTrace();
return false;
}
}
}
这是xml文件：
<?xml version="1.0" encoding="utf-8"?>
<AbsoluteLayout android:id="@+id/AbsoluteLayout01" android:layout_width="fill_parent" android:layout_height="fill_parent" xmlns:android="http://schemas.android.com/apk/res/android">
<EditText android:id="@+id/txt1" android:text="@+id/EditText01" android:layout_height="wrap_content" android:layout_width="wrap_content" android:layout_y="10dip" android:numeric="decimal" android:singleLine="true" android:ems="8" android:hint="Enter amount" android:layout_x="5dip"></EditText>
<EditText android:id="@+id/txt2" android:layout_height="wrap_content" android:layout_width="wrap_content" android:text="@+id/EditText02" android:editable="false" android:enabled="true" android:singleLine="true" android:layout_x="5dip" android:ems="8" android:layout_y="69dip"></EditText>
<Spinner android:id="@+id/spinerr1" android:layout_height="wrap_content" android:layout_width="wrap_content" android:layout_y="10dip" android:layout_x="180dip"></Spinner>
<Spinner android:layout_y="69dip" android:id="@+id/spinerr2" android:layout_height="wrap_content" android:layout_width="wrap_content" android:layout_x="180dip"></Spinner>
<Button android:layout_height="wrap_content" android:layout_width="wrap_content" android:id="@+id/bb1" android:layout_x="50dip" android:text="Update Currency Rates" android:layout_y="120dip"></Button>
</AbsoluteLayout>
我在 LogCat 中没有收到任何错误！！！