汇率转换app小程序（附源码）

The last step is to actually code the currency conversion. There's not much to it, you can look up your GUI elements with: this.findViewById(R.id.<id>). Here is the complete code for the CurrencyConverter activity: import android.app.Activity; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.RadioButton; import android.widget.TextView; public class CurrencyConverter extends Activity implements OnClickListener { TextView dollars; TextView euros; RadioButton dtoe; RadioButton etod; Button convert; /** Called when the activity is first created. */ @Override public void onCreate(Bundle icicle) { super.onCreate(icicle); setContentView(R.layout.main); dollars = (TextView)this.findViewById(R.id.dollars); euros = (TextView)this.findViewById(R.id.euros); dtoe = (RadioButton)this.findViewById(R.id.dtoe); dtoe.setChecked(true); etod = (RadioButton)this.findViewById(R.id.etod); convert = (Button)this.findViewById(R.id.convert); convert.setOnClickListener(this); } public void onClick(View v) { if (dtoe.isChecked()) { convertDollarsToEuros(); } if (etod.isChecked()) { convertEurosToDollars(); } } protected void convertDollarsToEuros() { double val = Double.parseDouble(dollars.getText().toString()); // in a real app, we'd get this off the 'net euros.setText(Double.toString(val*0.67)); } protected void convertEurosToDollars() { double val = Double.parseDouble(euros.getText().toString()); // in a real app, we'd get this off the 'net dollars.setText(Double.toString(val/0.67)); } }