Java 如何读取微调器并从edittext获取数据到textview?
我想知道我的代码在哪里出错。此活动应类似于单元转换器。有两个微调器用于选择单位,一个edittest用于插入值,另一个textview用于显示结果。当我插入一个值并按下按钮将其转换时,我会非常激动。你能帮助我吗?谢谢你,对不起我的英语Java 如何读取微调器并从edittext获取数据到textview?,java,android,android-layout,android-edittext,spinner,Java,Android,Android Layout,Android Edittext,Spinner,我想知道我的代码在哪里出错。此活动应类似于单元转换器。有两个微调器用于选择单位,一个edittest用于插入值,另一个textview用于显示结果。当我插入一个值并按下按钮将其转换时,我会非常激动。你能帮助我吗?谢谢你,对不起我的英语 public class lunghezze extends Activity implements OnClickListener { EditText et1; TextView tv1; Spinner spinner1,spinner2;
public class lunghezze extends Activity implements OnClickListener {
EditText et1;
TextView tv1;
Spinner spinner1,spinner2;
Button btnAdd;
String oper = "";
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.converter);
Spinner spinner1 = (Spinner) findViewById(R.id.spinner1);
Spinner spinner2 = (Spinner) findViewById(R.id.spinner2);
ArrayAdapter<CharSequence> adapter1 = ArrayAdapter.createFromResource(this,R.array.lunghezza, android.R.layout.simple_spinner_item);
adapter1.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner1.setAdapter(adapter1);
ArrayAdapter<CharSequence> adapter2 = ArrayAdapter.createFromResource(this,R.array.lunghezza, android.R.layout.simple_spinner_item);
adapter2.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner2.setAdapter(adapter2);
// find the elements
et1 = (EditText) findViewById(R.id.editText1);
btnAdd = (Button) findViewById(R.id.button1);
tv1 = (TextView) findViewById(R.id.textView4);
// set a listener
btnAdd.setOnClickListener(this);
}
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
double num1 = 0;
double resdelta = 0;
double res = 0;
double resx2 = 0;
if (TextUtils.isEmpty(et1.getText().toString())) {
return;
}
String a = et1.getText().toString().trim();
num1 = a.isEmpty()? Double.NaN:Double.parseDouble(a);
switch (v.getId()) {
case R.id.button1:
String s1 = spinner1.getSelectedItem().toString();
String s2 = spinner2.getSelectedItem().toString();
if (s1 + s2 == "IardeIarde"){
tv1.setText("" + num1);
} else {
}
break;
default:
break;
您已经将微调器声明为类成员。所以只需在onCreate中初始化它 改变
Spinner spinner1,spinner2;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.converter);
Spinner spinner1 = (Spinner) findViewById(R.id.spinner1);
Spinner spinner2 = (Spinner) findViewById(R.id.spinner2);
... //rest of the code
到
此外,要比较字符串,请使用.equals或.equalsIgnoreCase代替==
Spinner spinner1,spinner2;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.converter);
Spinner spinner1 = (Spinner) findViewById(R.id.spinner1);
Spinner spinner2 = (Spinner) findViewById(R.id.spinner2);
... //rest of the code
Spinner spinner1,spinner2;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.converter);
spinner1 = (Spinner) findViewById(R.id.spinner1);
spinner2 = (Spinner) findViewById(R.id.spinner2);
... //rest of the code