我知道很多人问过这个问题，但是我似乎无法使它正常工作。
我正在尝试从editTextBirth获取字符串，并将其解析为最新的日期，并由此计算出用户的年龄，将结果投射到editTextAge上（出于个人原因，我希望将其保留为EditText，而不是TextView）。
这是到目前为止我得到的：
public class AddPatientActivity extends AppCompatActivity implements View.OnClickListener{
private static final int DATE_DIALOG_ID = R.layout.birthdaypicker;
private EditText editTextName;
private EditText editTextBirth;
private EditText editTextAge;
private EditText editTextComp;
private SimpleDateFormat dateFormat;
private Calendar c = Calendar.getInstance();
private Calendar now = Calendar.getInstance();
private Button buttonCalc;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_add_patient);
editTextName = (EditText) findViewById(R.id.editTextName);
editTextAge = (EditText) findViewById(R.id.editTextAge);
editTextBirth = (EditText) findViewById(R.id.editTextBirth);
editTextComp = (EditText) findViewById(R.id.editTextComp);
buttonCalc = (Button) findViewById(R.id.buttonCalc);
dateFormat = new SimpleDateFormat("dd/MM/yyyy");
}
@Override
public void onClick(View view) {
//if calc button is pressed
if (view == buttonCalc) {
String date = editTextBirth.getText().toString();
try {
c.setTime(dateFormat.parse(date));
int age = now.get(Calendar.YEAR) - c.get(Calendar.YEAR);
if (now.get(Calendar.DAY_OF_YEAR) < c.get(Calendar.DAY_OF_YEAR)) {
age--;
}
String idade = Integer.toString(age);
editTextAge.setText(idade);
} catch (ParseException e) {
e.printStackTrace();
}
}
}
不幸的是，当我单击buttonCalc或将输入格式从ddMMyyyy（editTextBirth的显示方式）更改为dd / MM / yyyy时，什么也没有发生。
最佳答案
您创建了onClick事件，但从未将其明确分配给按钮。
在您的按钮声明下面添加以下代码段：
buttonCalc.setOnClickListener(this);
@Pavneet_Singh也正确。您需要比较视图ID，而不仅仅是按钮。
这是您最终的解决方案应为：
public class AddPatientActivity extends AppCompatActivity implements View.OnClickListener{
private static final int DATE_DIALOG_ID = R.layout.birthdaypicker;
private EditText editTextName;
private EditText editTextBirth;
private EditText editTextAge;
private EditText editTextComp;
private SimpleDateFormat dateFormat;
private Calendar c = Calendar.getInstance();
private Calendar now = Calendar.getInstance();
private Button buttonCalc;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_add_patient);
editTextName = (EditText) findViewById(R.id.editTextName);
editTextAge = (EditText) findViewById(R.id.editTextAge);
editTextBirth = (EditText) findViewById(R.id.editTextBirth);
editTextComp = (EditText) findViewById(R.id.editTextComp);
buttonCalc = (Button) findViewById(R.id.buttonCalc);
buttonCalc.setOnClickListener(this);
dateFormat = new SimpleDateFormat("dd/MM/yyyy");
}
@Override
public void onClick(View view) {
//if calc button is pressed
if (view.getId() == R.id.buttonCalc) {
String date = editTextBirth.getText().toString();
try {
c.setTime(dateFormat.parse(date));
int age = now.get(Calendar.YEAR) - c.get(Calendar.YEAR);
if (now.get(Calendar.DAY_OF_YEAR) < c.get(Calendar.DAY_OF_YEAR)) {
age--;
}
String idade = Integer.toString(age);
editTextAge.setText(idade);
} catch (ParseException e) {
e.printStackTrace();
}
}
}
}