要查看数学操作的结果

Question

我想显示包含两个值的添加结果的文本：one from onepinner selected item，另一个来自twospinner selected item。但日食显示行中有错误

text.setText(onespinner.getSelectedItem + twospinner.getSelectedItem); 

怎么回事？完整的代码如下。

public class photographer extends Activity implements OnItemSelectedListener { 
/** Called when the activity is first created. */ 
@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.main); 

    Spinner onespinner = (Spinner) findViewById(R.id.spinner1); 
    ArrayAdapter<CharSequence> unitadapter = ArrayAdapter.createFromResource(
      this, R.array.onespinner, android.R.layout.simple_spinner_item); 
    unitadapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); 
    onespinner.setAdapter(unitadapter); 
    onespinner.setOnItemSelectedListener(this); 

    Spinner twospinner = (Spinner) findViewById(R.id.spinner2); 
    ArrayAdapter<CharSequence> courseadapter = ArrayAdapter.createFromResource(
      this, R.array.twospinner, android.R.layout.simple_spinner_item); 
    courseadapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); 
    twospinner.setAdapter(courseadapter); 
    twospinner.setOnItemSelectedListener(this); 



} 

@Override 
public void onItemSelected(AdapterView<?> parent, View view, int position, 
     long id) { 

    TextView text = (TextView)findViewById(R.id.result); 
    text.setText(onespinner.getSelectedItem + twospinner.getSelectedItem); 

} 

@Override 
public void onNothingSelected(AdapterView<?> parent) { 


} 
} 

Answer 1

您还没有公布确切的错误，但我猜，你的问题是，你试图在onItemSelected那些两onespinner和twospinner参考对象不在该函数的范围内;它们在onCreate中声明。

现在，onItemSelected的View view参数是被点击的微调器，但是您需要对两个微调器（而不仅仅是所选的微调器）的引用。最简单的方法是全球宣布oneSpinner和twoSpinner，这应该可以解决您的问题。

编辑：也泰德霍普说。

Answer 2

getSelectedItem是一种方法，但是您将其引用为实例变量。您需要将代码更改为：

text.setText(onespinner.getSelectedItem() + twospinner.getSelectedItem());