setdropdownviewresource标识符

Question

尝试在android中创建一个微调器：

package com.example.test; 
import android.app.Activity;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.BaseAdapter;

public class SpinnerBuilding extends Activity {
Spinner spinner = (Spinner) findViewById(R.id.building);

// Create an ArrayAdapter using the string array and a default spinner layout
ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this,
        R.array.buildings_array, android.R.layout.simple_spinner_item);

// Specify the layout to use when the list of choices appears
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

// Apply the adapter to the spinner
spinner.setAdapter(adapter);
}

package com.example.test; import android.app.Activity; import android.widget.ArrayAdapter; import android.widget.Spinner; import android.widget.BaseAdapter; public class SpinnerBuilding extends Activity { Spinner spinner = (Spinner) findViewById(R.id.building); // Create an ArrayAdapter using the string array and a default spinner layout ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this, R.array.buildings_array, android.R.layout.simple_spinner_item); // Specify the layout to use when the list of choices appears adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); // Apply the adapter to the spinner spinner.setAdapter(adapter); }

它会引发错误此外，"Syntax error on token "setDropDownViewResource", identifier expected after this token.也不起作用。

有人可以帮我解决这个问题吗？

Answer 1

你需要在一些方法中移动整个代码，你不能在类的方法之外执行代码。

最好将整个代码移到Oncreate中。

public class SpinnerBuilding extends Activity {
public void onCreate(Bundle b){

super.onCreate(b);
setContentView(R.id.layout);
Spinner spinner = (Spinner) findViewById(R.id.building);

// Create an ArrayAdapter using the string array and a default spinner layout
ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this,
        R.array.buildings_array, android.R.layout.simple_spinner_item);

// Specify the layout to use when the list of choices appears
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

// Apply the adapter to the spinner
spinner.setAdapter(adapter);
}
}

Answer 2

你不能在班上的某个地方做到这一点。我建议将几乎所有内容放入onCreate（）方法

Answer 3

您应该在Oncreate（）中设置适配器。并且还使用setContentView（R.layout.yourlayout）。