Question

我正在尝试根据微调器中选择的项目设置textView的文本。但它始终显示else语句的值。有人可以帮我解决这个问题。代码如下。

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.SpinnerAdapter;
import android.widget.TextView;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        String[] names = {"Shashank","Abhijay"};
        String[] state_array = {"Select City","Bangalore","Jaipur"};
        setContentView(R.layout.activity_main);
        Spinner spinner_state = (Spinner)findViewById(R.id.spinner1);
        spinner_state.setAdapter((SpinnerAdapter) new ArrayAdapter<String>(this,
                    android.R.layout.simple_list_item_1,
                    state_array ));

        if(spinner_state.equals(state_array[1]))
        {
        TextView candi_name = (TextView) findViewById(R.id.CandidateName);
        candi_name.setText(names[0]);
        }
        if(spinner_state.equals(state_array[2])){
            TextView candi_name = (TextView) findViewById(R.id.CandidateName);
            candi_name.setText(names[1]);
        }
        else{
            TextView candi_name = (TextView) findViewById(R.id.CandidateName);
            candi_name.setText(" ");
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

}

Answer 1

使用onItemSelectedListener

spinner_state.setOnItemSelectedListener(new OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parentView, View selectedItemView, int position, long id) {
    // your code here
}

@Override
public void onNothingSelected(AdapterView<?> parentView) {
    // your code here
}

});

Answer 2

如果条件为：

，请更换您的微调器

 // your code above...
if(spinner_state.getSelectedItem().toString().equals(state_array[1]))
    {
    TextView candi_name = (TextView) findViewById(R.id.CandidateName);
    candi_name.setText(names[0]);
    }
    if(spinner_state.getSelectedItem().toString().equals(state_array[2])){
        TextView candi_name = (TextView) findViewById(R.id.CandidateName);
        candi_name.setText(names[1]);
    }
    else{
        TextView candi_name = (TextView) findViewById(R.id.CandidateName);
        candi_name.setText(" ");
    }
 //your code below

Answer 3

您需要使用onItemSelectedListener（）来捕获选定的微调器项。在微调器初始化之后添加以下代码并删除if / else语句：

spinner_state.setOnItemSelectedListener(new OnItemSelectedListener() { 

    @Override 
    public void onItemSelected(AdapterView<?> parentView, View selectedItemView, int position, long id) {
        if(spinner_state.getSelectedItem().toString().equals(state_array[1]))
        {
            TextView candi_name = (TextView) findViewById(R.id.CandidateName);
            candi_name.setText(names[0]);
        }
        if(spinner_state.getSelectedItem().toString().equals(state_array[2]))
        {
            TextView candi_name = (TextView) findViewById(R.id.CandidateName);
            candi_name.setText(names[1]);
        } 
    }


    @Override 
    public void onNothingSelected(AdapterView<?> parentView) {
        TextView candi_name = (TextView) findViewById(R.id.CandidateName);
                candi_name.setText(" "); }

        });

始终在Spinner中选择Else语句

3 个答案: