使用android单选按钮执行方法答案

【问题标题】：Using android radio button to execute method使用android单选按钮执行方法
【发布时间】：2016-04-06 19:23:20
【问题描述】：

我有 2 个单选按钮和 1 个按钮。我希望当我单击普通按钮时，它会检查选中了哪个单选按钮并基于该按钮执行方法。以下是我使用的代码，但是当我单击按钮时应用程序崩溃

@Override
    public void onClick(View v) {

        radioGroup = (RadioGroup) v.findViewById(R.id.radioPost);
        rdpublic=(RadioButton) v.findViewById(R.id.radioPublic);
        rdprivate=(RadioButton) v.findViewById(R.id.radioPrivate);

        radioGroup.setOnCheckedChangeListener(new OnCheckedChangeListener()
        {

            public void onCheckedChanged(RadioGroup group, int checkedId)
            {

                if(rdpublic.isChecked())
                {
                    new PostPublic().execute();
                }
                else if(rdprivate.isChecked())
                {
                    new PostPrivate().execute;
                }
            }
        });

    }

【问题讨论】：

你为什么要做类似 v.findViewById() 的事情？这似乎是一个简单的按钮的 onClick 方法，对吧？
我正在使用一个片段，所以我必须把它放出来

标签： android methods radio-button

【解决方案1】：

试试这个.....

    normalBtn= (Button) findViewById(R.id.Btn);
    rdpublic=(RadioButton) findViewById(R.id.radioPublic);
    rdprivate=(RadioButton) findViewById(R.id.radioPrivate);

    normalBtn.setOnClickListener(new View.OnClickListener() {

        public void onClick(View arg0) {
            try {
      if(rdpublic.isChecked())
            {
                new PostPublic().execute();
            }
            else if(rdprivate.isChecked())
            {
                new PostPrivate().execute;
            }

            }catch(Exception e)
            {
                e.printStackTrace();
            }
        }
    });

【讨论】：

【解决方案2】：

为什么要使用按钮视图来查找 RadioButtons 和 Group？而不是 v.findViewById，您应该只使用 findViewById。

【讨论】：

+ 你在 PostPrivate().execute 中执行后缺少 ()

【解决方案3】：

您的代码假定您的Buttons 或RadioButtons 是传递的View 的子Views v。这实际上是错误的，这就是您获得 NPE 的原因。

【讨论】：

【解决方案4】：

这是完整的代码。

package com.project.bsc.radianstores;

import android.widget.RadioGroup.OnCheckedChangeListener;
import android.app.ProgressDialog;
import android.content.SharedPreferences;
import android.os.AsyncTask;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.Spinner;
import android.widget.Toast;

import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONException;
import org.json.JSONObject;

import java.util.ArrayList;
import java.util.List;

public class PostEnquiry extends Fragment implements OnClickListener {

    public String[] sItemType;
    public int position =0;

    private EditText Message;

    JSONParser jsonParser = new JSONParser();

    private ProgressDialog pDialog;

    private static final String POST_PRIVATE_URL = "http://192.168.1.102/webservice/privateenquiry.php";

    private static final String POST_PUBLIC_URL = "http://192.168.1.102/webservice/publicenquiry.php";

    private static final String TAG_SUCCESS = "success";
    private static final String TAG_MESSAGE = "message";

    private Button BtnSave;

    private RadioGroup radioGroup;
    private RadioButton rdpublic;
    private RadioButton rdprivate;

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View v = inflater.inflate(R.layout.enquiry, container, false);

        BtnSave = (Button) v.findViewById(R.id.sendEnquiry);
        Message = (EditText)v.findViewById(R.id.MessageBox);
        Spinner spItemType = (Spinner) v.findViewById(R.id.spinnerItemType);
        sItemType = getResources().getStringArray(R.array.ItemType);
        BtnSave.setOnClickListener(this);

        ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(getActivity(),android.R.layout.simple_spinner_item, sItemType);
        dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spItemType.setAdapter(dataAdapter);


        //setting up listener for the spinner
        spItemType.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
                int index = arg0.getSelectedItemPosition();
                position = index;
            }

            @Override
            public void onNothingSelected(AdapterView<?> arg0) {

            }
        });

        return v;

    }

    @Override
    public void onClick(View v) {

        radioGroup = (RadioGroup) v.findViewById(R.id.radioPost);
        rdpublic=(RadioButton) v.findViewById(R.id.radioPublic);
        rdprivate=(RadioButton) v.findViewById(R.id.radioPrivate);

        radioGroup.setOnCheckedChangeListener(new OnCheckedChangeListener()
        {
            @Override
            public void onCheckedChanged(RadioGroup group, int checkedId)
            {

                if(checkedId == rdpublic.getId()) {
                    new PostPublic().execute();
                }

                else if (checkedId == rdprivate.getId()) {
                    //new PostPrivate().execute();
                }


            }
        });

    }


    class PostPublic extends AsyncTask<String, String, String> {

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            pDialog = new ProgressDialog(getActivity());
            pDialog.setMessage("Posting Enquiry...");
            pDialog.setIndeterminate(false);
            pDialog.setCancelable(true);
            pDialog.show();
        }

        @Override
        protected String doInBackground(String... args) {
            // TODO Auto-generated method stub
            // Check for success tag
            int success;

            String strItemType = sItemType[position];;
            String strMessage = Message.getText().toString();


            SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(getActivity());
            String strUsername = sp.getString("Username", "");


            try {
                // Building Parameters
                List<NameValuePair> params = new ArrayList<NameValuePair>();
                params.add(new BasicNameValuePair("Username", strUsername));
                params.add(new BasicNameValuePair("Item_Type", strItemType));
                params.add(new BasicNameValuePair("Message", strMessage));


                Log.d("request!", "starting");

                //Posting user data to script
                JSONObject json = jsonParser.makeHttpRequest(
                        POST_PUBLIC_URL, "POST", params);

                // full json response
                Log.d("Enquiry Posting attempt", json.toString());

                // json success element
                success = json.getInt(TAG_SUCCESS);
                if (success == 1) {
                    Log.d("Enquiry Posted Successful!", json.toString());

                    return json.getString(TAG_MESSAGE);
                }else{
                    Log.d("Posting Failure!", json.getString(TAG_MESSAGE));
                    return json.getString(TAG_MESSAGE);

                }
            } catch (JSONException e) {
                e.printStackTrace();
            }

            return null;

        }

        protected void onPostExecute(String file_url) {
            // dismiss the dialog once product deleted
            pDialog.dismiss();
            if (file_url != null)
                Toast.makeText(getActivity(), file_url, Toast.LENGTH_LONG).show();

        }

    }

}

【讨论】：