Android :-Switch button in RecyclerView. 适配器 OnCheckChangeListener

Question

1)我在 Recycler View Adapter 中使用 Switch 按钮。

2)问题是“上下文”，我想在选中或取消选中切换按钮时显示 toast 。

3) 我应该在 Toast 中使用哪个 Context 来显示 toast。

我想在切换 OnCheckChangeListener 时显示 toast

public class ChannelPartenerMyBuddiesAdapter extends RecyclerView.Adapter<ChannelPartenerMyBuddiesAdapter.MyViewHolder> {


    // String ChannelPartenerURL = Ipaddress.ChannelPartener();
    String Ip = Ipaddress.ipaddress();
    String ChannelPartenerURL = Ip + "ChannelPartener.php/";
    String TAG = Utils.LogcatTag;

    String CBId, CBActive;
    ChannelPartenerMyBuddies channelPartenerMyBuddies = new ChannelPartenerMyBuddies();
    private List<ChannelPartenerMyBuddiesItom> channelPartenerMyBuddiesItomsList;
    private ChannelPartenerMyBuddiesAdapter thisAdapter = this;
    View view;

    Context context;
    Activity activity;


    public class MyViewHolder extends RecyclerView.ViewHolder {
        public TextView inputMyCashBuddyID, inputMyCashBuddyName, inputMyCashBuddyMobile, inputMyCashBuddyLocation;
        ImageView inputCashBudyprofilPic;
        Button buttonEdit, buttonDelete;
        Switch mySwitch;

        public MyViewHolder(View view) {
            super(view);
            inputMyCashBuddyID = (TextView) view.findViewById(R.id.mtextMyBuddiesID);
            inputMyCashBuddyName = (TextView) view.findViewById(R.id.mtextMyBuddiesName);
            inputMyCashBuddyMobile = (TextView) view.findViewById(R.id.mtextMyBuddiesMobile);
            inputMyCashBuddyLocation = (TextView) view.findViewById(R.id.mtextMyBuddiesAddress);
            buttonDelete = (Button) view.findViewById(R.id.mbtnMyBuddiesDelete);

            buttonEdit = (Button) view.findViewById(R.id.mbtnMyBuddiesEdit);
            mySwitch = (Switch) view.findViewById(R.id.switch1);

            inputCashBudyprofilPic = (ImageView) view.findViewById(R.id.mCashBuddyProfile);
        }

    }

    public ChannelPartenerMyBuddiesAdapter(List<ChannelPartenerMyBuddiesItom> channelPartenerMyBuddiesItomsList) {
        this.channelPartenerMyBuddiesItomsList = channelPartenerMyBuddiesItomsList;
    }

    @Override
    public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View itemView = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.channel_partener_my_buddies_itom_list, parent, false);

        return new MyViewHolder(itemView);
    }


    @Override
    public void onBindViewHolder(final ChannelPartenerMyBuddiesAdapter.MyViewHolder holder, final int position) {

        final ChannelPartenerMyBuddiesItom channelPartenerMyBuddiesItom = channelPartenerMyBuddiesItomsList.get(position);


        holder.inputMyCashBuddyID.setText(channelPartenerMyBuddiesItom.getMyBuddiesID());
        holder.inputMyCashBuddyName.setText(channelPartenerMyBuddiesItom.getMyBuddiesName());
        holder.inputMyCashBuddyMobile.setText(channelPartenerMyBuddiesItom.getMyBiddiesMobile());
        holder.inputMyCashBuddyLocation.setText(channelPartenerMyBuddiesItom.getMyBuddiesAdress());

        new ImageLoadTask(channelPartenerMyBuddiesItom.getMyBuddiesProfilePic(), holder.inputCashBudyprofilPic).execute();


        String CBstatus = channelPartenerMyBuddiesItom.getMyBuddiesActive();
        if (CBstatus.equals("y")) {
            holder.mySwitch.setChecked(true);
            holder.mySwitch.setText("Active");
        } else {
            holder.mySwitch.setChecked(false);
            holder.mySwitch.setText("DActive");
        }


        holder.mySwitch.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton compoundButton, boolean bChecked) {
                if (bChecked) {
                    Toast.makeText(context, "Checked", Toast.LENGTH_SHORT).show();
                } else {
                    Toast.makeText(context, "Unchecked", Toast.LENGTH_SHORT).show();

                     }


            }


        });




    }

    @Override
    public int getItemCount() {
        return channelPartenerMyBuddiesItomsList.size();
    }

    public void CashBuddyActive(final Context context) {

        Log.e(TAG, ChannelPartenerURL);
        final ProgressDialog pDialog = new ProgressDialog(context);
        pDialog.setMessage("Updating Cash Buddy ...");
        pDialog.show();

        StringRequest stringRequest = new StringRequest(Request.Method.POST,
                ChannelPartenerURL,
                new Response.Listener<String>() {

                    @Override
                    public void onResponse(String response) {
                        pDialog.hide();

                        Log.e("Update responce", response);
                        try {

                            JSONObject jsonObject = new JSONObject(response);
                            String Result = jsonObject.getString("code");
                            Log.e("Upadate Cash Buddy Code", Result);
                            if (Result.equals("1")) {
                                Log.e(TAG, "Active Code 1");

                                Intent i = new Intent(thisAdapter.context, ChannelPartenerMyBuddies.class);
                                context.startActivity(i);
                                ((Activity) context).finish();


                            } else {
                                Toast.makeText(context, "Status not Changed", Toast.LENGTH_SHORT).show();
                            }


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

                    }
                }, new Response.ErrorListener() {

            @Override
            public void onErrorResponse(VolleyError error) {
                Log.e(TAG, error.getMessage());
                pDialog.hide();

            }
        }) {

            @Override
            protected Map<String, String> getParams() {
                Map<String, String> params = new HashMap<String, String>();
                params.put("getdata", "updateCashBuddyActiveDeactive");
                params.put("insert_CB_ID", CBId);
                params.put("insert_CB_status", CBActive);
                return params;
            }


        };

        //Adding request to request queue
        VolleyAppController.getInstance().addToRequestQueue(stringRequest);

    }

    public void DeleateCashBuddyStatus(final Context context, final String CashBuddyI) {

        Log.e(TAG, ChannelPartenerURL);
        Log.e("Deleat ID", CashBuddyI);
        final ProgressDialog pDialog = new ProgressDialog(context);
        pDialog.setMessage("Updating Cash Buddy ...");
        pDialog.show();

        StringRequest stringRequest = new StringRequest(Request.Method.POST,
                ChannelPartenerURL,
                new Response.Listener<String>() {

                    @Override
                    public void onResponse(String response) {
                        pDialog.hide();

                        Log.e("Update responce", response);
                        try {

                            JSONObject jsonObject = new JSONObject(response);
                            String Result = jsonObject.getString("code");
                            Log.e("Cash Buddy Code", Result);
                            if (Result.equals("1")) {
                                Intent i = new Intent(thisAdapter.context, ChannelPartenerMyBuddies.class);
                                context.startActivity(i);
                                ((Activity) context).finish();


                            } else {
                                Toast.makeText(context, "Cash Buddy no Deleated", Toast.LENGTH_SHORT).show();
                            }


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

                    }
                }, new Response.ErrorListener() {

            @Override
            public void onErrorResponse(VolleyError error) {
                Log.e(TAG, error.getMessage());
                pDialog.hide();

            }
        }) {

            @Override
            protected Map<String, String> getParams() {
                Map<String, String> params = new HashMap<String, String>();
                params.put("getdata", "deleatCashBuddy");
                params.put("insert_CB_ID", CashBuddyI);
                return params;
            }


        };

        //Adding request to request queue
        VolleyAppController.getInstance().addToRequestQueue(stringRequest);

    }

}

我在 Logcat 中遇到错误

Process: com.jmtechnologies.askuscash, PID: 7741
01-23 15:19:15.188 7741-7741/com.jmtechnologies.askuscash E/AndroidRuntime: java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.Resources android.content.Context.getResources()' on a null object reference
01-23 15:19:15.188 7741-7741/com.jmtechnologies.askuscash E/AndroidRuntime:     at android.widget.Toast.<init>(Toast.java:106)
01-23 15:19:15.188 7741-7741/com.jmtechnologies.askuscash E/AndroidRuntime:     at android.widget.Toast.makeText(Toast.java:263)
01-23 15:19:15.188 7741-7741/com.jmtechnologies.askuscash E/AndroidRuntime:     at com.jmtechnologies.askuscash.ChannelPartener.ChannelPartenerMyBuddiesAdapter$1.onCheckedChanged(ChannelPartenerMyBuddiesAdapter.java:141)
01-23 15:19:15.188 7741-7741/com.jmtechnologies.askuscash E/AndroidRuntime:     at android.widget.CompoundButton.setChecked(CompoundButton.java:154)
01-23 15:19:15.188 7741-7741/com.jmtechnologies.askuscash E/AndroidRuntime:     at android.widget.Switch.setChecked(Switch.java:862)
01-23 15:19:15.188 7741-7741/com.jmtechnologies.askuscash E/AndroidRuntime:     at android.widget.Switch.toggle(Switch.java:857)
01-23 15:19:15.188 7741-7741/com.jmtechnologies.askuscash E/AndroidRuntime:     at android.widget.CompoundButton.performClick(CompoundButton.java:118)
01-23 15:19:15.188 7741-7741/com.jmtechnologies.askuscash E/AndroidRuntime:     at android.view.View$PerformClick.run(View.java:20262)
01-23 15:19:15.188 7741-7741/com.jmtechnologies.askuscash E/AndroidRuntime:     at android.os.Handler.handleCallback(Handler.java:815)
01-23 15:19:15.188 7741-7741/com.jmtechnologies.askuscash E/AndroidRuntime:     at android.os.Handler.dispatchMessage(Handler.java:104)
01-23 15:19:15.188 7741-7741/com.jmtechnologies.askuscash E/AndroidRuntime:     at android.os.Looper.loop(Looper.java:194)
01-23 15:19:15.188 7741-7741/com.jmtechnologies.askuscash E/AndroidRuntime:     at android.app.ActivityThread.main(ActivityThread.java:5622)
01-23 15:19:15.188 7741-7741/com.jmtechnologies.askuscash E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Native Method)
01-23 15:19:15.188 7741-7741/com.jmtechnologies.askuscash E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Method.java:372)
01-23 15:19:15.188 7741-7741/com.jmtechnologies.askuscash E/AndroidRuntime:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:959)
01-23 15:19:15.188 7741-7741/com.jmtechnologies.askuscash E/AndroidRuntime:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:754)

Answer 1

你假设从调用 ChannelPartenerMyBuddiesAdapter 的地方传递上下文，假设你从 MainActivity 调用这个类，然后在 MainActivity 中写下面的代码

ChannelPartenerMyBuddiesAdapter channelPartenerMyBuddiesAdapter = new ChannelPartenerMyBuddiesAdapter(objectofList<ChannelPartenerMyBuddiesItom>,MainActivity.this);

然后在您的 ChannelPartenerMyBuddiesAdapter 类中进行如下更改

public ChannelPartenerMyBuddiesAdapter(List<ChannelPartenerMyBuddiesItom> channelPartenerMyBuddiesItomsList,Context context) {
    this.channelPartenerMyBuddiesItomsList = channelPartenerMyBuddiesItomsList;
    this.context=context
}