onCheckedChanged called automatically

问题

I have a switch in a recyclerview and data is displayed in the recyclerview after retrieving data from DB. When the recyclerview is opened I read DB and if a field in DB is "Y" I enable the switch or else I disable the switch. Now the problem is along with it the onCheckedchanged listener is also called, I want the onCheckedChanged to be called only when user sets the switch manually.

On opening the recyclerview below is executed:

holder.enabledisable.setChecked(messengerRecord.get_is_valid().equalsIgnoreCase("Y"));

ViewHolder class:

public class viewHolder extends RecyclerView.ViewHolder implements CompoundButton.OnCheckedChangeListener{
public SwitchCompat enabledisable;
 public viewHolder(View v) {
            enabledisable = (SwitchCompat) v.findViewById(R.id.enabledisable);
            enabledisable.setOnCheckedChangeListener(this);
...................................
...................................

OncheckedChanged method which is called when the recyclerView is just opened:

@Override
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            Log.v("ranjith","called oncheckedchanged");
            MessengerRecord rec;
            rec = dbHelper.getRecord(descview.getText().toString());
            switch (buttonView.getId()) {
                case R.id.enabledisable:
                    if (isChecked) {
                        rec.set_is_valid("Y");
                        dbHelper.updateRecord(rec);
                     }
}

In Layout file:

<android.support.v7.widget.SwitchCompat
    android:layout_marginRight="16dp"
    android:layout_marginEnd="16dp"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:focusable="false"
    android:id="@+id/enabledisable"
    android:layout_alignRight="@+id/textview_to"
    android:layout_alignEnd="@+id/textview_to"
    android:layout_alignParentRight="true"
    android:layout_alignParentEnd="true"/>

回答1:

It's weird all of us have this problem but not official Google answer to this simple problem.

The MOST simple it's to check:

buttonView.isPressed()

If true, means the user clicked the view.

No global variables needed.

Hope this helps.

回答2:

I've ended up using this subclass of SwitchCompat to avoid this issue. This way I don't need boilerplate code where I'm using this class. Whenever you need to change the checked without firing the listener, use setCheckedSilent instead of setChecked:

import android.content.Context;
import android.os.Parcelable;
import android.support.v7.widget.SwitchCompat;
import android.util.AttributeSet;

/**
 * Created by emanuel on 30/5/16.
 */
public class Switch extends SwitchCompat {

    private OnCheckedChangeListener listener;

    public Switch(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    public void setOnCheckedChangeListener(OnCheckedChangeListener listener) {
        this.listener = listener;
        super.setOnCheckedChangeListener(listener);
    }

    @Override
    public void onRestoreInstanceState(Parcelable state) {
        super.setOnCheckedChangeListener(null);
        super.onRestoreInstanceState(state);
        super.setOnCheckedChangeListener(listener);
    }

    public void setCheckedSilent(boolean checked) {
        super.setOnCheckedChangeListener(null);
        super.setChecked(checked);
        super.setOnCheckedChangeListener(listener);
    }
}

onRestoreInstanceState was triggering the listening also, when set in the onViewCreated method and you are going back to a previous fragment. Hope it works for you!

回答3:

Try this

@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {

        if (buttonView.isPressed()) {
          ... //returns true, if user clicks the switch button        
        }}

回答4:

This works for me:

 boolean selected = preferences.isChecked();
        yourCheckBox.setOnCheckedChangeListener(new 
            CompoundButton.OnCheckedChangeListener() {
                @Override
                public void onCheckedChanged(CompoundButton buttonView, 
            boolean isChecked) {
                    if (buttonView.isPressed()) {
               preferences.setChecked(isChecked);
                    } else {
                        yourCheckBox.setChecked(selected);
                    }
                }
            });

回答5:

use a global boolean variable and when read a data from DB set it "true" and after check(if) in onCheckChange set it "false" again. in first of onCheckChange method check if this variable is false execute codes else return(default value of this variable must be false ) ;

@Override
   public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
     if(!isSourceDB){ 

       Log.v("ranjith","called oncheckedchanged");
        MessengerRecord rec;
        rec = dbHelper.getRecord(descview.getText().toString());
        switch (buttonView.getId()) {
            case R.id.enabledisable:
                if (isChecked) {
                    rec.set_is_valid("Y");
                    dbHelper.updateRecord(rec);

          }
    }//end if
  isSourceDB = false; }// end oncheckedchange

回答6:

I faced the same problem inside ViewPager screen for fragments. When we switch between fragments, onCheckedChanged Listener is called again and again.

If anyone still looking for this problem, please try it.

@Override
    public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {

            if (buttonView.isInTouchMode()) {
              ... //Your code will come here.         
            }
}

来源：https://stackoverflow.com/questions/27641705/oncheckedchanged-called-automatically