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in Technique[技术] by (71.8m points)

android - CheckBox[] with onClickListener[]?

EDIT: this question is mostly closed and the only problems i have with this code are discussed here

For part of my app, I have a page of items that are represented as checkboxes, each with a associated boolean that eventually get collected and stored as a string as follows:

final CheckBox gas_oil = (CheckBox) findViewById(R.id.gas_oil);
gas_oil.setOnClickListener(new OnClickListener()
{
public void onClick(View v)
    {
    if (gas_oil.isChecked())
        {
        impacts.append(getString(R.string.gas_oil) + " | ");
        anythingchecked = true;
        }
    }
});

this is extremely tedious and did not seem to be a very efficent way to do this since i have 9 or 10 items that users can check or not. also this method means that if they click and unclick something, that item is still in the StringBuilder impacts and that if they click it again then it is in there twice.

My solution was to have everything in arrays:

  String[] impactsn = getResources().getStringArray(R.array.impacts);
  final boolean[] impactsb = new boolean[impactsn.length];
  final CheckBox[] impactsc = new CheckBox[impactsn.length];
  View[] impactsv = new View[]{findViewById(R.id.gas_oil),findViewById(R.id.ghost_fishing),findViewById(R.id.marsh_damage),findViewById(R.id.nav_haz),findViewById(R.id.shell_damage),findViewById(R.id.waste_pollution),findViewById(R.id.wild_entang),findViewById(R.id.other)};

  for (int i = 0; i < impactsn.length; i++)
    {
    impactsc[i] = (CheckBox) impactsv[i];
    impactsc[i].setOnClickListener(new OnClickListener()
            {   
            @Override
            public void onClick(View v)
                {
                if (impactsc[i].isChecked())
                    impactsb[i] = true;
                else
                    impactsb[i] = false;
                }
            });
    }

unfortunately doing this causes the problem that (as far as i understand it) things within an OnClickListener have to be final. With the code as written, i can never be final, so I'm sort of at a standstill.

Should/can I have an array of OnClickListeners as well? Should I be calling to a method outside of the code I have here?

Also, below is the getter i was planning on using, I think that part will work just fine:

String getImpacts ()
    {
            String[] impactsn = getResources().getStringArray(R.array.impacts);
    StringBuilder impactss = new StringBuilder();
    for (int i = 0; i < impactsn.length; i ++)
        {
        if (impactsb[i])
                    impactss.append(impactsn[i] + " | ");
        }
    return String.valueOf(impactss);
    }

EDIT: this is the version of code im running with now:

package com.citsci.mardeb;

import android.app.Activity; import android.content.res.Resources; import android.os.Bundle; import android.view.View; import android.widget.CheckBox; import android.widget.EditText;

public class Impacts extends Activity implements View.OnClickListener { int length = 7; boolean[] impactsb = new boolean[] {false, false, false, false, false, false, false, false}; EditText view;

public void onCreate (Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.impacts);

// for (int i = 0; i < length; i++) // impactsb[i] = false;

  View[] impactsv = new View[]
     {
    findViewById(R.id.gas_oil),
        findViewById(R.id.ghost_fishing),
        findViewById(R.id.marsh_damage),
        findViewById(R.id.nav_haz),
        findViewById(R.id.shell_damage),
        findViewById(R.id.waste_pollution),
        findViewById(R.id.wild_entang),
        findViewById(R.id.other)
        };

  CheckBox[] impactsc = new CheckBox[length];

  for (int i = 0; i < length; i++)
     {
     impactsc[i] = (CheckBox) impactsv[i];
     impactsc[i].setOnClickListener(this);
     }

}// end of onCreate

@Override
public void onClick(View v)
    {
  switch (v.getId()) {
     case (R.id.gas_oil):
        impactsb[0] =! impactsb[0];
        break;
     case (R.id.ghost_fishing):
        impactsb[1] =! impactsb[1];
        break;
     case (R.id.marsh_damage):
        impactsb[2] =! impactsb[2];
        break;
     case (R.id.nav_haz):
        impactsb[3] =! impactsb[3];
        break;
     case (R.id.shell_damage):
        impactsb[4] =! impactsb[4];
        break;
     case (R.id.waste_pollution):
        impactsb[5] =! impactsb[5];
        break;
     case (R.id.wild_entang):
        impactsb[6] =! impactsb[6];
        break;
     case (R.id.other):
        impactsb[7] =! impactsb[7];
        }
    }

String getImpacts ()
    {
    String[] impactsn = new String[length];
    Resources myResources = getResources();
    impactsn = myResources.getStringArray(R.array.impacts);
  StringBuilder impactss = new StringBuilder();
    for (int i = 0; i < length; i ++)
        {
        if (impactsb[i])
            impactss.append(impactsn[i] + " | ");
        }
    if (String.valueOf(impactss) != "")
        impactss.insert(0, "Impacts: ");
    return String.valueOf(impactss);
    }
}// end of Impacts.class
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1 Answer

0 votes
by (71.8m points)

Don't use anonymous (inline) listeners in this case. Instead have your Activity implement the listener...

public class MyActivity extends Activity
    implements View.OnClickListener {

    ...

    @Override
    public void onClick(View v) {

        switch (v.getId()) {
            case impactsv[0].getId:
                impactsb[0] = !impactsb[0];
                ...
                break;

            // Add other cases here

        }

    }
}

Then all you need to do to set the listener is...

impactsc[i].setOnClickListener(this);

Then test for which CheckBox has been clicked by using the View which is passed to...

onClick(View v)


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