保留listview的每一行内的元素状态

时间:2012-04-22 15:54:29

标签: android android-listview baseadapter layout-inflater

我通过使用inflater对每一行进行充气来设计一个列表视图,并且我在其点击事件中更改了convertView元素的颜色。但滚动列表后,元素会丢失这些更改。我怎样才能“保留”他们的状态并代表他们?

在我的脑海中还有一个问题,当点击提交按钮时,如何计算未点击的“列表项目”的总数?

before scroll http://69.imagebam.com/download/l4tJZG08i5tM_7SV3K_fHQ/18631/186307764/snap1.png after scroll http://17.imagebam.com/download/CC3cRv0ITi42Fo8WWUs86g/18631/186307781/snap4.png

这是我的代码:

package scf.login;


import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.graphics.Color;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.View.OnClickListener;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

public class firstsubActivity extends Activity
{

//variable declaration
ListView lvSubCat;
Intent action;
Button btnBack,btnSubmit,btnNext;
Boolean submission=false;
Integer unchecked=0;
String[] subStatus = {"","Ok","","","","Ok","","","Alert","","","","Checked","","","Ok","","","Alert",""};

// defining on click listener
android.view.View.OnClickListener lstnr = new android.view.View.OnClickListener() 
{

    @Override
    public void onClick(View v) 
    {
    switch (v.getId()) {

    case R.id.btnBack:
            Toast.makeText(getApplicationContext(), "Back button clicked", Toast.LENGTH_SHORT).show();
        break;
    case R.id.btnSubmit:
            if(!submission)
            {

                checkcompletion();

                if(unchecked>0)
                {
                    Toast.makeText(firstsubActivity.this, "Complete the precheking of "+unchecked+" intervention(s) highlighted by Gray colour", Toast.LENGTH_LONG).show();
                }
                else
                {
                    Toast.makeText(firstsubActivity.this,"Successfully submitted !!",Toast.LENGTH_SHORT).show();                        
                    submission=true;
                }

            }
            else
            {
                updatecofirmation();
            }
        break;
    case R.id.btnNext:
            if(submission)
            {
                nextconfirmation();
            }
            else
            {
                Toast.makeText(firstsubActivity.this,"Submit the answers",Toast.LENGTH_SHORT).show();
            }
        break;

    }

}

    private void nextconfirmation() 
    {
        AlertDialog.Builder builder = new AlertDialog.Builder(firstsubActivity.this);
        builder.setCancelable(false);
        builder.setTitle("Confirmation message");
        builder.setMessage("Do you want to leave this page ?");
        builder.setPositiveButton("Yes", new DialogInterface.OnClickListener() {

            @Override
            public void onClick(DialogInterface dialog, int which) {
                // TODO Auto-generated method stub

                Intent action = new Intent(firstsubActivity.this,cat_subcatActivity.class);
                startActivity(action);      
                }
        });
        builder.setNegativeButton("No", new DialogInterface.OnClickListener() {

            @Override
            public void onClick(DialogInterface dialog, int which) {
                // TODO Auto-generated method stub
                Toast.makeText(firstsubActivity.this, "No clicked", Toast.LENGTH_SHORT).show();

            }
        });

        builder.create().show();
    }


    private void updatecofirmation() 
    {
        AlertDialog.Builder builder2 = new AlertDialog.Builder(firstsubActivity.this);
        builder2.setCancelable(false);
        builder2.setTitle("Confirmation message");
        builder2.setMessage("Do you want to update answers ?");
        builder2.setPositiveButton("Yes", new DialogInterface.OnClickListener() {

            @Override
            public void onClick(DialogInterface dialog, int which) {
                // TODO Auto-generated method stub
                submission=false;
                btnSubmit.performClick();
            }
        });
        builder2.setNegativeButton("No", new DialogInterface.OnClickListener() {

            @Override
            public void onClick(DialogInterface dialog, int which) {
                // TODO Auto-generated method stub
                Toast.makeText(firstsubActivity.this, "No clicked", Toast.LENGTH_SHORT).show();

            }
        });

        builder2.create().show();
    }


    private void checkcompletion() 
    {
        unchecked=subStatus.length;
        try
        {
            for(Integer j=0;j<subStatus.length;j++)
            {
                // CONFUSED
            }

        }


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

        }



    }


};

@Override
protected void onCreate(Bundle savedInstanceState) 
{
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.firstsub);

    //Binding
    lvSubCat = (ListView)findViewById(R.id.lvSubCat);
    btnBack = (Button)findViewById(R.id.btnBack);
    btnSubmit=(Button)findViewById(R.id.btnSubmit);
    btnNext = (Button)findViewById(R.id.btnNext);

    //setting listeners
    btnBack.setOnClickListener(lstnr);
    btnSubmit.setOnClickListener(lstnr);
    btnNext.setOnClickListener(lstnr);


    //data of subcategories and their status from database
    String[] subCat = {"zero","first","second","third","forth","fifth","sixth","seventh","eighth","ninth","tenth","eleventh","twelfth","thirteenth","forteenth","fifteenth","sixteenth","seventeenth","eighteenth","ninteenth"};
    String[] subStatus = {"","Ok","","","","Ok","","","Alert","","","","Checked","","","Ok","","","Alert",""};
    /*
    for(Integer i=0;i<subStatus.length;i++)
    {
        set the status of each subcategory
    }
    */

    //setting adapter and binding adapter to the views
    MySimpleAdapter adapter1 = new MySimpleAdapter(this,subCat);
    lvSubCat.setAdapter(adapter1);
}

//defining customised MySimpleAdapter class inside firstsubActivity class
public class MySimpleAdapter extends BaseAdapter 
{
    private final Activity context;
    private final String[] subCat;


    public MySimpleAdapter(Activity context, String[] subCat) 
    {
        super();
        this.context = context;
        this.subCat = subCat;
    }
/*      
    protected class viewHolder
    {
        TextView tvOk;
        Button btnChecked,btnAlert;
    }
*/
    @Override
    public int getCount() {
        // TODO Auto-generated method stub
        return subCat.length;
    }
    @Override
    public Object getItem(int arg0) {
        // TODO Auto-generated method stub
        return null;
    }
    @Override
    public long getItemId(int arg0) {
        // TODO Auto-generated method stub
        return 0;
    }

    @Override
    public View getView(final int position, View convertView, ViewGroup parent) 
    {

//      final viewHolder holder = new viewHolder();

        //inflating
        LayoutInflater inflater = context.getLayoutInflater();
        convertView = inflater.inflate(R.layout.lstinfl,null);


        //binding
            final TextView tvOk=(TextView)convertView.findViewById(R.id.tvOk);
            final Button btnChecked=(Button)convertView.findViewById(R.id.btnChecked);
            final Button btnAlert=(Button)convertView.findViewById(R.id.btnAlert);

        //inserting subcategories
        tvOk.setText(subCat[position]);

        //representing subcategories according to their status
        try
        {
            for(Integer k=0;k<subStatus.length;k++)
            {
                // CONFUSED

            }

        }
        catch (Exception e) {
            // TODO: handle exception
        }
        finally
        {

        }

        //listeners to change the Color and Status
        tvOk.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View arg0) {
                tvOk.setClickable(false);
                btnChecked.setClickable(true);
                btnAlert.setClickable(true);
                tvOk.setBackgroundColor(Color.GREEN);
                btnChecked.setBackgroundColor(Color.WHITE);
                btnAlert.setBackgroundColor(Color.WHITE);
                subStatus[position]="Ok";
            }
        });

        btnChecked.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                tvOk.setClickable(true);
                btnChecked.setClickable(false);
                btnAlert.setClickable(true);
                tvOk.setBackgroundColor(Color.BLACK);
                btnChecked.setBackgroundColor(Color.YELLOW);
                btnAlert.setBackgroundColor(Color.WHITE);
                subStatus[position]="Checked";
//                  action = new Intent(getApplicationContext(), subdescActivity.class);
//                  startActivity(action);

            }
        });

        btnAlert.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                tvOk.setClickable(true);
                btnChecked.setClickable(true);
                btnAlert.setClickable(false);
                tvOk.setBackgroundColor(Color.BLACK);
                btnChecked.setBackgroundColor(Color.WHITE);
                btnAlert.setBackgroundColor(Color.RED);
                subStatus[position]="Alert";
//                  action = new Intent(getApplicationContext(), subdescActivity.class);
//                  startActivity(action);
            }
        });


        return convertView;


    }   

}
}

1 个答案:

答案 0 :(得分:1)

好吧,你要在数组中保存两个状态(文本和状态),所以至少那部分是好的。现在,您需要检查getView()中的states[],根据它来设置按钮的正确外观,如:

          if (subStatus[position].equals("Ok")) {
            tvOk.setClickable(false);
            btnChecked.setClickable(true);
            btnAlert.setClickable(true);
            tvOk.setBackgroundColor(Color.GREEN);
            btnChecked.setBackgroundColor(Color.WHITE);
            btnAlert.setBackgroundColor(Color.WHITE);
            subStatus[position]="Ok";
          }
          ....

然后,当您提交时,您可以浏览这些状态项并查看点击的内容。