1

您好stackoverflow我正在尝试开发一个可以显示所有列表的应用程序，installed application下面Icon, Name & Check Box是我的代码

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >

<ListView
    android:id="@android:id/list"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content" />

</LinearLayout>

row.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >

<ImageView
    android:id="@+id/app_icon"
    android:layout_width="50dp"
    android:layout_height="50dp"
    android:padding="3dp"
    android:scaleType="centerCrop" />

<LinearLayout
    android:layout_width="wrap_content"
    android:layout_height="fill_parent"
    android:gravity="center_vertical"
    android:orientation="vertical"
    android:paddingLeft="5dp" >

    <TextView
        android:id="@+id/app_name"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:gravity="center_vertical"
        android:textStyle="bold" />

    <TextView
        android:id="@+id/app_paackage"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:gravity="center_vertical" />
</LinearLayout>

<CheckBox
    android:id="@+id/cb_app"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" />

</LinearLayout>

MainActivity.java

public class MainActivity extends ListActivity {
private PackageManager packageManager = null;
private List<ApplicationInfo> applist = null;
private ApplicationAdapter listadaptor = null;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    packageManager = getPackageManager();

    new LoadApplications().execute();
}

@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
    super.onListItemClick(l, v, position, id);

    ApplicationInfo app = applist.get(position);
    try {
        Intent intent = packageManager
                .getLaunchIntentForPackage(app.packageName);

        if (null != intent) {
            startActivity(intent);
        }
    } catch (ActivityNotFoundException e) {
        Toast.makeText(MainActivity.this, e.getMessage(),
                Toast.LENGTH_LONG).show();
    } catch (Exception e) {
        Toast.makeText(MainActivity.this, e.getMessage(),
                Toast.LENGTH_LONG).show();
    }
}

private List<ApplicationInfo> checkForLaunchIntent(List<ApplicationInfo> list) {
    ArrayList<ApplicationInfo> applist = new ArrayList<ApplicationInfo>();
    for (ApplicationInfo info : list) {
        try {
            if (null != packageManager.getLaunchIntentForPackage(info.packageName)) {
                applist.add(info);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    return applist;
}

private class LoadApplications extends AsyncTask<Void, Void, Void> {
    private ProgressDialog progress = null;

    @Override
    protected Void doInBackground(Void... params) {
        applist = checkForLaunchIntent(packageManager.getInstalledApplications(PackageManager.GET_META_DATA));
        listadaptor = new ApplicationAdapter(MainActivity.this,
                R.layout.row, applist);

        return null;
    }

    @Override
    protected void onCancelled() {
        super.onCancelled();
    }

    @Override
    protected void onPostExecute(Void result) {
        setListAdapter(listadaptor);
        progress.dismiss();
        super.onPostExecute(result);
    }

    @Override
    protected void onPreExecute() {
        progress = ProgressDialog.show(MainActivity.this, null,
                "Loading application info...");
        super.onPreExecute();
    }

    @Override
    protected void onProgressUpdate(Void... values) {
        super.onProgressUpdate(values);
    }
}
}

ApplicationAdapter.java

import java.util.List;

import android.content.Context;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageManager;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;

public class ApplicationAdapter extends ArrayAdapter<ApplicationInfo> {
private List<ApplicationInfo> appsList = null;
private Context context;
private PackageManager packageManager;

public ApplicationAdapter(Context context, int textViewResourceId,
        List<ApplicationInfo> appsList) {
    super(context, textViewResourceId, appsList);
    this.context = context;
    this.appsList = appsList;
    packageManager = context.getPackageManager();
}

@Override
public int getCount() {
    return ((null != appsList) ? appsList.size() : 0);
}

@Override
public ApplicationInfo getItem(int position) {
    return ((null != appsList) ? appsList.get(position) : null);
}

@Override
public long getItemId(int position) {
    return position;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    View view = convertView;
    if (null == view) {
        LayoutInflater layoutInflater = (LayoutInflater) context
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        view = layoutInflater.inflate(R.layout.row, null);
    }

    ApplicationInfo data = appsList.get(position);
    if (null != data) {
        TextView appName = (TextView) view.findViewById(R.id.app_name);
        TextView packageName = (TextView) view.findViewById(R.id.app_paackage);
        ImageView iconview = (ImageView) view.findViewById(R.id.app_icon);

        appName.setText(data.loadLabel(packageManager));
        packageName.setText(data.packageName);
        iconview.setImageDrawable(data.loadIcon(packageManager));
    }
    return view;
}

问题是每当我勾选 aCheck Box并滚动滚动窗口Check Box中的其他框时selected。请帮我解开这个谜。

谢谢。

4

2 回答 2

4

发生这种情况的原因是因为您的视图正在被重复使用，但您没有重置getView.

我建议你这样做：

import java.util.List;

import android.content.Context;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageManager;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;

public class ApplicationAdapter extends ArrayAdapter<ApplicationInfo> {
private List<ApplicationInfo> appsList = null;
private Context context;
private PackageManager packageManager;
private ArrayList<Boolean> checkList = new ArrayList<Boolean>();

public ApplicationAdapter(Context context, int textViewResourceId,
        List<ApplicationInfo> appsList) {
    super(context, textViewResourceId, appsList);
    this.context = context;
    this.appsList = appsList;
    packageManager = context.getPackageManager();

    for (int i = 0; i < appsList.size(); i++) {
        checkList.add(false);
    }
}

@Override
public int getCount() {
    return ((null != appsList) ? appsList.size() : 0);
}

@Override
public ApplicationInfo getItem(int position) {
    return ((null != appsList) ? appsList.get(position) : null);
}

@Override
public long getItemId(int position) {
    return position;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    View view = convertView;
    if (null == view) {
        LayoutInflater layoutInflater = (LayoutInflater) context
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        view = layoutInflater.inflate(R.layout.row, null);
    }

    ApplicationInfo data = appsList.get(position);
    if (null != data) {
        TextView appName = (TextView) view.findViewById(R.id.app_name);
        TextView packageName = (TextView) view.findViewById(R.id.app_paackage);
        ImageView iconview = (ImageView) view.findViewById(R.id.app_icon);

        CheckBox checkBox = (CheckBox) view.findViewById(R.id.cb_app);
        checkBox.setTag(Integer.valueOf(position)); // set the tag so we can identify the correct row in the listener
        checkBox.setChecked(checkList.get(position); // set the status as we stored it        
        checkBox.setOnCheckedChangeListener(mListener); // set the listener

        appName.setText(data.loadLabel(packageManager));
        packageName.setText(data.packageName);
        iconview.setImageDrawable(data.loadIcon(packageManager));
    }
    return view;
}

OnCheckedChangeListener mListener = new OnCheckedChangeListener() {

     public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {   
         checkList.set((Integer)buttonView.getTag(),isChecked); // get the tag so we know the row and store the status 
     }
};
}

基本上，有一个 arraylist 存储每个复选框的状态（对应于您的数据）。例如：当您单击位置1上的复选框时，checkList.get(1)是true.

由于视图被重用，您需要存储每个复选框相对于其位置的状态。即位置x的复选框是否被选中。然后，当您执行getView()位置操作时，x您使用存储的状态来设置正确的检查值。

更新false用值初始化 checkList 。

于 2013-10-23T05:15:59.160 回答
-1

您应该在 sqlite 中维护已经访问过的项目列表

checkBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener()
                {
                    @Override
                    public void onCheckedChanged(CompoundButton buttonView, boolean isChecked)
                    {
                        if ( isChecked )
                        {
                            // perform logic
                            checkList.set((Integer) buttonView.getTag(), isChecked); // get the tag so we know the row and store the status
                            int position = (int) buttonView.getTag();
                            Toast.makeText(context,String.valueOf(position),Toast.LENGTH_LONG).show();
                            boolean result= help.insertContact(String.valueOf(position));
                            System.out.println(result);
                        }
    
                }
            });
        if (count == 0){
            count++;
            ids = new ArrayList<String>();
            ids = help.getAllCotacts();
            if (ids.size() > 0) {
                for (int i = 0; i < ids.size(); i++) {
                    checkBox.setChecked(checkList.set(Integer.parseInt(ids.get(i)),true));
                }

                Toast.makeText(context, String.valueOf(ids.get(0)), Toast.LENGTH_LONG).show();
            } else {
                Toast.makeText(context, "No values in DB", Toast.LENGTH_LONG).show();
            }
        }
于 2016-10-21T07:57:10.050 回答