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ListView刷新

2012-10-29 147 views
1

我有一个问题。我的项目中有一个sqlite数据库。我在数据库中选择数据并传输自定义列表视图。我的自定义ListView有一个删除按钮。当我按下按钮时，我的CostumListView类将删除此行。但Listview是一样的。我想在删除过程后进行刷新listview。ListView刷新

这是我的LAUNCHER类（TaskList.java）：

package com.nano.tasklist; 
import java.text.ParseException; 
import java.text.SimpleDateFormat; 
import java.util.ArrayList; 
import java.util.Date; 

import android.os.Bundle; 
import android.app.Activity; 
import android.app.AlertDialog; 
import android.content.ContentValues; 
import android.content.Context; 
import android.content.DialogInterface; 
import android.content.Intent; 
import android.database.Cursor; 
import android.database.sqlite.SQLiteDatabase; 
import android.database.sqlite.SQLiteException; 
import android.view.LayoutInflater; 
import android.view.Menu; 
import android.view.MenuItem; 
import android.view.View; 
import android.view.View.OnClickListener; 
import android.widget.Button; 
import android.widget.ListView; 
import android.widget.Toast; 

public class TaskList extends Activity { 

ArrayList<CategoryInfo> CategoryList; 

TaskListDatabase DatabaseActivity; 

private CategoryAdapter CategoryAdapter = null; 

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

    DatabaseActivity = new TaskListDatabase(this); 

    CategoryInsert("School","21.02.2012","YES"); 
    CategoryInsert("House","21.02.2012","NO"); 
    CategoryInsert("Park","21.02.2012","YES"); 

    ListView lvCategories = (ListView) findViewById(R.id.lvCategories); 

    CategoryList = new ArrayList<CategoryInfo>(); 

    CategoryAdapter = new CategoryAdapter(this, R.layout.category_row, CategoryList); 
    lvCategories.setAdapter(this.CategoryAdapter); 

    CategorySelect(); 
} 

public void CategorySelect(){ 
    String[] Column = {"ID","Category","AddDate","Completed"}; 

    Cursor Result = null; 

    try{ 
     SQLiteDatabase Database = DatabaseActivity.getReadableDatabase(); 

     Result = Database.query("Category", Column, null, null, null, null, null); 

     startManagingCursor(Result); 

     while(Result.moveToNext()){ 
      CategoryInfo Info = new CategoryInfo(); 

      CategoryList = new ArrayList<CategoryInfo>(); 

      Info.setID(Result.getString(Result.getColumnIndex("ID"))); 
      Info.setCategory(Result.getString(Result.getColumnIndex("Category"))); 
      Info.setAddDate(Result.getString(Result.getColumnIndex("AddDate"))); 
      Info.setCompleted(Result.getString(Result.getColumnIndex("Completed"))); 

      CategoryList.add(Info); 

      if(CategoryList != null && CategoryList.size() > 0){ 
       CategoryAdapter.add(CategoryList.get(0)); 
       CategoryAdapter.notifyDataSetChanged(); 
      } 
     } 
    } catch (SQLiteException Error) { 
     Toast.makeText(getApplicationContext(), "Error (CategorySelect) : " + Error.toString(), Toast.LENGTH_LONG).show(); 

     Result = null; 
    } 
} 

public boolean CategoryInsert(String Category, String AddDate, String Completed){ 
    boolean Result; 

    try{ 
     SQLiteDatabase Database = DatabaseActivity.getWritableDatabase(); 

     ContentValues Values = new ContentValues(); 

     Values.put("Category", Category); 
     Values.put("AddDate", AddDate); 
     Values.put("Completed", Completed); 

     Database.insert("Category", null, Values); 

     Result = true; 
    } catch (SQLiteException Error) { 
     Toast.makeText(getApplicationContext(), "Error (CategoryInsert) : " + Error.toString(), Toast.LENGTH_LONG).show(); 

     Result = false; 
    } 

    return Result; 
}

这是我CustomListAdapter类（CategoryAdapter.java）

package com.nano.tasklist; 

import java.util.ArrayList; 

import android.app.AlertDialog; 
import android.content.ContentValues; 
import android.content.Context; 
import android.content.DialogInterface; 
import android.database.Cursor; 
import android.database.sqlite.SQLiteDatabase; 
import android.database.sqlite.SQLiteException; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.View.OnClickListener; 
import android.view.ViewGroup; 
import android.widget.ArrayAdapter; 
import android.widget.Button; 
import android.widget.CheckBox; 
import android.widget.CompoundButton; 
import android.widget.Toast; 
import android.widget.CompoundButton.OnCheckedChangeListener; 
import android.widget.TextView; 

public class CategoryAdapter extends ArrayAdapter<CategoryInfo>{ 

private Context ActivityContext = null; 
private ArrayList<CategoryInfo> Items = null; 

TaskListDatabase DatabaseActivity; 

public CategoryAdapter(Context Context, int textViewResourceId, ArrayList<CategoryInfo> Items){ 
    super(Context,textViewResourceId,Items); 

    this.ActivityContext = Context; 
    this.Items=Items; 

    DatabaseActivity = new TaskListDatabase(Context); 
} 

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

    if (MainView == null) { 
     LayoutInflater Layout = (LayoutInflater) ActivityContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
     MainView = Layout.inflate(R.layout.category_row, null); 
    } 

    final CategoryInfo Item = Items.get(position); 

    if (Item != null) { 

     final CheckBox cbCompleted = (CheckBox) MainView.findViewById(R.id.cbCategoryCompleted); 
     final TextView tvCategoryName = (TextView) MainView.findViewById(R.id.tvCategoryName); 
     final TextView tvAddDate = (TextView) MainView.findViewById(R.id.tvAddDate); 
     final TextView tvDataValue = (TextView) MainView.findViewById(R.id.tvDataValue); 
     final Button btnDeleteCategory = (Button) MainView.findViewById(R.id.btnDeleteCategory); 

     tvCategoryName.setText(Item.getCategory()); 
     tvAddDate.setText(Item.getAddDate()); 
     tvDataValue.setText(Item.getDataValue()); 

     if(Item.getCompleted().equals("YES")){ 
      cbCompleted.setChecked(true); 

      tvCategoryName.setEnabled(false); 
      tvAddDate.setEnabled(false); 
      tvDataValue.setEnabled(false); 
     } else { 
      cbCompleted.setChecked(false); 

      tvCategoryName.setEnabled(true); 
      tvAddDate.setEnabled(true); 
      tvDataValue.setEnabled(true); 
     } 

     cbCompleted.setOnCheckedChangeListener(new OnCheckedChangeListener(){ 
      public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) { 
       if(isChecked){ 
        CategoryUpdate(Item.getID(),"Completed","YES"); 

        tvCategoryName.setEnabled(false); 
        tvAddDate.setEnabled(false); 
        tvDataValue.setEnabled(false); 
       } else { 
        CategoryUpdate(Item.getID(),"Completed","NO"); 

        tvCategoryName.setEnabled(true); 
        tvAddDate.setEnabled(true); 
        tvDataValue.setEnabled(true); 
       } 
      } 
     }); 

     btnDeleteCategory.setOnClickListener(new OnClickListener(){ 
      public void onClick(View v) { 
       TaskList Process = new TaskList(); 
       Process.Delete(btnDeleteCategory, Item.getID()); 
      } 
     }); 
    } 

    return MainView; 
} 

public boolean CategoryUpdate(String ID, String Key, String Value){ 
    boolean Result; 

    try{ 
     SQLiteDatabase Database = DatabaseActivity.getWritableDatabase(); 

     ContentValues Values = new ContentValues(); 

     Values.put(Key, Value); 

     Database.update("Category", Values, "ID = " + ID, null); 

     Result = true; 
    } catch (SQLiteException Error) { 
     Toast.makeText(ActivityContext, "Error (CategoryUpdate) : " + Error.toString(), Toast.LENGTH_LONG).show(); 

     Result = false; 
    } 

    return Result; 
} 

public void CategoryDelete(final String ID){ 
    try{ 

     AlertDialog.Builder Builder = new AlertDialog.Builder(ActivityContext); 
     Builder.setMessage("If you delete this category, category's tasks will be deleted ! Do you want to delete this category ?") 
       .setCancelable(false) 
       .setPositiveButton("YES", 
         new DialogInterface.OnClickListener() { 
          public void onClick(DialogInterface dialog, 
            int which) { 
           SQLiteDatabase Database = DatabaseActivity.getWritableDatabase(); 

           Database.delete("Category", "ID = " + ID, null); 
          } 
         }) 
       .setNegativeButton("NO", 
         new DialogInterface.OnClickListener() { 
          public void onClick(DialogInterface dialog, 
            int which) { 
           dialog.cancel(); 
          } 
         }); 
     AlertDialog Alert = Builder.create(); 
     Alert.show(); 
    } catch (SQLiteException Error) { 
     Toast.makeText(ActivityContext, "Error (CategoryDelete) : " + Error.toString(), Toast.LENGTH_LONG).show(); 
    } 
} 

}

这是我DatabaseClass（TaskListDatabase.java）

package com.nano.tasklist; 

import android.content.Context; 
import android.database.sqlite.SQLiteDatabase; 
import android.database.sqlite.SQLiteOpenHelper; 

public class TaskListDatabase extends SQLiteOpenHelper{ 

private static final String DatabaseName = "TaskList"; 
private static final int DatabaseVersion = 1; 
private static final String Category = "Category"; 
private static final String Tasks = "Tasks"; 

private static final String CreateCategoryTable = "CREATE TABLE " + Category + " (ID INTEGER PRIMARY KEY AUTOINCREMENT, Category TEXT, AddDate TEXT, Completed TEXT);"; 
private static final String CreateTaskTable = "CREATE TABLE " + Tasks + " (ID INTEGER PRIMARY KEY AUTOINCREMENT, Category TEXT, Task TEXT, AddDate TEXT, StartDate TEXT, FinishDate TEXT, Completed TEXT);"; 

public TaskListDatabase(Context Context){ 
    super(Context,DatabaseName,null,DatabaseVersion); 
} 

@Override 
public void onCreate(SQLiteDatabase Database) { 
    Database.execSQL(CreateCategoryTable); 
    Database.execSQL(CreateTaskTable); 
} 

@Override 
public void onUpgrade(SQLiteDatabase Database, int OldVersion, int NewVersion) { 
    Database.execSQL("DROP TABLE IF EXISTS " + DatabaseName); 
    onCreate(Database); 
} 
}

这是我的项目：https://rapidshare.com/files/578334898/Task%20List.rar

请帮我...

来源

2012-10-29 Abdül Yandançakar

+0

检查这个答案：http://stackoverflow.com/a/8309715/779408 – breceivemail

回答

0

你这样做是为删除记录。

btnDeleteCategory.setOnClickListener(new OnClickListener(){ 
      public void onClick(View v) { 
       TaskList Process = new TaskList(); 
       Process.Delete(btnDeleteCategory, Item.getID()); 
      } 
     });

您的错误。

1)TaskList is your launcher Activity and I can't find any Delete() method in this class and call it in listener. 
2)May be some code of query for delete in this method Delete() 
3)You didn't refresh list using `categoryAdapter.notifyDataSetChanged();`

解决方案：

1)Make method for delete(delete query) in `TaskListDatabase.java` 
2)You display data from `ArrayList<CategoryInfo> Items;` so You also remove that data from this ArrayList. 
3)Use `categoryAdapter.notifyDataSetChanged();` for refresh list

试试这个代码...

btnDeleteCategory.setOnClickListener(new OnClickListener(){ 
      public void onClick(View v) { 
       TaskListDatabase db = new TaskListDatabase(); 
       db.delete(); 
       Items.remove(position); 
       notifyDataSetChanged(); 
      } 
     });

来源

2012-10-29 08:47:31

2

您删除该行后，调用

categoryAdapter.notifyDataSetChanged();

方法来刷新列表视图。

来源

2012-10-29 08:39:10

0 
btnDeleteCategory.setOnClickListener(new OnClickListener(){ 
     public void onClick(View v) { 
      TaskList Process = new TaskList(); 
      Process.Delete(btnDeleteCategory, Item.getID()); 
      this.CategoryAdapter.notifyDataSetChanged(); // refresh list view 
     } 
    });

来源

2012-10-29 08:39:28 Carnal

1

删除按钮：添加行： -

  adapter.notifyDataSetChanged();//or 
      list.destroyDrawingCache();//both line

来源

2012-10-29 08:41:44

+0

+ 1它工作的人。 – Jacob

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