java - Android:删除选定的列表项

Question

所以我有一个名为 ShowActivity.java 的类。在本类(class)中，我从 sqlite 数据库获取一个列表。我在此 ListView 显示数据和删除数据上添加了两个按钮。因此，一旦我选择一个列表项，我想根据按钮单击事件执行任何一项操作(显示数据或删除所选行)。

在下面的代码中。我所做的是选择一行，一旦我单击一个行项目，我就会得到一个包含该行信息的完整 toast 。

我想做的是:一旦我选择一行，如果我点击显示数据按钮，我应该得到我现在得到的信息。或者

一旦我选择一行，如果我单击删除数据按钮，我应该从 ListView 和数据库中删除该数据。

public class ShowlistActivity extends Activity {
 String myBtnListener;
private ListView listView;
Button showBtn =findViewById(R.id.show_btn);
Button deleteBtn=findViewById(R.id.delete_btn)

@SuppressLint("NewApi")
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.showlist_ehr);

    listView = (ListView) this.findViewById(R.id.checkout_listview);
    listView.setOnItemClickListener(new ItemClickListener());

    // get the sql string delivered from the QueryActivity
    Intent intent = this.getIntent();
    String sql = intent.getStringExtra("sql");
    // execute the sql
    Cursor cursor = DBOperator.getInstance().execQuery(sql);
    // bind the data to list
    SimpleCursorAdapter adapter = new SimpleCursorAdapter(
            getApplicationContext(), R.layout.listitem_ehr, cursor,
            new String[] { "PaFirstName", "VisitDate", "MedIssue" }, new 
int[] {
            R.id.stname, R.id.coduedate, R.id.lbtitle },
            SimpleCursorAdapter.IGNORE_ITEM_VIEW_TYPE);
    listView.setAdapter(adapter);
    showBtn.setOnClickListener(myBtnListener);
    button2.setOnClickListener(myBtnListener);

    View.OnClickListener myBtnListener= new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            switch(view.getId()){
                case R.id.button1_id:
                    //do button 1 action
                    break;
                case R.id.button2_id:
                    //do button 2 action
                    break;
            }
        }
    }
}

private class ItemClickListener implements OnItemClickListener {
    public void onItemClick(AdapterView<?> parent, View view, int position,long id) {

        Cursor cursor = (Cursor) listView.getItemAtPosition(position);
        String stid = cursor.getString(0);
        String lbtitle = cursor.getString(1);
        String coduedate = cursor.getString(2);
        //String coreturned = cursor.getString(3);
        // cofine = cursor.getString(4);
        //String stname = cursor.getString(5);
        Toast.makeText(getApplicationContext(),"Student ID: " + stid + "\nStudent Name: " + lbtitle+ "\nBook Title: " + coduedate , Toast.LENGTH_LONG).show();



    }
}


}

Answer 1

向 ListView 添加选择模式。 rounded_border 是您制作的自定义可绘制对象，用作所选项目指示器。

android:choiceMode="singleChoice"
android:listSelector="@drawable/rounded_border"

更新你的onCreate

@SuppressLint("NewApi")
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.showlist_ehr);

...

...

    View.OnClickListener myBtnListener= new View.OnClickListener() {
        @Override
        public void onClick(View view) {

            if(listView.getCheckedItemPosition() >= 0) {
               //get the object
               Cursor selectedCursor = (Cursor) listView.getItemAtPosition(listView.getCheckedItemPosition());

               switch(view.getId()){
                   case R.id.show_btn:
                       //show selectedCursor details
                       break;
                   case R.id.delete_btn:
                       String stid = selectedCursor.getString(0);
                       //change the stud_id to your database field id name
                       String sql = "DELETE FROM Student WHERE stud_id = '" + stid + "'";
                       Cursor cursor = DBOperator.getInstance().execQuery(sql);
                       adapter.changeCursor(cursor);
                       break;
               }
           }
        }
    }

    showBtn.setOnClickListener(myBtnListener);
    deleteBtn.setOnClickListener(myBtnListener);
}