Question

我正在使用SQLite数据库来存储和检索我的Android应用程序的数据。在下面的代码中，我使用toast消息将表数据恢复到了我的屏幕。我想在textview中显示所有记录到我的屏幕。我无知在哪里做了改变。如果有人可以帮我解决这个问题，那将会非常有帮助。尝试了多个选项并失败了。

这是我的主要活动。

public class MainActivity extends Activity {
protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        DatabaseHandler db = new DatabaseHandler(this);

             try {
        String destPath = "/data/data/" + getPackageName()
                + "/databases/questions";
        File f = new File(destPath);
        if (!f.exists()) {
            CopyDB(getBaseContext().getAssets().open("questions"),
                    new FileOutputStream(destPath));
        }
    } 

             catch (FileNotFoundException e) {
        e.printStackTrace();
        Toast.makeText(MainActivity.this, "Error File", Toast.LENGTH_SHORT)
                .show(); 
    } 
             catch (IOException e1) {
        e1.printStackTrace();
       Toast.makeText(MainActivity.this, "Error IO", Toast.LENGTH_SHORT)
                .show();
    }

 Cursor cursor = db.getAllQuestions();
        if (cursor.moveToFirst())
        {
            do {
                DisplayRecord(cursor);

            }
            while(cursor.moveToNext());
        }

        db.close();
    }

        public void CopyDB(InputStream inputstream, OutputStream outputstream)        
                throws IOException {
            byte[] buffer = new byte[1024];
            int length;
            while ((length = inputstream.read(buffer))>0){
                outputstream.write(buffer, 0, length);
            }
            inputstream.close();
            outputstream.close();
        }

        public void DisplayRecord(Cursor cursor){
            Toast.makeText(this,
                    "id:" + cursor.getString(0) + "\n" +
                    "Question:" + cursor.getString(1) + "\n" +
                    "Answer:" + cursor.getString(2),
                    Toast.LENGTH_SHORT).show();


        }
}

提前致谢

Answer 1

在TextView中创建与textid类似的activity_main.xml名称，然后在DisplayRecord中将Toast更改为TextView

IN activity_main.xml

<TextView
            android:id="@+id/textid"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"/>

IN MainActivity

public void DisplayRecord(Cursor cursor){

    TextView text=(TextView)findViewById(R.id.textid);
    text.setText(
        "id:" + cursor.getString(0) + "\n" +
        "Question:" + cursor.getString(1) + "\n" +
        "Answer:" + cursor.getString(2)
        );
}

在文本视图中显示Toast消息

1 个答案: