Question

我在Android中使用相当简单的布局时遇到了问题。基本上，我有一个微调器，包含sqlite数据库中的几个项目。我还有一些EditText字段，用于接收和显示所选项目的信息。我现在要做的是实现一个允许用户添加新条目并更改其数据的按钮 - 所有这些都在同一个视图中（EditText字段已经编程完成）。这是我的代码（我尝试做的是使用新项目中的默认数据更新数据库并重新绘制类，但我无法将微调器设置为新位置）。你们对我如何做到这一点有什么想法吗？

public class Activity_MaterialTab extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_materialtab);

//Opens database
final SQLiteDatabase Estrutura = openOrCreateDatabase("Estutura.db", Context.MODE_PRIVATE, null);
final Cursor cursor = Estrutura.rawQuery("SELECT * FROM MATERIAIS ORDER BY [_id] ASC", null);
final Spinner spnMaterial = (Spinner) findViewById(R.id.mat_spn_material);
final EditText dVol = (EditText) findViewById(R.id.mat_frm_densidade);
final EditText modE = (EditText) findViewById(R.id.mat_frm_elasticidade);
final EditText nome = (EditText) findViewById(R.id.mat_frm_nome);
final ImageButton addMaterial = (ImageButton) findViewById(R.id.mat_btm_add);
final ImageButton excMaterial = (ImageButton) findViewById(R.id.mat_btm_exc);
final Bundle sis = savedInstanceState;

//Spinner
String from[] = {"_id","nome","modE","dVol"};
int to[] = {R.id.txvid,R.id.txvnome,R.id.txvmodE,R.id.txvdVol};
SimpleCursorAdapter ad = new SimpleCursorAdapter(getBaseContext(), R.layout.sp_material, cursor, from, to, 0);
spnMaterial.setAdapter(ad);

try {
    spnMaterial.setSelection(sis.getInt("pos"));
} catch (Exception e) {}

//Updates Edittext fields
modE.setText(String.valueOf(cursor.getDouble(2)));
dVol.setText(String.valueOf(cursor.getDouble(3)));

spnMaterial.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
    @Override
    public void onItemSelected(AdapterView<?> parent, View view,int position, long id) {
        Cursor cursor2 = Estrutura.rawQuery("SELECT * FROM MATERIAIS ORDER BY [_id] ASC", null);
        cursor2.moveToPosition(cursor.getPosition());
        nome.setText(String.valueOf(cursor2.getDouble(1)));
        modE.setText(String.valueOf(cursor2.getDouble(2)));
        dVol.setText(String.valueOf(cursor2.getDouble(3)));
        cursor.moveToPosition(position);
    }
    @Override
    public void onNothingSelected(AdapterView<?> parent) {
    }
});

modE.addTextChangedListener(new TextWatcher()
{
    @Override
    public void beforeTextChanged(CharSequence s, int start, int count,int after) {}
    @Override
    public void onTextChanged(CharSequence s, int start, int before,int count) {}

    @Override
    public void afterTextChanged(Editable s) {
        if (modE.length() != 0) { 
        String sql = "UPDATE MATERIAIS SET modE="+modE.getText().toString()+" WHERE [_id]="+String.valueOf(cursor.getInt(0));
        Estrutura.execSQL(sql);
        }
    }
});

dVol.addTextChangedListener(new TextWatcher()
{
    @Override
    public void beforeTextChanged(CharSequence s, int start, int count,int after) {}
    @Override
    public void onTextChanged(CharSequence s, int start, int before,int count) {}

    @Override
    public void afterTextChanged(Editable s) {
        if (dVol.length() != 0) { 
        String sql = "UPDATE MATERIAIS SET dVol="+dVol.getText().toString()+" WHERE [_id]="+String.valueOf(cursor.getInt(0));
        Estrutura.execSQL(sql);
        }
    }
});

addMaterial.setOnClickListener(new OnClickListener()
    {
        @Override
        public void onClick(View v) {
            String sql = "INSERT INTO MATERIAIS(nome,modE,dVol) VALUES('Nome',0,0)";
            Estrutura.execSQL(sql);
            sis.putInt("pos", cursor.getPosition());
            onCreate(sis);
            spnMaterial.setSelection(3);
        }

    });
}

}

在视图中更新微调器并更改其选定的项目

0 个答案: