android - 测试字段是否为空并阻止用户保存到 sqlite - android

Question

我如何测试该字段是否由用户填写？我想提示他们必须完全填写字段。但是即使名称为空并且输入了数字，此代码仍然接受。

public void onClick(View arg0)
{
    switch(arg0.getId())
    {
    case R.id.bSQLUpdate:
        boolean diditwork = true;
        try
        {
        String name = sqlName.getText().toString();
        String number = sqlNumber.getText().toString();

        GroupDb entry = new GroupDb(ContactDb.this);
        entry.open();
        if(name != null && number != null)
        {
            if((!entry.hasDuplicateNameNumber(name, number)) )
            {
                entry.createEntry(name, number);

            }
            else
            {
                diditwork = false;
                Dialog d = new Dialog(this);
                d.setTitle("Error");
                TextView tv = new TextView(this);
                tv.setText("Duplicate name or number. Please try again.");
                d.setContentView(tv);
                d.show();
                sqlName.setText("");
                sqlNumber.setText("");
            }
        }
        else
        {
            diditwork = false;
            Dialog d = new Dialog(this);
            d.setTitle("Error");
            TextView tv = new TextView(this);
            tv.setText("Please fill up all fields. Please try again.");
            d.setContentView(tv);
            d.show();
            sqlName.setText("");
            sqlNumber.setText("");
        }

        entry.close();
        }
        catch(Exception e)
        {
            diditwork = false;
            String error = e.toString();
            Dialog d = new Dialog(this);
            d.setTitle("Update failed");
            TextView tv = new TextView(this);
            tv.setText(error);
            d.setContentView(tv);
            d.show();
            sqlName.setText("");
            sqlNumber.setText("");
        }
        finally
        {
            if(diditwork)
            {
                Dialog d = new Dialog(this);
                d.setTitle("Contact list updated");
                TextView tv = new TextView(this);
                tv.setText("Success");
                d.setContentView(tv);
                d.show();
                sqlName.setText("");
                sqlNumber.setText("");
            }
        }
        break;

    case R.id.bSQLOpenView:
        Intent intent = new Intent();
        intent.setClass(ContactDb.this, CustomListView.class);

        startActivityForResult(intent, 0);
        break;

    }

}// end onclick

Answer 1

尝试检查以下条件

if((name.length() > 0) && (number .length() > 0))
        {
// do the work

}

代替

if(name != null && number != null)
        {
// do the work
}