Question

Possible Duplicate:
Looping through editTexts to check values

I have a layout with about 100 editTexts (15 rows, 10 columns), all named based on their row / column IDs (e.g. box0101, box0102 etc.).

I have a method clearBoard() that is called when a ‘clear’ button is clicked (see code below). It is intended to loop through all of the boxes (box0101, box0102, box0103 etc.) and replace the contents with “” – making them blank.

The error that comes up in the LogCat says java.lang.NoSuchFieldException: box0101
at java.lang.Class.getDeclaredField(Class.java:631) – but there is definitely a box0101 defined in my xml and i reference it several other times during the code with no problem.

Any ideas?

From XML

           <EditText 
            android:gravity="center"
            android:layout_marginLeft="10dp"
            android:id="@+id/box0101"
            android:layout_width="30dp"
            android:layout_height="30dp"
            android:background="@drawable/boxoutlineone" />    
        <EditText 
            android:gravity="center"
            android:id="@+id/box0201"
            android:layout_width="30dp"
            android:layout_height="30dp"
            android:background="#000000" />   
        <EditText
            android:gravity="center" 
            android:id="@+id/box0301"
            android:layout_width="30dp"
            android:layout_height="30dp"
            android:background="#000000" />   
        <EditText 
            android:gravity="center"
            android:id="@+id/box0401"
            android:layout_width="30dp"
            android:layout_height="30dp"
            android:background="#000000" />

In Activity:

final EditText box0101 = (EditText)findViewById(R.id.box0101);
    final EditText box0201 = (EditText)findViewById(R.id.box0201);
    final EditText box0301 = (EditText)findViewById(R.id.box0301);
    final EditText box0401 = (EditText)findViewById(R.id.box0401);
    final EditText box0501 = (EditText)findViewById(R.id.box0501);

etc…

    public void clearBoard() {
    final int ROW_COUNT = 14;
    final int COL_COUNT = 9;
    final String ROWS[] = {"01","02","03","04","05","06","07","08","09","10","11","12","13","14","15"};
    final String COLS[] = {"01","02","03","04","05","06","07","08","09","10"};

    for(int i=0; i<ROW_COUNT; i++) {
        for(int j=0; j<COL_COUNT; j++) {
            String a = ROWS[i];
            String b = COLS[j];
            int editTextId=getResId("box"+a+b,this,id.class);
            EditText et=(EditText)findViewById(editTextId);    
            et.setText("");
        }
    }
}

public static int getResId(String variableName, Context context, Class<?> c) {

    try {
        Field idField = c.getDeclaredField(variableName);
            return idField.getInt(idField);
        } catch (Exception e) {
            e.printStackTrace();
            return -1;
        }
}

Answer 1

I don’t know why you decided to use the Field class to get the id instead of the more practical Resources.getIdetifier method:

for(int i=0; i<ROW_COUNT; i++) {
    for(int j=0; j<COL_COUNT; j++) {
        String a = ROWS[i];
        String b = COLS[j];
        int editTextId = getResources().getIdentifier("box" + a + b , "id", getPackageName());
        EditText et=(EditText)findViewById(editTextId);    
        et.setText("");
    }
}

Or, based on those EditText being in a TableLayout, you could just pass a reference to the TableLayout into a method which will traverse it with the method getChildAt(position).