android change text color of items in spinner

问题:

I have a spinner where in certain conditions some options should not be selectable. I have the code to make items not selectable but it does not grey out text color to specify that the item is not selectable. How would I change the text color of the items in the spinner that should be disabled? Here is the code:

public class main extends Activity {

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    PatchedSpinner pSpinner = (PatchedSpinner) findViewById(R.id.spinner2);
    ArrayList<String> testarray = new ArrayList<String>();
    testarray.add("item0");
    testarray.add("item1");
    testarray.add("item2");
    testarray.add("item3");

    ArrayAdapter<String> spinnerAdapter = new ArrayAdapter<String>(this, 
            android.R.layout.simple_spinner_dropdown_item, testarray) { 

        @Override
        public boolean isEnabled(int position) {
            return position != 1;
        }

        public boolean areAllItemsEnabled() { 
            return false; 
        } 
    };
    pSpinner.setAdapter(spinnerAdapter);
}

Below is the Custom Spinner Class used to create a spinner that is able to disable certain items in the spinner.

public class PatchedSpinner extends Spinner {

    public PatchedSpinner(Context context, AttributeSet attrs, int defStyle) { 
        super(context, attrs, defStyle); 
    } 

    public PatchedSpinner(Context context) { 
        super(context); 
    } 

    public PatchedSpinner(Context context, AttributeSet attrs) { 
        super(context, attrs); 
    }

    @Override 
    public boolean performClick() {
        // this line removed, we do not want to delegate the click to the spinner.
        // boolean handled = super.performClick(); 

        Context context = getContext();

        final DropDownAdapter adapter = new DropDownAdapter(getAdapter());

        CharSequence mPrompt = getPrompt();

        AlertDialog.Builder builder = new AlertDialog.Builder(context); 
        if (mPrompt != null) { 
            builder.setTitle(mPrompt); 
        } 
        builder.setSingleChoiceItems(adapter, getSelectedItemPosition(), this).show();

        return true; 
    }

    private static class DropDownAdapter implements ListAdapter, SpinnerAdapter { 
        private SpinnerAdapter mAdapter;

        public DropDownAdapter(SpinnerAdapter adapter) { 
            mAdapter = adapter; 
        }

        public int getCount() { 
            return mAdapter == null ? 0 : mAdapter.getCount(); 
        }

        public Object getItem(int position) { 
            return mAdapter == null ? null : mAdapter.getItem(position); 
        }

        public long getItemId(int position) { 
            return mAdapter == null ? -1 : mAdapter.getItemId(position); 
        }

        public View getView(int position, View convertView, ViewGroup parent) { 
            return getDropDownView(position, convertView, parent); 
        }

        public View getDropDownView(int position, View convertView,ViewGroup parent) { 
            if (mAdapter == null) {
                return null;
            }
            mAdapter.getDropDownView(position, convertView, parent);
        }

        public boolean hasStableIds() { 
            return mAdapter != null && mAdapter.hasStableIds(); 
        }

        public void registerDataSetObserver(DataSetObserver observer){ 
            if (mAdapter != null) { 
                mAdapter.registerDataSetObserver(observer); 
            } 
        }

        public void unregisterDataSetObserver(DataSetObserver observer) { 
            if (mAdapter != null) { 
                mAdapter.unregisterDataSetObserver(observer); 
            } 
        }

        // PATCHED 
        public boolean areAllItemsEnabled() { 
            if (mAdapter instanceof BaseAdapter) { 
                return ((BaseAdapter) mAdapter).areAllItemsEnabled(); 
            } else { 
                return true; 
            } 
        }

        // PATCHED 
        public boolean isEnabled(int position) { 
            if (mAdapter instanceof BaseAdapter) { 
                return ((BaseAdapter) mAdapter).isEnabled(position); 
            } else { 
                return true; 
            } 
        }

        public int getItemViewType(int position) { 
            return 0; 
        }

        public int getViewTypeCount() { 
            return 1; 
        }

        public boolean isEmpty() { 
            return getCount() == 0; 
        } 
    }
}

回答1:

I figured out that to make this work you have to override the getDropDownView when setting up the ArrayAdapter in the main activity.

public class main extends Activity {  
     @Override 
     public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);   
        setContentView(R.layout.main);  

        PatchedSpinner pSpinner = (PatchedSpinner) findViewById(R.id.spinner2); 
        ArrayList<String> testarray = new ArrayList<String>();
        testarray.add("item0");
        testarray.add("item1");
        testarray.add("item2");
        testarray.add("item3");
        ArrayAdapter<String> spinnerAdapter = new ArrayAdapter<String>(this,android.R.layout.simple_spinner_dropdown_item, testarray) {

           @Override      
           public boolean isEnabled(int position) {
               return position != 1;                             
           }

           @Override                
           public boolean areAllItemsEnabled() {
               return false;
           }

           @Override
           public View getDropDownView(int position, View convertView, ViewGroup parent){
               View v = convertView;
               if (v == null) {
                   Context mContext = this.getContext();
                   LayoutInflater vi = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
                   v = vi.inflate(R.layout.row, null);
               }

               TextView tv = (TextView) v.findViewById(R.id.spinnerTarget);
               tv.setText(testarray.get(position));

               switch (position) {
                   case 0:
                       tv.setTextColor(Color.RED);  
                       break; 
                   case 1:
                       tv.setTextColor(Color.BLUE);
                       break;
                   default:
                       tv.setTextColor(Color.BLACK);
                       break;
               }
               return v;  
           }              
        };

        pSpinner.setAdapter(spinnerAdapter); 
} 

The layout that is being inflated is a custom layout called row.xml. it is used to set the display for the dropdown view.

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/spinnerTarget"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textSize="14pt" />

回答2:

For anyone that wants to use the original provided android spinner.

public class main extends Activity { 

    private Spinner _spinnerMethod;

    String[] _methodStrings = new String[]{"Item A", "Item B:False","Item C:False","Last Item"};

    @Override 
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);   
        setContentView(R.layout.main);     

        CreateSpinner();
    }

    public void CreateSpinner()
    {       
    _spinnerMethod = (Spinner) findViewById(R.id.spinner_edit_death_method);
    final ArrayList<String> reasonArray = new ArrayList<String>();
    for(int i = 0; i <_methodStrings.length;i ++)
    {
        reasonArray.add(_methodStrings[i]);
    }

    ArrayAdapter<String> methodAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, reasonArray)
        {

            @Override      
            public boolean isEnabled(int position) {
                String val = reasonArray.get(position);
                // In my case added :False to the end of strings I wanted effected for some call
                boolean isFalse = val.contains(":False");                   
                return !isFalse; 
            }

            @Override                
            public boolean areAllItemsEnabled() {
                return false;
            }

            @Override
            public View getDropDownView(int position, View convertView,android.view.ViewGroup parent){
                View v = convertView;
                if (v == null) {
                    Context mContext = this.getContext();
                    LayoutInflater vi = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
                    // Androids orginal spinner view item
                    v = vi.inflate(android.R.layout.simple_spinner_dropdown_item, null);
                }
                // The text view of the spinner list view
                TextView tv = (TextView) v.findViewById(android.R.id.text1);
                String val = reasonArray.get(position); 
                // remove the extra text here
                tv.setText(val.replace(":False", ""));

                boolean disabled = !isEnabled(position);
                if(disabled){tv.setTextColor(Color.GRAY);}
                else{tv.setTextColor(Color.BLACK);}

                return v;  
            }
        };
    methodAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    _spinnerMethod.setAdapter(methodAdapter);
    }       
}