android更改微调器中项目的文本颜色

Question

我有一个微调器，在某些情况下，某些选项不应该是可选的。我有使项目不可选择的代码，但它不会使文本颜色变灰以指定该项目不可选择。如何更改微调器中应禁用的项目的文本颜色？这是代码:

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);
}

下面是用于创建能够禁用微调器中某些项目的微调器的自定义微调器类。

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; 
        } 
    }
}

Answer 1

我发现要完成这项工作，您必须在主 Activity 中设置 ArrayAdapter 时覆盖 getDropDownView。

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); 
} 

正在扩充的布局是一个名为 row.xml 的自定义布局。它用于设置下拉 View 的显示。

<?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" />