Question

尝试使用我创建的视图构建一个简单的网格。视图看起来像多米诺骨牌，这是定义它们扩展视图的类

public class Domino extends View{

    private Paint paint;

    public Domino(Context context) {
        super(context);
        init();
    }

    public void init(){
        paint = new Paint();
        paint.setTextSize(12);
        paint.setColor(0xFF668800);
        paint.setStyle(Paint.Style.FILL);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        invalidate(); 
    }

}

然后在数组适配器中我尝试像这样构建它们

private class CustomAdapter extends ArrayAdapter<String> {

    private Context mContext;

    private int tileW, tileH;


    private List<String> list = new ArrayList<String>();

    public CustomAdapter(Context context, int textViewResourceId, List<String> objects) {
        super(context, textViewResourceId, objects);

        this.mContext = context;
        this.list = objects;

        // we need to do some calculation to get accurate screen dimensions if we're going fullscreen
        DisplayMetrics displayMetrics = new DisplayMetrics();
        ((WindowManager) getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay().getMetrics(displayMetrics);


        this.tileW = displayMetrics.widthPixels / 4;
        this.tileH = tileW/2;

    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        Domino domino;

        if (convertView == null) {
            // if it's not recycled, initialize some attributes

            domino = new Domino(mContext);

            domino.setLayoutParams(new GridView.LayoutParams(this.tileW, this.tileH));
            domino.measure(this.tileW, this.tileH);

        }
        else {

            domino = (Domino) convertView;
        }

        String colorString = list.get(position);

        int rid = 0;

        // figure out what color we're going to use
        if (colorString.equals("r")) {
            rid = R.drawable.grid_red;
        }
        else if (colorString.equals("o")) {
            rid = R.drawable.grid_orange;
        }
        else if (colorString.equals("y")) {
            rid = R.drawable.grid_yellow;
        }
        else if (colorString.equals("g")) {
            rid = R.drawable.grid_green;
        }
        else if (colorString.equals("b")) {
            rid = R.drawable.grid_blue;
        }
        else if (colorString.equals("i")) {
            rid = R.drawable.grid_indigo;
        }
        else if (colorString.equals("v")) {
            rid = R.drawable.grid_violet;
        }
        else {
            rid = R.color.black;
        }

        return domino;
    }

}

但是我没有看到任何内容，我想以编程方式设置数组适配器的高度和宽度。我错过了什么？

Answer 1

// Replace this piece of code see what happens.

if (convertView == null) {
    // if it's not recycled, initialize some attributes

    domino = new Domino(mContext);

    domino.setLayoutParams(new GridView.LayoutParams(this.tileW, this.tileH));
    domino.measure(this.tileW, this.tileH);
    convertView.setTag(domino);
} else {
   domino = (Domino) convertView.getTag();
}

如何为一个充满自定义视图的网格充气？

1 个答案: