以编程方式添加视图的 Android ViewHolder 模式

Question

我正在创建一个 FrameLayout，然后添加两个视图（一个 ImageView 和一个 TextView）。

我在 getView() 上的代码：

  public View getView(int position, View convertView, ViewGroup parent) {
    ImageView imageView;
    TextView textView1;

    int new_width = wid/2;
    int textview_id=0;

    FrameLayout frame_layout = new FrameLayout(mContext);  // Instantiate the parent
    frame_layout.setLayoutParams(new GridView.LayoutParams(android.widget.FrameLayout.LayoutParams.MATCH_PARENT, 
                    android.widget.FrameLayout.LayoutParams.MATCH_PARENT));

    textView1 = new TextView(mContext); textView1.setId(position); 
    textView1.setText("Set Wallpaper");
    textView1.setTextColor(mContext.getResources().getColor(R.color.set_wallpaper_colors));
    textView1.setVisibility(View.INVISIBLE);
    textView1.setTypeface(textView1.getTypeface(), Typeface.BOLD);


    FrameLayout.LayoutParams textview_params = new FrameLayout.LayoutParams(
            LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
    textview_params.gravity = Gravity.CENTER;


    FrameLayout.LayoutParams imageview_params = new FrameLayout.LayoutParams(
            new_width -5, new_width -5 );


        imageView = new ImageView(mContext);
        //imageView.setLayoutParams(new GridView.LayoutParams(new_width - 5, new_width -5));
        imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
        imageView.setPadding(0, 0, 0, 0);


    imageView.setImageResource(mThumbIds[position]);

    frame_layout.addView(imageView, imageview_params);
    frame_layout.addView(textView1, textview_params);

    return frame_layout;
}

我应该如何更改它以使用 ViewHolder 类。没有可膨胀的布局。

Answer 1

你的代码应该是这样的

static class ViewHolder {
    TextView textView1;
    ImageView imageView1;
}

@Override
public View getView(final int row, View convertView, final ViewGroup parent) {
    ViewHolder holder = null;
    FrameLayout frame_layout = (FrameLayout) convertView;
    if (frame_layout == null) {
        holder = new ViewHolder();
        holder.textView1 = new  TextView(mContext);
        holder.imageView1 = new ImageView(mContext);

        frame_layout.setTag(holder);
    }
    else {
        holder = (ViewHolder) frame_layout.getTag();    
    }

    holder.textView1.setText("Set Wallpaper");
    holder.textView1.setTextColor(mContext.getResources().getColor(R.color.set_wallpaper_colors));
    holder.textView1.setVisibility(View.INVISIBLE);
    holder.textView1.setTypeface(holder.textView1.getTypeface(), Typeface.BOLD);

    FrameLayout.LayoutParams textview_params = new FrameLayout.LayoutParams(
            LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
    textview_params.gravity = Gravity.CENTER;

    FrameLayout.LayoutParams imageview_params = new FrameLayout.LayoutParams(
        new_width -5, new_width -5 );

    holder.imageView1.setScaleType(ImageView.ScaleType.CENTER_CROP);
    holder.imageView1.setPadding(0, 0, 0, 0);

    holder.imageView1.setImageResource(mThumbIds[position]);

    frame_layout.addView(holder.imageView1, imageview_params);
    frame_layout.addView(holder.textView1, textview_params);

    return frame_layout;
}