java - 将 ViewHolder 与 ListView 结合使用

Question

我正在使用 ListView 来列出文本和图像，但我想使用 ViewHolder 使滚动更加平滑我已经尝试过，但不太清楚我必须如何修改代码

我尝试的一些图像没有显示

@Override
public int getCount() {
    return text1.length;
}

@Override
public Object getItem(int position) {
    return text1[position];
}

@Override
public long getItemId(int position) {
    return 0;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    LayoutInflater infla=getActivity().getLayoutInflater();

    View v = infla.inflate(R.layout.list_view_layout, null);

    TextView tv1 = (TextView) v.findViewById(R.id.textView1);
    ImageView iv1 = (ImageView) v.findViewById(R.id.imageView1);
    TextView tv2 = (TextView) v.findViewById(R.id.textView2);
    ImageView iv2 = (ImageView) v.findViewById(R.id.imageView2);
    TextView tv3 = (TextView) v.findViewById(R.id.textView3);
    ImageView iv3 = (ImageView) v.findViewById(R.id.imageView3);
    TextView tv4 = (TextView) v.findViewById(R.id.textView4);
    ImageView iv4 = (ImageView) v.findViewById(R.id.imageView4);
    TextView tv5 = (TextView) v.findViewById(R.id.textView5);
    ImageView iv5 = (ImageView) v.findViewById(R.id.imageView5);
    TextView tv6 = (TextView) v.findViewById(R.id.textView6);
    ImageView iv6 = (ImageView) v.findViewById(R.id.imageView6);
    TextView tv7 = (TextView) v.findViewById(R.id.textView7);
    ImageView iv7 = (ImageView) v.findViewById(R.id.imageView7);

    tv1.setText(text1[position]);
    iv1.setImageResource(text2[position]);
    tv2.setText(text3[position]);
    iv2.setImageResource(text4[position]);
    tv3.setText(text5[position]);
    iv3.setImageResource(text6[position]);
    tv4.setText(text7[position]);
    iv4.setImageResource(text8[position]);
    tv5.setText(text9[position]);
    iv5.setImageResource(text10[position]);
    tv6.setText(text11[position]);
    iv6.setImageResource(text12[position]);
    tv7.setText(text13[position]);
    iv7.setImageResource(text14[position]);

    if(text2[position]==R.drawable.ic_star){
        iv1.setVisibility(View.GONE);
    }if(text3[position].matches("")) {
        tv2.setVisibility(View.GONE);
    }if(text4[position]==R.drawable.ic_star){
        iv2.setVisibility(View.GONE);
    }if(text5[position].matches("")) {
        tv3.setVisibility(View.GONE);
    }if(text6[position]==R.drawable.ic_star){
        iv3.setVisibility(View.GONE);
    }if(text7[position].matches("")){
        tv4.setVisibility(View.GONE);
    }if(text8[position]==R.drawable.ic_star){
        iv4.setVisibility(View.GONE);
    }if(text9[position].matches("")){
        tv5.setVisibility(View.GONE);
    }if(text10[position]==R.drawable.ic_star){
        iv5.setVisibility(View.GONE);
    }if(text11[position].matches("")){
        tv6.setVisibility(View.GONE);
    }if(text12[position]==R.drawable.ic_star){
        iv6.setVisibility(View.GONE);
    }if(text13[position].matches("")){
        tv7.setVisibility(View.GONE);
    }if(text14[position]==R.drawable.ic_star){
        iv7.setVisibility(View.GONE);
    }

    return v;
}

Answer 1

技巧:

@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if( convertView == null ){
    convertView = LayoutInflater.from(getActivity()).inflate(R.layout.list_view_layout, null);
    holder = new ViewHolder();
    holder.tv=(TextView) convertView.findViewById(R.id.textView);
    holder.iv=(ImageView) convertView.findViewById(R.id.imageView);
    ...
    convertView.setTag(holder);
}else {
    holder = (ViewHolder)convertView.getTag();
}

holder.tv.setText(text1[position]);
holder.iv.setImageResource(text2[position]);
...
//handle with your widgets cached in ViewHolder
return convertView;

}

并且ViewHolder在这里:

public class ViewHolder{
    TextView tv;
    ImageView iv;
}