列表視圖行在加載和滾動時獲得混合顏色

Question

我根據其中一個孩子的文本值設置行的背景顏色。 但是，無論文本值如何，都會設置多個背景。 滾動上下時會變得更糟。 適配器的代碼：

package com.test.app;

import java.util.ArrayList;

import android.content.Context;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;

public class MyBaseAdapter extends BaseAdapter {

    private LayoutInflater mInflater = null;
    private ArrayList<String[]> mItems = new ArrayList<String[]>();

    public MyBaseAdapter(Context context, ArrayList<String[]> items) {
         mItems = items;
         mInflater = LayoutInflater.from(context);
    }

    public void addItem(String[] it) {
        mItems.add(it);
    }

    public void setListItems(ArrayList<String[]> lit) {
        mItems = lit;
    }

    @Override
    public int getCount() {
        return mItems.size();
    }

    @Override
    public Object getItem(int position) {
        return mItems.get(position);
    }

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

    static class ViewHolder {
        public TextView tv0,tv1;
    }

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

        View rowView = null;
        ViewHolder viewHolder;

        if(convertView == null)
        {
            rowView = mInflater.inflate(R.layout.history_row, null);
        }
        else
        {
            rowView = convertView;
        }

        viewHolder = new ViewHolder();

        viewHolder.tv0 = (TextView)rowView.findViewById(R.id.textView0);
        viewHolder.tv1 = (TextView)rowView.findViewById(R.id.textView1);

        rowView.setTag(viewHolder);

        ViewHolder holder = (ViewHolder) rowView.getTag();

        holder.tv0.setText(mItems.get(position)[0].toString());
        holder.tv1.setText(mItems.get(position)[1].toString());

        if(holder.tv1.getText().equals("0"))
        {
            rowView.setBackgroundColor(0xAA777777);
            // Only the row containing "0" should be colored, yet it colors multiple, random rows.
        }

        return rowView;
    }

}

Answer 1

如果您只是使用：

if(holder.tv1.getText().equals("0")) {
            rowView.setBackgroundColor(0xAA777777);
            // Only the row containing "0" should be colored, yet it colors multiple, random  rows.
}

這確實會使包含0的行具有該特定顏色，但是當您向上和向下滾動列表時，具有此顏色的此特定行將被回收並最終到達不應該的位置。 正確的方法是，如果行不包含0 ，則為行提供默認顏色，以便覆蓋可能的回收視圖的錯誤顏色：

if(holder.tv1.getText().equals("0")) {
            rowView.setBackgroundColor(0xAA777777);
            // Only the row containing "0" should be colored, yet it colors multiple, random  rows.
} else {
   rowView.setBackgroundColor(/*Here the default color will be*/)
   // This row doesn't contain 0 so it must have the default color.
  // Because you could be dealing with a recycled view(that has the above color)
 // then we must revert the color to the default to be sure we end up with the correct color.
}

ViewHolder模式的正確代碼是：

    View rowView = convertView;
    ViewHolder viewHolder;

    if(rowView == null) {
        rowView = mInflater.inflate(R.layout.history_row, parent, false);
        viewHolder = new ViewHolder();
        viewHolder.tv0 = (TextView)rowView.findViewById(R.id.textView0);
        viewHolder.tv1 = (TextView)rowView.findViewById(R.id.textView1);
        rowView.setTag(viewHolder);
    } else {
        viewHolder = (ViewHolder) rowView.getTag();    
    }             

然后使用viewHolder對象設置行的數據。

Answer 2

你可以嘗試一下，設置為ListView： android:cacheColorHint="#00000000"