Android ListView微粒行背景颜色变化

Question

I have a custom ListView where I need to show Available shift in Green Color and Unavailable shift in Red. I made a custom adapter in it's getView() I am trying to check the value and change the color.

GetView in Custom Adapter looks like this-

public View getView(int position, View convertView, ViewGroup parent) {
    View v = convertView;
    if(v==null){
        v = inflater.inflate(R.layout.simplerow, null);
    }

    ViewHolder holder = null;
    if(convertView == null) {
        holder = new ViewHolder();
        convertView = inflater.inflate(R.layout.simplerow, null);
        holder.textView1 = (TextView) convertView.findViewById(R.id.rowTextView1);
        holder.textView2 = (TextView) convertView.findViewById(R.id.rowTextView2);
        convertView.setTag(holder);
    } else {
        holder = (ViewHolder) convertView.getTag();
    }


        if(objects.get(position).getprop1().equalsIgnoreCase("Shift -3")) {
            ((RelativeLayout)convertView.findViewById(R.id.RelativeLayoutSingleRow)).setBackgroundResource(R.drawable.red_bg);
        }


    holder.textView1.setText(objects.get(position).getprop1());
    holder.textView2.setText(objects.get(position).getprop2());
    return convertView;
}

But the out put I am getting like this -

And whenever I am scrolling color are showing in some other value too.

Answer 1

Replace you getView() by

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

    ViewHolder holder = null;
    if(convertView == null) {
        holder = new ViewHolder();
        convertView = inflater.inflate(R.layout.simplerow, null);
        holder.textView1 = (TextView) convertView.findViewById(R.id.rowTextView1);
        holder.textView2 = (TextView) convertView.findViewById(R.id.rowTextView2);
        convertView.setTag(holder);
    } else {
        holder = (ViewHolder) convertView.getTag();
    }

 /**
  * here check your condtion like this and set color to background no need of for loop
  ***/
        if(objects.get(position).getprop1().equalsIgnoreCase("Shift -3")) {
            ((RelativeLayout)convertView.findViewById(R.id.RelativeLayoutSingleRow)).setBackgroundResource(R.drawable.red_bg);
        }else
       {
              // set normal color here
       }


    holder.textView1.setText(objects.get(position).getprop1());
    holder.textView2.setText(objects.get(position).getprop2());
    return convertView;
}

Answer 2

While you are setting red background for one View you have to set normal background for remaining views by using else case

if(objects.get(position).getprop1().equalsIgnoreCase("Shift -3")) {
        ((RelativeLayout)convertView.findViewById(R.id.RelativeLayoutSingleRow)).setBackgroundResource(R.drawable.red_bg);
 } else{
   //here set normal background for view.
 }

Hope this will helps you.

Answer 3

It is due to View Reuse capability of ListView. If Shift -3 condition is not met you have to set background of the row to default row color since the row with red background can be reused at any position in list.

if (objects.get(position).getprop1().equalsIgnoreCase("Shift -3")) {
            ((RelativeLayout) convertView.findViewById(R.id.RelativeLayoutSingleRow))
                    .setBackgroundResource(R.drawable.red_bg);
        } else {
            //default bg
            ((RelativeLayout) convertView.findViewById(R.id.RelativeLayoutSingleRow))
                    .setBackgroundResource(deafult_bg);
        }

Answer 4

Here is the solution.

public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder = null;
        if (convertView == null) {
            holder = new ViewHolder();
            convertView = inflater.inflate(R.layout.simplerow, null);
            holder.textView1 = (TextView) convertView.findViewById(R.id.rowTextView1);
            holder.textView2 = (TextView) convertView.findViewById(R.id.rowTextView2);
            convertView.setTag(holder);
        } else {
            holder = (ViewHolder) convertView.getTag();
        }


        if (objects.get(position).getprop1().equalsIgnoreCase("Shift -3")) {
            ((RelativeLayout) convertView.findViewById(R.id.RelativeLayoutSingleRow)).setBackgroundResource(R.drawable.red_bg);
        } else {
            //Update to default color
        }

        holder.textView1.setText(objects.get(position).getprop1());
        holder.textView2.setText(objects.get(position).getprop2());
        return convertView;
    }

If the condition is matched set the RED color else set the default color.

Answer 5

You also need to add else part here as below -

for (int i = 1; i < 9 ; i++) {
    if(objects.get(position).getprop1().equalsIgnoreCase("Shift -3")) {
        ((RelativeLayout)convertView.findViewById(R.id.RelativeLayoutSingleRow)).setBackgroundResource(R.drawable.red_bg);
    }
    else{
        ((RelativeLayout)convertView.findViewById(R.id.RelativeLayoutSingleRow)).setB ackgroundResource(R.drawable.green_bg); //your green color
    }
}

Answer 6

You have to use getViewType() . Try this code (I modified your code for you):

@Override
public int getItemViewType(int position) {
    return (objects.get(position).getprop1().equalsIgnoreCase("Shift -3")) ? 1 : 0;
}

@Override
public int getViewTypeCount() {
    return 2;
}        

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

    ViewHolder holder = null;
    int type = getItemViewType(position);
    if(convertView == null) {
        holder = new ViewHolder();
        convertView = inflater.inflate(R.layout.simplerow, null);
        holder.textView1 = (TextView) convertView.findViewById(R.id.rowTextView1);
        holder.textView2 = (TextView) convertView.findViewById(R.id.rowTextView2);
        convertView.setTag(holder);
    } else {
        holder = (ViewHolder) convertView.getTag();
    }

    if(type == 0) {

            //Set here your regular color
    }else {
        ((RelativeLayout)convertView.findViewById(R.id.RelativeLayoutSingleRow)).setBackgroundResource(R.drawable.red_bg);
    }

    holder.textView1.setText(objects.get(position).getprop1());
    holder.textView2.setText(objects.get(position).getprop2());
    return convertView;
}

EDIT: I have to explain. If you don't use getViewType() method and just if statement like other answers here, then if you have many items in your list (enough for scrolling), your items will change the color dynamically while scrolling.