Question

我有一个ListView和一个CustomAdapter。所有元素均已成功加载到列表中。现在，我想通过单击外部按钮来更改列表中某个元素的背景色。但是我不知道如何访问列表中的特定项目。

这是CustomAdapter类：

var Players = [];
var list = [];
var count = 0;

// So the code below organizes players by stats. 
// For example, if you call touchdowns, it'll organize from most touchdowns to lowest.
function myFunction(Position, Stat, startingpoint, endingpoint) {
  readRecords(Position, {}, function(records) {
    var temp = 0;
    var name = "";
    for (var i = 0; i < records.length; i++) {
      for (var j = i + 1; j < records.length; j++) {
        if ((records[i])[Stat] < records[j][Stat]) {
          temp = records[i][Stat];
          name = records[i].Player;
          (records[i])[Stat] = (records[j])[Stat];
          records[i].Player = records[j].Player;
          records[j][Stat] = temp;
          records[j].Player = name;
        }
      }
      insertItem(Players, i, (records[i]).Player + " : " + (records[i])[Stat] + " " + Stat + "\n");
    }
    for (var k = startingpoint; k < endingpoint; k++) {
      appendItem(list, Players[k]);
      var x = list.join(" ");
    }

    setText("label2", x);
    for (var l = endingpoint; l >= startingpoint; l--) {
      removeItem(list, Players[l]);
    }
  });

}

// So I made this part cause I thought let's say I had 60 players, and 20 players per page. 
// How would the program know if I wanna see players 0-20 or 20-40 if I click previous? 
// It's to organize that based on a count variable that changes when you click back and forward.
onEvent("button1", "click", function() {
    count = count + 1;
});

onEvent("button2", "click", function() {
    count = count - 1;
});

// And this was supposed to call back my original function to organize stats when I click the next or previous button. 
// Guess this is where my problem is.
function callback(Stats) {
    count = 0;
    setText("label2", "");
    onEvent("button1", "click", function() {
        if (count == 1) {
            myFunction("Quarterbacks", Stats, 40, 69);
        }
    });

    onEvent("button2", "click", function() {
        if (count == 0) {
            myFunction("Quarterbacks", Stats, 0, 40);
        }
    });
}

// Quarterback stats
onEvent("QuarterBackmenu", "change", function() {
    setScreen("OffenseStatScreen");

    if (getText("QuarterBackmenu") == "Touchdowns") {
        setText("label2", "");
        myFunction("Quarterbacks", "Touchdowns", 0, 40);
        setText("QuarterBackmenu", "Quarterback");
        callback("Touchdowns");
    } else if ((getText("QuarterBackmenu") == "Completions")) {
        setText("label2", "");
        myFunction("Quarterbacks", "Completions", 0, 40);
        setText("QuarterBackmenu", "Quarterback");
        callback("Completions");
    }
});

Answer 1

您可以在getView()方法中做到这一点

view.setOnClickListener(new OnClickListener() 
   { 
     @Override
     public void onClick(View v)
         { 
           view.setBackgroundColor(ContextCompat.getColor(this, R.color.yourcolor));
          }
   });

如果视图上有一个按钮，则对该按钮执行侦听器

如果您想从父活动中获取选定的项目视图，则：

yourlistview.setOnItemClickListener(new AdapterView.OnItemClickListener() 
{ 
 @Override 
  public void onItemClick(AdapterView<?>     parent,View view, int position, long id) 
    { 
       selectedposition = position ;
     }
  });


  View view = listView.getAdapter().getView(selectedposition,null,listview);

然后更改背景：

view.setBackgroundColor(ContextCompat.getColor(this, R.color.yourcolor));

请在color.xml文件中定义颜色

如果您的视图不止一个，则创建一个ArrayList<View>并进行一些循环

Answer 2

在您的活动和您的活动中创建一个自定义侦听器界面适配器将实现此功能。

public interface OnClickListenerFromActivity {
    void onActivityButtonClick(int position);
}

在单击按钮时调用侦听器的方法

    mOnClickListenerFromActivity.onActivityButtonClick(mList.getItem(yourPostion));

将此侦听器实现到您的适配器中

public class CustomAdapter extends BaseAdapter implements Activity.OnClickListenerFromActivity {

private Context ctx;
private int resource;
private List<ItemModel> items;


public PreorderListAdapter(Context context, int resource, List<ItemModel> items){
    this.ctx = context;
    this.resource = resource;
    this.items = items;
}

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

@Override
public ItemModel getItem(int position) {
    return items.get(position);
}

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

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

    View view = convertView;

    if(view == null){
        LayoutInflater inflater = (LayoutInflater)ctx.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        view = inflater.inflate(resource, null);
    }


    TextView text1 = (TextView) view.findViewById(R.id.text1);
    TextView text2 = (TextView) view.findViewById(R.id.text2);
    TextView text3 = (TextView) view.findViewById(R.id.text3);

    ItemModel item = items.get(i);

    text1.setText(item.getName());
    text2.setText(item.getOption2());
    text3.setText(item.getOption3());

    return view;
}

public void onActivityButtonClick(int position) {
    // get your item through position and
    // set your color here
}

}

如何在单击按钮时更改列表项的背景颜色？

2 个答案: