Question

我正在尝试从布局中拍摄图像。当用户选择任何图像时，它将显示在自定义列表视图中。我第一次点击图像时所取得的成就显示在自定义列表视图中，但是当我第二次选择图像时，它会覆盖第一个图像。这是审查的代码

这是我的主要课程

package com.example.zeus_technologies.customlistview;

import android.app.Activity;
import android.content.Context;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View; 
import android.widget.ImageView;
import android.widget.ListView;

public class MainActivity extends Activity {
ListView list;

String[] itemname ={
        "Safari",
};
Integer[] imgid={
        R.drawable.a,
        R.drawable.ab,
        R.drawable.abc,
        R.drawable.abcd,
};


@Override
protected void onCreate(Bundle savedInstanceState) {
 //   list=(ListView)findViewById(R.id.list);

    final Context context=this;
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    list = (ListView) findViewById(R.id.list);
    ImageView[] im = new ImageView[4];
    im[0] = (ImageView) findViewById(R.id.imageview1);
    im[1] = (ImageView) findViewById(R.id.imageview2);
    im[2] = (ImageView) findViewById(R.id.imageview3);
    im[3] = (ImageView) findViewById(R.id.imageview4);

    im[0].setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            CustomListAdapter adapter=new CustomListAdapter((Activity) context,itemname, imgid[0]);

                         list.setAdapter(adapter);

        }
    });
    im[1].setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {


           CustomListAdapter adapter = new CustomListAdapter((Activity) context, itemname, imgid[1]);

            list.setAdapter(adapter);

        }
    });
}

这是我的列表适配器类 package com.example.zeus_technologies.customlistview;

import android.app.Activity;
import android.content.Context;
import android.media.Image;
import android.net.Uri;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;

public class CustomListAdapter extends ArrayAdapter<String> {

private final Activity context;
private final String[] itemname;
private final Integer imgid;
public CustomListAdapter(Activity context,String[] itemname ,Integer imgid)           {
    super(context, R.layout.mylist, itemname);
    // TODO Auto-generated constructor stub

    this.context=context;
    this.itemname=itemname;
   this.imgid=imgid;
}

 public View getView(int position,View view,ViewGroup parent) {
    LayoutInflater inflater=context.getLayoutInflater();
    View rowView=inflater.inflate(R.layout.mylist, null,true);

    //TextView txtTitle = (TextView) rowView.findViewById(R.id.item);
    ImageView imageView = (ImageView) rowView.findViewById(R.id.icon);
    //TextView extratxt = (TextView) rowView.findViewById(R.id.textView1);
    //txtTitle.setText(itemname[position]);
     imageView.setImageResource(imgid);

     ///extratxt.setText("Description "+itemname[position]);
   return rowView;

};

}

还有一件事。我已经尝试从onClickListener中创建适配器对象。但仍然无法正常工作

Answer 1

每次向其添加新项目时，您都不想设置新的适配器，您要做的是将适配器设置为listview一次，并更新基础数据集并调用{{1} }。像这样的东西（伪代码）：

MainActivity

direction: rtl

适配器：

adapter.notifyDataSetChanged();

列表项：

public class MainActivity extends Activity implements View.OnClickListener {

    private List<ListItem> dataSet;

    private ListView list;

    private CustomListAdapter adapter;

    private ImageView imageview1, imageview2, imageview3, imageview4;

    private Integer[] ids = {
        R.drawable.first,
        R.drawable.second,
        R.drawable.third,
        R.drawable.fourth,
    };

    private String[] names = {
        "First",
        "Second",
        "Third",
        "Fourth",
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        list = (ListView) findViewById(R.id.listView);

        dataSet = new ArrayList<>();

        adapter = new CustomListAdapter(this, dataSet);

        list.setAdapter(adapter);

        imageview1 = (ImageView) findViewById(R.id.imageview1);
        imageview2 = (ImageView) findViewById(R.id.imageview2);
        imageview3 = (ImageView) findViewById(R.id.imageview3);
        imageview4 = (ImageView) findViewById(R.id.imageview4);

        imageview1.setOnClickListener(this);
        imageview2.setOnClickListener(this);
        imageview3.setOnClickListener(this);
        imageview4.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {

        int selectedImage;

        if (v == imageview1) {
            selectedImage = 0;
        } else if (v == imageview2) {
            selectedImage = 1;
        } else if (v == imageview3) {
            selectedImage = 2;
        } else {
            selectedImage = 3;
        }

        dataSet.add(new ListItem(names[selectedImage], ids[selectedImage]));
        adapter.notifyDataSetChanged();
    }
}

单击图像后如何在自定义列表视图中添加图像

1 个答案: