具有自定义基础适配器的Android Grid View [英] Android Grid View with Custom base Adapter

问题描述

我已经开始学习android开发.我正在制作一个要在网格视图布局中组合显示电影缩略图(图像视图和文本视图)的应用程序，我制作了自定义适配器，但问题是我无法弄清楚如何一起显示图像视图和文本视图.我运行的应用程序显示空白屏幕.我已经尝试了许多解决方案，并且用了很多谷歌搜索，但是我不知道该怎么做，请帮帮我.这是我的代码.

i have started to learn android development. i am making an app in which i want to show movie thumbnails(image view and text view) combined in grid view layout i have made custom adapter but problem is that i cannot figure it out how to show image view and text view together.when i run app it shows blank white screen. i have tried many solution and also googled a lot but i cannot figure it out how to do this please help me. Here is my code.

    public class ImageAdapter extends BaseAdapter {

    private Context mContext;
    private LayoutInflater inflater;
    public ImageAdapter(Context c) {

        mContext = c;
      //
    }

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

    @Override
    public Object getItem(int i) {
        return null;
    }

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

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


        NewHolder holder = null;
        ImageView imageView;

        inflater = (LayoutInflater) mContext.getSystemService( Context.LAYOUT_INFLATER_SERVICE );



        if(convertView==null){
            holder = new NewHolder();

            convertView =inflater.inflate(R.layout.activity_main,viewGroup,false);


            holder.imageView = new ImageView(mContext);
            holder.textView = new TextView(mContext);

            holder.imageView.setLayoutParams(new GridView.LayoutParams(85, 85));
            holder.imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);



         //   holder.textView.setLayoutParams(new GridView.LayoutParams(85, 85));

            convertView.setTag(holder);
            //textView.
           // textView.setText("Hello");
            holder.imageView.setPadding(8, 8, 8, 8);

        }


        else {
            holder = (NewHolder) convertView.getTag();
            //imageView= (ImageView) convertView. ;
            //textView = (TextView) convertView;
        }


//        convertView.
        holder.imageView.setImageResource(mThumbIds[position]);
     //   holder.textView.setText("hello");
        return convertView;



    }



    private Integer[] mThumbIds = {
            R.drawable.sample_2, R.drawable.sample_3,
            R.drawable.sample_4, R.drawable.sample_5,
            R.drawable.sample_6, R.drawable.sample_7,
            R.drawable.sample_0, R.drawable.sample_1,
            R.drawable.sample_2, R.drawable.sample_3,
            R.drawable.sample_4, R.drawable.sample_5,
            R.drawable.sample_6, R.drawable.sample_7,
            R.drawable.sample_0, R.drawable.sample_1,
            R.drawable.sample_2, R.drawable.sample_3,
            R.drawable.sample_4, R.drawable.sample_5,
            R.drawable.sample_6, R.drawable.sample_7
    };

}

主要活动

public class MainActivity extends AppCompatActivity {

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

        GridView gridview = (GridView) findViewById(R.id.grid_view);
        gridview.setAdapter(new ImageAdapter(this));
     //   setContentView(gridview);

    }

持有人阶层

public class NewHolder {

        public ImageView imageView;
        public TextView textView;
    }

主要Xml布局文件

<?xml version="1.0" encoding="utf-8"?>
<GridView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/grid_view"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:columnWidth="90dp"
    android:numColumns="auto_fit"
    android:verticalSpacing="10dp"
    android:horizontalSpacing="10dp"
    android:stretchMode="columnWidth"
    android:gravity="center"
    />

推荐答案

这是您的问题的解决方案. 您使用的适配器不正确.您正在使用此行中的适配器来扩展"GridView".

Here's the solution to your issue. You're using the adapter incorrectly. You're inflating the 'GridView' with the adapter in this line.

convertView =inflater.inflate(R.layout.activity_main,viewGroup,false);

这不是您想要做的.您要制作另一个XML Layout来代表TextView中的每部电影的标题和Imageview

That's no what you want to do. You want to make an other XML Layout that represents each movie's title in a TextView and image in an Imageview

<LinearLayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">
<ImageView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/movieimage"
    android:src="@drawable/moviethumb"/>

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/movie_title"
    android:id="@+id/todo_list_item_bottom_text"
    android:layout_marginTop="10dp"
    android:textSize="12sp"/>
</LinearLayout>

本教程将为您提供帮助.它用于列表视图，但是android中的所有适配器几乎都以相同的方式工作. 适配器教程

This tutorial should help you. It's for a list view but all adapters in android pretty much work the same way. Adapter Tutorial

我注意到您可以改进的地方.将inflator放在convertview == null中.不使用该对象时没有必要创建它.

I noticed a something you can improve upon. Put your inflator inside you convertview == null. There's no point to creating this object when it's not used.

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