Question

我试图练习在Android Studio中使用GridView，我不知道为什么我会一直得到这个例外。

这是我主要课程的代码。

package com.example.chetam.gokalsapp;

    import android.os.Bundle;
    import android.app.Activity;
    import android.view.View;
    import android.widget.AdapterView;
    import android.widget.GridView;
    import android.widget.Toast;

    public class Products extends Activity {
        GridView grid;
        String[] web = {
                "Google",
                "Github",
                "Instagram",
                "Facebook",
                "Flickr",
                "Pinterest",
                "Quora",
                "Twitter",
                "Vimeo",
                "WordPress",
                "Youtube",
                "Stumbleupon",
                "SoundCloud",
                "Reddit",
                "Blogger"

        } ;
        int[] imageId = {
                R.drawable.v,
                R.drawable.img,
                R.drawable.img1,
                R.drawable.img2,
                R.drawable.img3,
                R.drawable.v,
                R.drawable.img,
                R.drawable.img1,
                R.drawable.img2,
                R.drawable.img3,
                R.drawable.v,
                R.drawable.img,
                R.drawable.img1,
                R.drawable.img2,
                R.drawable.img3    
        };    

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

            grid=(GridView)findViewById(R.id.grid);

            CustomGrid adapter = new CustomGrid(Products.this, web, imageId);
            grid.setAdapter(adapter);

            grid.setOnItemClickListener(new AdapterView.OnItemClickListener() {

                @Override
                public void onItemClick(AdapterView<?> parent, View view,
                                        int position, long id) {
                    Toast.makeText(Products.this, "You Clicked at " +web[+ position], Toast.LENGTH_SHORT).show();

                }
            });    
        }    
    }

以下是我的主要XML文件的代码

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.chetam.gokalsapp.Products">

    <GridView
        android:numColumns="auto_fit"
        android:gravity="center"
        android:columnWidth="100dp"
        android:stretchMode="columnWidth"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:id="@+id/grid"
        />    
</RelativeLayout>

这是我的布局文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="5dp"
    android:gravity="center_horizontal"
    android:orientation="vertical">    

    <ImageView
        android:id="@+id/grid_image"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:layout_marginTop="15dp">
    </ImageView>

    <TextView
        android:id="@+id/grid_text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="5dp"
        android:textSize="12sp" >
    </TextView>

</LinearLayout>

这是我的适配器类

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

public class CustomGrid extends BaseAdapter{
    private Context mContext;
    private final String[] web;
    private final int[] Imageid;

    public CustomGrid(Context c,String[] web,int[] Imageid ) {
        mContext = c;
        this.Imageid = Imageid;
        this.web = web;
    }

    @Override
    public int getCount() {
        // TODO Auto-generated method stub
        return web.length;
    }

    @Override
    public Object getItem(int position) {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public long getItemId(int position) {
        // TODO Auto-generated method stub
        return 0;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        // TODO Auto-generated method stub
        View grid;
        LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

        if (convertView == null) {

            grid = new View(mContext);
            grid = inflater.inflate(R.layout.grid_single, null);
            TextView textView = (TextView) grid.findViewById(R.id.grid_text);
            ImageView imageView = (ImageView)grid.findViewById(R.id.grid_image);
            imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
            imageView.setPadding(8,8,8,8);
            textView.setText(web[position]);
            imageView.setImageResource(Imageid[position]);
        }
        else
        {
            grid = (View) convertView;
        }

        return grid;
    }
}

Answer 1

将网格onClickListener替换为：

 grid.setOnItemClickListener(new AdapterView.OnItemClickListener() {

        @Override
        public void onItemClick(AdapterView<?> parent, View view,
                                int position, long id) {
            Toast.makeText(Products.this, "You Clicked at " +web[position], Toast.LENGTH_SHORT).show();

        }
    });

您正在使用整数变量作为String数组的位置。如果你有'+ position'因为你想要一个比位置更高的数字，那么正确的语法是：

grid.setOnItemClickListener(new AdapterView.OnItemClickListener() {

    @Override
    public void onItemClick(AdapterView<?> parent, View view,
                            int position, long id) {
        Toast.makeText(Products.this, "You Clicked at " +web[position + 1], Toast.LENGTH_SHORT).show();

    }
});

AndroidRuntime：FATAL EXCEPTION：主要ID不会

1 个答案: