Question

下面的代码不会引发任何错误但是当我在模拟器中运行应用程序时，它会在应用程序中显示任何图像

MainActivity

package com.example.gridview;

import java.util.ArrayList;

import android.os.Bundle;
import android.app.Activity;
import android.content.Context;
import android.content.res.Resources;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Adapter;
import android.widget.ArrayAdapter;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;
import android.widget.AdapterView; 

public class MainActivity extends Activity {

    GridView mygrid;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mygrid=(GridView) findViewById(R.id.gridView1);
        mygrid.setAdapter(new demadap(this));

    }



    class coundic
    {
        String name;
        int image;
        public coundic(String name, int image)
        {
            this.name=name;
            this.image=image;
        }
    }

    class demadap extends BaseAdapter
    {

    ArrayList<coundic> list;
    Context context;
    String[] imagename;
    int[] image;

    public demadap(Context context)
    {
        this.context=context;

        list=new ArrayList<coundic>();
        Resources res=context.getResources(); 
        String[] tempactor=res.getStringArray(R.array.actor);
        int[] image={R.drawable.meme1, R.drawable.meme2, R.drawable.meme3, R.drawable.meme4};

        for(int i=0;i<4;i++)
        {
            coundic tempdata=new coundic(tempactor[i],image[i]);
        }
    }
    @Override
    public int getCount() {
        // TODO Auto-generated method stub
        return list.size();
    }

    @Override
    public Object getItem(int arg0) {
        // TODO Auto-generated method stub
        return list.get(arg0);
    }

    @Override
    public long getItemId(int arg0) {
        // TODO Auto-generated method stub
        return arg0;
    }
    class viewholder
    {
        ImageView actor;
        public viewholder(View v) {
            actor=(ImageView) v.findViewById(R.id.imageView1);

        }
    }

    @Override
    public View getView(int arg0, View arg1, ViewGroup arg2) 
    {
        View row=arg1;
        viewholder holder=null;
        if(row==null)
        {
            LayoutInflater inflater=(LayoutInflater) context.getSystemService(LAYOUT_INFLATER_SERVICE);
             row=inflater.inflate(R.layout.single_image, arg2, false);
             holder=new viewholder(row);
             row.setTag(holder);
        }
        else
        {
            holder=(viewholder) row.getTag();
        }
        coundic temp=list.get(arg0);
        holder.actor.setImageResource(temp.image);

        return row;
    }

}

string.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="app_name">gridview</string>
    <string name="action_settings">Settings</string>
    <string name="hello_world">Hello world!</string>
    <string-array name="actor">
        <item>actor1</item>
        <item>actor2</item>
        <item>actor3</item>
        <item>actor4</item>
    </string-array>

</resources>

activitymain.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <GridView
        android:id="@+id/gridView1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:numColumns="auto_fit"
        android:horizontalSpacing="0dp"
        android:verticalSpacing="0dp"
        android:stretchMode="spacingWidthUniform">
    </GridView>

</RelativeLayout>

singleimage.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <ImageView
        android:id="@+id/imageView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/meme1"/>

</RelativeLayout>

的manifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.gridview"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="14"
        android:targetSdkVersion="18" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.example.gridview.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

Answer 1

只需更改你的for循环，如下所示：

      for(int i=0;i<image.length;i++)
        {
            coundic tempdata=new coundic(tempactor[i],image[i]);
        }

只需更改ViewHolder，如下所示：

class viewholder
    {
        ImageView actor;
   }

在getView方法中写如下：

@Override
public View getView(int arg0, View arg1, ViewGroup arg2) 
{
    View row=arg1;
    viewholder holder=null;
    if(row==null)
    {
        LayoutInflater inflater=(LayoutInflater) context.getSystemService(LAYOUT_INFLATER_SERVICE);
         row=inflater.inflate(R.layout.single_image, arg2, false);
         holder=new viewholder();
         holder.actor=(ImageView) row.findViewById(R.id.imageView1);
         row.setTag(holder);
    }
    else
    {
        holder=(viewholder) row.getTag();
    }
    coundic temp=list.get(arg0);
    holder.actor.setImageResource(temp.image);

    return row;
}

Answer 2

只需删除 activitymain.xml

中的行

android:stretchMode="spacingWidthUniform"

还在demadap构造函数的for循环中添加list.add(tempdata)。

GridView应用程序未显示图像。以下是我的应用程序代码

2 个答案: