从android.com运行hellogridview的问题

Question

我之前对此发布了一个问题，现在我没有任何错误，但是当我尝试在模拟的android设备上运行我的应用程序时，出现一个错误，提示说

抱歉，应用程序Hello Grid View（进程com.HelloGridView）已意外停止。 请再试一次。

这是文件树，文件将在以后出现：

HelloGridView  
src  
com.HelloGridView  
HelloGridView.java  
ImageAdapter.java  
gen  
Android 2.2  
assets  
res  
drawable( with all the pics)  

HelloGridView.java

package com.HelloGridView;

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

public class HelloGridView extends Activity {
    /** Called when the activity is first created. */
    @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.main);

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

            gridview.setOnItemClickListener(new AdapterView.OnItemClickListener() {
                public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
                    Toast.makeText(HelloGridView.this, "" + position, Toast.LENGTH_SHORT).show();
                }
            });
        }
    }

ImageAdapter.java

package com.HelloGridView;

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

public class ImageAdapter extends BaseAdapter {
    private Context mContext;

    public ImageAdapter(Context c) {
        mContext = c;
    }

    public ImageAdapter(HelloGridView c) {
        // TODO Auto-generated constructor stub
    }

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

    public Object getItem(int position) {
        return null;
    }

    public long getItemId(int position) {
        return 0;
    }

    // create a new ImageView for each item referenced by the Adapter
    public View getView(int position, View convertView, ViewGroup parent) {
        ImageView imageView;
        if (convertView == null) {  // if it's not recycled, initialize some attributes
            imageView = new ImageView(mContext);
            imageView.setLayoutParams(new GridView.LayoutParams(85, 85));
            imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
            imageView.setPadding(8, 8, 8, 8);
        } else {
            imageView = (ImageView) convertView;
        }

        imageView.setImageResource(mThumbIds[position]);
        return imageView;
    }

    // references to our images
    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
    };
}  

这是我的main.xml

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

Answer 1

如果从ImageAdapter类中删除这些行，则一切正常。

public ImageAdapter(HelloGridView c) {
    // TODO Auto-generated constructor stub
}

正在调用此构造函数，并且未设置您的Context。 我不是Java专家，但我认为它被调用是因为它更具体。

您已经有了此构造函数，它将处理设置上下文。

public ImageAdapter(Context c) {
    mContext = c;
}

另一个解决方案是将您现有的构造函数更改为此，它也将起作用。

public ImageAdapter(HelloGridView c) {
    mContext = c;
}

Answer 2

问题是由于教程“将图像文件保存到项目的res / drawable /目录中”这一行而造成的。

在您的项目中，您没有此文件夹，而是/ drawable-hdpi（ldpi ...等）

因此，请解决该问题，只需在res目录下创建一个新文件夹并将其命名为“ drawable”，然后将图像导入到该文件夹​​中即可。

要么

在AndroidManifest.xml中，将“ @ drawable / icon”行更新到您的文件夹中。