- Unable to start activity componentInfo
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各位帮忙看一下,新手,急。。。。
启动程序时抛出这样的异常Unable to start activity ComponentInfo{com.kevin.test/com.kevin.test.Ex_07}:java.lang.NullPointerException
代码如下:
[code="java"]
public class Ex_07 extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.setContentView(R.layout.main);
Gallery gallery = (Gallery)findViewById(R.id.mygallery);
gallery.setAdapter(new ImageAdapter(this,getSD()));
}
private List getSD(){
List it = new ArrayList();
File file = new File("/sdcrad/photo/");
File[] files = file.listFiles();for(int i = 0 ; i < files.length; i++){ File f = files[i]; if(getImageFile(f.getPath())) it.add(f.getPath()); } return it; } private boolean getImageFile(String fname){ boolean re; String end = fname.substring(fname.lastIndexOf(".")+1,fname.length()).toLowerCase(); if(end.equals("jpg")||end.equals("gif")||end.equals("png")||end.equals("jpeg")||end.equals("bmp")){ re = true; }else{ re = false; } return re; }
}
[/code]
[code="java"]
package com.kevin.test.adapter;import java.util.List;
import com.kevin.test.R;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.Gallery;
import android.widget.ImageView;public class ImageAdapter extends BaseAdapter {
private int mGalleryItemBackground;
private Context mContext;
private List list;public ImageAdapter(Context c,List<String> list){ mContext = c; this.list = list; // get the properties defined in attrs.xml TypedArray typedArray = mContext.obtainStyledAttributes(R.styleable.Gallery); // get Gallery's id mGalleryItemBackground = typedArray.getResourceId(R.styleable.Gallery_android_galleryItemBackground, 0); typedArray.recycle(); } @Override public int getCount() { // TODO Auto-generated method stub return list.size(); } @Override public Object getItem(int position) { // TODO Auto-generated method stub return position; } @Override public long getItemId(int position) { // TODO Auto-generated method stub return position; } @Override public View getView(int position, View convertView, ViewGroup parent) { // TODO Auto-generated method stub ImageView i = new ImageView(mContext); Bitmap bm = BitmapFactory.decodeFile(list.get(position).toString()); i.setImageBitmap(bm); i.setScaleType(ImageView.ScaleType.FIT_XY); i.setLayoutParams(new Gallery.LayoutParams(136, 88)); i.setBackgroundResource(mGalleryItemBackground); return i; }
}
[/code]
androidMainifest.xml文件
[code="java"]
<?xml version="1.0" encoding="utf-8"?>
package="com.kevin.test"
android:versionCode="1"
android:versionName="1.0"><application android:icon="@drawable/icon" android:label="@string/app_name"> <activity android:name=".Ex_07" 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>
[/code]