您忘记了从xml文件加载元数据的步骤.

这是我在应用程序中用于加载图标包的类的完整源代码,该load方法执行appfilter.xml解析：

package se.amphisys;

import android.content.Intent;

import android.content.pm.ApplicationInfo;

import android.content.pm.PackageManager;

import android.content.pm.ResolveInfo;

import android.content.res.Resources;

import android.graphics.*;

import android.graphics.drawable.BitmapDrawable;

import android.graphics.drawable.Drawable;

import com.google.inject.Inject;

import com.google.inject.Singleton;

import org.xmlpull.v1.XmlPullParser;

import org.xmlpull.v1.XmlPullParserException;

import org.xmlpull.v1.XmlPullParserFactory;

import roboguice.util.Ln;

import java.io.IOException;

import java.io.InputStream;

import java.util.*;

@Singleton

public class IconPackManager

{

@Inject

private android.app.Application mContext;

public class IconPack

{

public String packageName;

public String name;

private boolean mLoaded = false;

private HashMap mPackagesDrawables = new HashMap();

private List mBackImages = new ArrayList();

private Bitmap mMaskImage = null;

private Bitmap mFrontImage = null;

private float mFactor = 1.0f;

Resources iconPackres = null;

public void load()

{

// load appfilter.xml from the icon pack package

PackageManager pm = mContext.getPackageManager();

try

{

XmlPullParser xpp = null;

iconPackres = pm.getResourcesForApplication(packageName);

int appfilterid = iconPackres.getIdentifier("appfilter", "xml", packageName);

if (appfilterid > 0)

{

xpp = iconPackres.getXml(appfilterid);

}

else

{

// no resource found, try to open it from assests folder

try

{

InputStream appfilterstream = iconPackres.getAssets().open("appfilter.xml");

XmlPullParserFactory factory = XmlPullParserFactory.newInstance();

factory.setNamespaceAware(true);

xpp = factory.newPullParser();

xpp.setInput(appfilterstream, "utf-8");

}

catch (IOException e1)

{

Ln.d("No appfilter.xml file");

}

}

if (xpp != null)

{

int eventType = xpp.getEventType();

while (eventType != XmlPullParser.END_DOCUMENT)

{

if(eventType == XmlPullParser.START_TAG)

{

if (xpp.getName().equals("iconback"))

{

for(int i=0; i

{

if (xpp.getAttributeName(i).startsWith("img"))

{

String drawableName = xpp.getAttributeValue(i);

Bitmap iconback = loadBitmap(drawableName);

if (iconback != null)

mBackImages.add(iconback);

}

}

}

else if (xpp.getName().equals("iconmask"))

{

if (xpp.getAttributeCount() > 0 && xpp.getAttributeName(0).equals("img1"))

{

String drawableName = xpp.getAttributeValue(0);

mMaskImage = loadBitmap(drawableName);

}

}

else if (xpp.getName().equals("iconupon"))

{

if (xpp.getAttributeCount() > 0 && xpp.getAttributeName(0).equals("img1"))

{

String drawableName = xpp.getAttributeValue(0);

mFrontImage = loadBitmap(drawableName);

}

}

else if (xpp.getName().equals("scale"))

{

// mFactor

if (xpp.getAttributeCount() > 0 && xpp.getAttributeName(0).equals("factor"))

{

mFactor = Float.valueOf(xpp.getAttributeValue(0));

}

}

else if (xpp.getName().equals("item"))

{

String componentName = null;

String drawableName = null;

for(int i=0; i

{

if (xpp.getAttributeName(i).equals("component"))

{

componentName = xpp.getAttributeValue(i);

}

else if (xpp.getAttributeName(i).equals("drawable"))

{

drawableName = xpp.getAttributeValue(i);

}

}

if (!mPackagesDrawables.containsKey(componentName))

mPackagesDrawables.put(componentName, drawableName);

}

}

eventType = xpp.next();

}

}

mLoaded = true;

}

catch (PackageManager.NameNotFoundException e)

{

Ln.d("Cannot load icon pack");

}

catch (XmlPullParserException e)

{

Ln.d("Cannot parse icon pack appfilter.xml");

}

catch (IOException e) {

e.printStackTrace();

}

}

private Bitmap loadBitmap(String drawableName)

{

int id = iconPackres.getIdentifier(drawableName, "drawable", packageName);

if (id > 0)

{

Drawable bitmap = iconPackres.getDrawable(id);

if (bitmap instanceof BitmapDrawable)

return ((BitmapDrawable)bitmap).getBitmap();

}

return null;

}

private Drawable loadDrawable(String drawableName)

{

int id = iconPackres.getIdentifier(drawableName, "drawable", packageName);

if (id > 0)

{

Drawable bitmap = iconPackres.getDrawable(id);

return bitmap;

}

return null;

}

public Drawable getDrawableIconForPackage(String appPackageName, Drawable defaultDrawable) {

if (!mLoaded)

load();

PackageManager pm = mContext.getPackageManager();

Intent launchIntent = pm.getLaunchIntentForPackage(appPackageName);

String componentName = null;

if (launchIntent != null)

componentName = pm.getLaunchIntentForPackage(appPackageName).getComponent().toString();

String drawable = mPackagesDrawables.get(componentName);

if (drawable != null)

{

return loadDrawable(drawable);

}

else

{

// try to get a resource with the component filename

if (componentName != null)

{

int start = componentName.indexOf("{")+1;

int end = componentName.indexOf("}", start);

if (end > start)

{

drawable = componentName.substring(start,end).toLowerCase(Locale.getDefault()).replace(".","_").replace("/", "_");

if (iconPackres.getIdentifier(drawable, "drawable", packageName) > 0)

return loadDrawable(drawable);

}

}

}

return defaultDrawable;

}

public Bitmap getIconForPackage(String appPackageName, Bitmap defaultBitmap)

{

if (!mLoaded)

load();

PackageManager pm = mContext.getPackageManager();

Intent launchIntent = pm.getLaunchIntentForPackage(appPackageName);

String componentName = null;

if (launchIntent != null)

componentName = pm.getLaunchIntentForPackage(appPackageName).getComponent().toString();

String drawable = mPackagesDrawables.get(componentName);

if (drawable != null)

{

return loadBitmap(drawable);

}

else

{

// try to get a resource with the component filename

if (componentName != null)

{

int start = componentName.indexOf("{")+1;

int end = componentName.indexOf("}", start);

if (end > start)

{

drawable = componentName.substring(start,end).toLowerCase(Locale.getDefault()).replace(".","_").replace("/", "_");

if (iconPackres.getIdentifier(drawable, "drawable", packageName) > 0)

return loadBitmap(drawable);

}

}

}

return generateBitmap(appPackageName, defaultBitmap);

}

private Bitmap generateBitmap(String appPackageName, Bitmap defaultBitmap)

{

// the key for the cache is the icon pack package name and the app package name

String key = packageName + ":" + appPackageName;

// if generated bitmaps cache already contains the package name return it

// Bitmap cachedBitmap = BitmapCache.getInstance(mContext).getBitmap(key);

// if (cachedBitmap != null)

// return cachedBitmap;

// if no support images in the icon pack return the bitmap itself

if (mBackImages.size() == 0)

return defaultBitmap;

Random r = new Random();

int backImageInd = r.nextInt(mBackImages.size());

Bitmap backImage = mBackImages.get(backImageInd);

int w = backImage.getWidth();

int h = backImage.getHeight();

// create a bitmap for the result

Bitmap result = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);

Canvas mCanvas = new Canvas(result);

// draw the background first

mCanvas.drawBitmap(backImage, 0, 0, null);

// create a mutable mask bitmap with the same mask

Bitmap scaledBitmap = defaultBitmap;

if (defaultBitmap != null && (defaultBitmap.getWidth() > w || defaultBitmap.getHeight()> h))

Bitmap.createScaledBitmap(defaultBitmap, (int)(w * mFactor), (int)(h * mFactor), false);

if (mMaskImage != null)

{

// draw the scaled bitmap with mask

Bitmap mutableMask = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);

Canvas maskCanvas = new Canvas(mutableMask);

maskCanvas.drawBitmap(mMaskImage,0, 0, new Paint());

// paint the bitmap with mask into the result

Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);

paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_OUT));

mCanvas.drawBitmap(scaledBitmap, (w - scaledBitmap.getWidth())/2, (h - scaledBitmap.getHeight())/2, null);

mCanvas.drawBitmap(mutableMask, 0, 0, paint);

paint.setXfermode(null);

}

else // draw the scaled bitmap without mask

{

mCanvas.drawBitmap(scaledBitmap, (w - scaledBitmap.getWidth())/2, (h - scaledBitmap.getHeight())/2, null);

}

// paint the front

if (mFrontImage != null)

{

mCanvas.drawBitmap(mFrontImage, 0, 0, null);

}

// store the bitmap in cache

// BitmapCache.getInstance(mContext).putBitmap(key, result);

// return it

return result;

}

}

private HashMap iconPacks = null;

public HashMap getAvailableIconPacks(boolean forceReload)

{

if (iconPacks == null || forceReload)

{

iconPacks = new HashMap();

// find apps with intent-filter "com.gau.go.launcherex.theme" and return build the HashMap

PackageManager pm = mContext.getPackageManager();

List adwlauncherthemes = pm.queryIntentActivities(new Intent("org.adw.launcher.THEMES"), PackageManager.GET_META_DATA);

List golauncherthemes = pm.queryIntentActivities(new Intent("com.gau.go.launcherex.theme"), PackageManager.GET_META_DATA);

// merge those lists

List rinfo = new ArrayList(adwlauncherthemes);

rinfo.addAll(golauncherthemes);

for(ResolveInfo ri : rinfo)

{

IconPack ip = new IconPack();

ip.packageName = ri.activityInfo.packageName;

ApplicationInfo ai = null;

try

{

ai = pm.getApplicationInfo(ip.packageName, PackageManager.GET_META_DATA);

ip.name = mContext.getPackageManager().getApplicationLabel(ai).toString();

iconPacks.put(ip.packageName, ip);

}

catch (PackageManager.NameNotFoundException e)

{

// shouldn't happen

e.printStackTrace();

}

}

}

return iconPacks;

}

}