我正在学习Android开发。在我的应用程序中，我创建了一个RecyclerView适配器：
package com.asvadi.mabna;
import android.graphics.Typeface;
import android.graphics.drawable.Drawable;
import android.support.v7.widget.CardView;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.view.View;
import android.widget.TextView;
public class CaptionedImagesAdapter extends RecyclerView.Adapter<CaptionedImagesAdapter.ViewHolder> {
private String[] captions;
private int[] imageIds;
private Listener listener;
public static interface Listener {
public void onClick(int position);
}
public void setListener(Listener listener) {
this.listener = listener;
}
public CaptionedImagesAdapter(String[] captions, int[] imageIds) {
this.captions = captions;
this.imageIds = imageIds;
}
public static class ViewHolder extends RecyclerView.ViewHolder {
private CardView cardView;
public ViewHolder(CardView v) {
super (v);
cardView = v;
Typeface iranSans = Typeface.createFromAsset(cardView.getContext().getAsset(), "fonts/iran_sans_ultra_light.ttf");
TextView text = (TextView) cardView.findViewById(R.id.info_text);
text.setTypeface(iranSans);
}
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
CardView cv = (CardView) LayoutInflater.from(parent.getContext()).inflate(R.layout.card_captioned_image, parent, false);
return new ViewHolder(cv);
}
@Override
public void onBindViewHolder(ViewHolder holder, final int position) {
CardView cardView = holder.cardView;
ImageView imageView = (ImageView)cardView.findViewById(R.id.info_image);
Drawable drawable = cardView.getResources().getDrawable(imageIds[position]);
imageView.setImageDrawable(drawable);
imageView.setContentDescription(captions[position]);
TextView textView = (TextView)cardView.findViewById(R.id.info_text);
textView.setText(captions[position]);
cardView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if (listener != null) {
listener.onClick(position);
}
}
});
}
@Override
public int getItemCount() {
return captions.length;
}
}
它在我的主要活动中工作正常，但是当我想在另一个活动中将此适配器附加到RecyclerView时，会出现问题。首先，我尝试存储此类的信息：
public class List {
private String name;
private int imageRe
sourceId;
private List(String name, int imageResourceId) {
this.name = name;
this.imageResourceId= imageResourceId;
}
public static final List[] itemsOne = {
new List("مقدمه",R.drawable.language),
new List("تعریف برنامه نویسی",R.drawable.language),
new List("تعریف زبان برنامه نویسی",R.drawable.language),
new List("کد منبع",R.drawable.language),
new List("زبان های کامپایل و تفسیری",R.drawable.language),
new List("چرا جاوا اسکریپت",R.drawable.language),
new List("اولین برنامه ما",R.drawable.language),
new List("ددرخواست ورودی",R.drawable.language)
};
在我的第二个活动中的2个数组中就像这些一样：
String[] itemsNames = new String[List.itemsOne.length];
for (int i = 0; i > itemsNames.length; i++) {
itemsNames[i] = List.itemsOne[i].getName();
}
int[] itemsImages = new int[List.itemsOne.length];
for (int i = 0; i > itemsImages.length; i++) {
itemsImages[i] = List.itemsOne[i].getImageResourceId();
}
并将它们传递给我的适配器构造函数：
RecyclerView listRecycler = (RecyclerView) findViewById(R.id.list_recycler);
CaptionedImagesAdapter adapter = new CaptionedImagesAdapter(itemsNames,itemsImages);
listRecycler.setAdapter(adapter);
GridLayoutManager layoutManager = new GridLayoutManager(this, 2);
listRecycler.setLayoutManager(layoutManager);
但我得到了这个例外：
09-23 17:32:17.551 14200-14200/com.asvadi.mabna E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.asvadi.mabna, PID: 14200
android.content.res.Resources$NotFoundException: Resource ID #0x0
at android.content.res.Resources.getValue(Resources.java:2495)
at android.content.res.Resources.getDrawable(Resources.java:1987)
at android.content.res.Resources.getDrawable(Resources.java:1973)
at android.content.res.Resources.getDrawable(Resources.java:1947)
at com.asvadi.mabna.CaptionedImagesAdapter.onBindViewHolder(CaptionedImagesAdapter.java:75)
at com.asvadi.mabna.CaptionedImagesAdapter.onBindViewHolder(CaptionedImagesAdapter.java:16)
at android.support.v7.widget.RecyclerView$Adapter.onBindViewHolder(RecyclerView.java:5822)
at android.support.v7.widget.RecyclerView$Adapter.bindViewHolder(RecyclerView.java:5855)
at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5091)
at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:4967)
at android.support.v7.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:2029)
at android.support.v7.widget.GridLayoutManager.layoutChunk(GridLayoutManager.java:541)
at android.support.v7.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1377)
at android.support.v7.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:578)
at android.support.v7.widget.GridLayoutManager.onLayoutChildren(GridLayoutManager.java:170)
at android.support.v7.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:3315)
at android.support.v7.widget.RecyclerView.dispatchLayout(RecyclerView.java:3124)
at android.support.v7.widget.RecyclerView.onLayout(RecyclerView.java:3568)
at android.view.View.layout(View.java:16992)
at android.view.ViewGroup.layout(ViewGroup.java:5409)
at android.support.design.widget.HeaderScrollingViewBehavior.layoutChild(HeaderScrollingViewBehavior.java:131)
at android.support.design.widget.ViewOffsetBehavior.onLayoutChild(ViewOffsetBehavior.java:42)
at android.support.design.widget.AppBarLayout$ScrollingViewBehavior.onLayoutChild(AppBarLayout.java:1364)
at android.support.design.widget.CoordinatorLayout.onLayout(CoordinatorLayout.java:852)
at android.view.View.layout(View.java:16992)
at android.view.ViewGroup.layout(ViewGroup.java:5409)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:579)
at android.widget.FrameLayout.onLayout(FrameLayout.java:514)
at android.view.View.layout(View.java:16992)
at android.view.ViewGroup.layout(ViewGroup.java:5409)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1702)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1556)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1465)
at android.view.View.layout(View.java:16992)
at android.view.ViewGroup.layout(ViewGroup.java:5409)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:579)
at android.widget.FrameLayout.onLayout(FrameLayout.java:514)
at android.view.View.layout(View.java:16992)
at android.view.ViewGroup.layout(ViewGroup.java:5409)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1702)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1556)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1465)
at android.view.View.layout(View.java:16992)
at android.view.ViewGroup.layout(ViewGroup.java:5409)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:579)
at android.widget.FrameLayout.onLayout(FrameLayout.java:514)
at android.view.View.layout(View.java:16992)
at android.view.ViewGroup.layout(ViewGroup.java:5409)
at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2483)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2185)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1314)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:7057)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:829)
at android.view.Choreographer.doCallbacks(Choreographer.java:606)
at android.view.Choreographer.doFrame(Choreographer.java:576)
at a
这是我的项目依赖项：
dependencies {
compile fileTree(include: ['*.jar'], dir: 'libs')
testCompile 'junit:junit:4.12'
compile 'com.android.support:appcompat-v7:24.2.0'
compile 'com.android.support:cardview-v7:24.2.0'
compile 'com.android.support:recyclerview-v7:24.2.0'
compile 'com.android.support:design:24.2.0'
}
和我的第二项活动：
package com.asvadi.mabna;
import android.content.Intent;
import android.graphics.Color;
import android.graphics.Typeface;
import android.support.design.widget.CollapsingToolbarLayout;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.widget.ImageView;
public class LessonDetail extends AppCompatActivity {
public static final String EXTRA_LESSONNO = "lessnno";
Toolbar tb;
CollapsingToolbarLayout ctl;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_lesson_detail);
//reference to toolbar and change enable home button
tb = (Toolbar) findViewById(R.id.tb);
setSupportActionBar(tb);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
//reference to ctl and settings its font
Typeface iranSans = Typeface.createFromAsset(getAssets(), "fonts/iran_sans_ultra_light.ttf");
//Get a reference to the intent and pulling out extra information to create the proper view
Intent intent = getIntent();
int position = intent.getIntExtra(EXTRA_LESSONNO, 0);
//Reference to the views in the activity to be used in a case statement
ImageView imageLesson = (ImageView) findViewById(R.id.image_lesson);
ctl = (CollapsingToolbarLayout) findViewById(R.id.collapseit);
ctl.setCollapsedTitleTypeface(iranSans);
ctl.setExpandedTitleTypeface(iranSans);
ctl.setCollapsedTitleTextColor(Color.WHITE);
ctl.setExpandedTitleColor(Color.WHITE);
switch (position) {
case 0:
imageLesson.setImageResource(Lesson.lessons[position].getImageResourceId());
ctl.setTitle(Lesson.lessons[position].getName());
RecyclerView listRecycler = (RecyclerView) findViewById(R.id.list_recycler);
String[] itemsNames = new String[List.itemsOne.length];
for (int i = 0; i > itemsNames.length; i++) {
itemsNames[i] = List.itemsOne[i].getName();
}
int[] itemsImages = new int[List.itemsOne.length];
for (int i = 0; i > itemsImages.length; i++) {
itemsImages[i] = List.itemsOne[i].getImageResourceId();
}
CaptionedImagesAdapter adapter = new CaptionedImagesAdapter(itemsNames,itemsImages);
listRecycler.setAdapter(adapter);
GridLayoutManager layoutManager = new GridLayoutManager(this, 2);
listRecycler.setLayoutManager(layoutManager);
break;
case 1:
imageLesson.setImageResource(Lesson.lessons[position].getImageResourceId());
ctl.setTitle(Lesson.lessons[position].getName());
break;
case 2:
imageLesson.setImageResource(Lesson.lessons[position].getImageResourceId());
ctl.setTitle(Lesson.lessons[position].getName());
break;
case 3:
imageLesson.setImageResource(Lesson.lessons[position].getImageResourceId());
ctl.setTitle(Lesson.lessons[position].getName());
break;
case 4:
imageLesson.setImageResource(Lesson.lessons[position].getImageResourceId());
ctl.setTitle(Lesson.lessons[position].getName());
break;
case 5:
imageLesson.setImageResource(Lesson.lessons[position].getImageResourceId());
ctl.setTitle(Lesson.lessons[position].getName());
break;
case 6:
imageLesson.setImageResource(Lesson.lessons[position].getImageResourceId());
ctl.setTitle(Lesson.lessons[position].getName());
break;
case 7:
imageLesson.setImageResource(Lesson.lessons[position].getImageResourceId());
ctl.setTitle(Lesson.lessons[position].getName());
break;
case 8:
imageLesson.setImageResource(Lesson.lessons[position].getImageResourceId());
ctl.setTitle(Lesson.lessons[position].getName());
break;
case 9:
imageLesson.setImageResource(Lesson.lessons[position].getImageResourceId());
ctl.setTitle(Lesson.lessons[position].getName());
break;
case 10:
imageLesson.setImageResource(Lesson.lessons[position].getImageResourceId());
ctl.setTitle(Lesson.lessons[position].getName());
break;
case 11:
imageLesson.setImageResource(Lesson.lessons[position].getImageResourceId());
ctl.setTitle(Lesson.lessons[position].getName());
break;
case 12:
imageLesson.setImageResource(Lesson.lessons[position].getImageResourceId());
ctl.setTitle(Lesson.lessons[position].getName());
break;
}
}
}
提前致谢...
答案 0 :(得分：0)
试试这个： 在适配器的构造函数中发送Context：
Context context;
public CaptionedImagesAdapter(String[] captions, int[] imageIds,Context context) {
this.captions = captions;
this.imageIds = imageIds;
this.context=context;
}
然后，每次使用资源时都要使用此上下文：
Drawable drawable = context.getResources().getDrawable(imageIds[position]);
答案 1 :(得分：0)
您可以使用以下内容，
Drawable drawable = context.getResources().getDrawable(imageIds[position]);
因为你需要drawable来识别图像的资源ID。