我想在自定义适配器工作中获取我的复选框。但是，仍然有一小部分我没有得到，我的程序不断关闭每种类型，我试图测试它。
这是一个文件管理器，列出了SD卡中的所有图像文件。
public class FileBrowserMusic extends ListActivity {
private File currentDir;
private FileArrayAdapter adapter;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.music_main);
currentDir = new File (Environment.getExternalStorageDirectory().getPath());
List<Option>flss = new ArrayList<Option>();
listFiles (currentDir, flss);
Collections.sort (flss);
ArrayAdapter<Option> adapter = new FileArrayAdapter(this, flss);
setListAdapter(adapter);
registerForContextMenu(getListView());
}
// Recursively search for all image files.
private void listFiles (File f, List<Option> flss) {
if(f.isDirectory()){
File[] files = f.listFiles();
try {
for (File ff : files){
if(!ff.isDirectory()) {
if(ff.getName().endsWith(".jpg")) {
Log.d(" FILES",ff.getName());
flss.add(new Option (ff.getName(),"Files Size: "+ff.length(),ff.getAbsolutePath()));
}
}
else {
listFiles(ff, flss);
}
}
} catch (Exception e) {
// TODO Auto-generated catch block
//e.printStackTrace();
}
}
}
}
这是我的适配器类。
public class FileArrayAdapter extends ArrayAdapter<Option> {
private Context c;
private int id;
private List<Option>items;
private Activity context;
public FileArrayAdapter(Activity context, List<Option> objects) {
super(context, R.layout.music_view, objects);
this.context = context;
items = objects;
}
public Option getItem (int i) {
return items.get (i);
}
static class ViewHolder {
protected TextView name, size;
protected CheckBox checkbox;
}
@Override
public View getView (int position, View convertView, ViewGroup parent) {
// View v = convertView;
final Option o = items.get(position);
/*if (v == null) {
LayoutInflater vi = (LayoutInflater)c.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
v = vi.inflate(R.layout.music_view, null);*/
View v = null;
final ViewHolder viewHolder = new ViewHolder();
if (convertView == null) {
LayoutInflater inflator = context.getLayoutInflater();
v = inflator.inflate(R.layout.music_view, null);
//TextView t1 = (TextView) v.findViewById(R.id.backDot);
//TextView t2 = (TextView) v.findViewById(R.id.backPDir);
viewHolder.name = (TextView) v.findViewById(R.id.name);
viewHolder.size = (TextView) v.findViewById(R.id.size);
viewHolder.checkbox = (CheckBox) v.findViewById(R.id.check);
viewHolder.checkbox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
// TODO Auto-generated method stub
Option element = (Option) viewHolder.checkbox.getTag();
element.setSelected(buttonView.isChecked());
Log.v("Checked : ", ""+ element.getName());
}
});
v.setTag(viewHolder);
viewHolder.checkbox.setTag(items.get(position));
} else {
v = convertView;
((ViewHolder) v.getTag()).checkbox.setTag(items.get(position));
}
ViewHolder holder = (ViewHolder) v.getTag();
holder.name.setText(o.getName());
holder.size.setText(o.getPath());
holder.checkbox.setChecked(o.isSelected());
return v;
}
}
我的选项类。
public class Option implements Comparable<Option>{
private String name;
private String data;
private String path;
boolean selected = false;
public Option (String n, String d, String p) {
name = n;
data = d;
path = p;
}
public Option (String n, String d, String p, boolean s) {
name = n;
data = d;
path = p;
selected = s;
}
public void setName (String n) {
name = n;
}
public void setData (String d) {
data = d;
}
public void setPath (String p) {
path = p;
}
public String getName() {
return name;
}
public String getData() {
return data;
}
public String getPath() {
return path;
}
public boolean isSelected() {
return selected;
}
public void setSelected (boolean s) {
this.selected = s;
}
public int compareTo(Option o) {
if (this.name != null) {
return this.name.toLowerCase().compareTo(o.getName().toLowerCase());
} else {
throw new IllegalArgumentException();
}
}
}
最后，我的XML。
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent" android:layout_height="wrap_content">
<TextView android:text="@+id/name" android:layout_width="wrap_content"
android:layout_height="wrap_content" android:id="@+id/label"
android:layout_marginLeft="15dp"
android:layout_marginTop="5dp"
android:textStyle="bold"
android:textSize="20sp"></TextView>
<TextView android:text="@+id/size"
android:layout_below="@+id/label"
android:layout_width="wrap_content"
android:layout_height="wrap_content" android:id="@+id/sub"
android:layout_marginLeft="15dp"
android:textSize="15sp"></TextView>
<CheckBox android:id="@+id/check" android:layout_width="wrap_content"
android:layout_height="wrap_content" android:layout_marginLeft="4dp"
android:layout_marginRight="10dp" android:layout_alignParentRight="true"
></CheckBox>
</RelativeLayout>
我哪里出错了？最初，我的代码仅用于列出listview中的图像文件。之后，我试图实现复选框但无法实现。
欣赏它。
由于所有的测试和内容，代码现在非常混乱。
T1和T2是我以前执行文件管理器时的代码。可以忽略它，不应该乱用我当前的代码我猜。我会将其删除并进行测试。
这是我的日志。
03-29 18:37:56.086: E/AndroidRuntime(4299): FATAL EXCEPTION: main
03-29 18:37:56.086: E/AndroidRuntime(4299): java.lang.NullPointerException
03-29 18:37:56.086: E/AndroidRuntime(4299): at sg.joogle.safeit.FileArrayAdapter.getView(FileArrayAdapter.java:98)
03-29 18:37:56.086: E/AndroidRuntime(4299): at android.widget.AbsListView.obtainView(AbsListView.java:2033)
03-29 18:37:56.086: E/AndroidRuntime(4299): at android.widget.ListView.measureHeightOfChildren(ListView.java:1244)
03-29 18:37:56.086: E/AndroidRuntime(4299): at android.widget.ListView.onMeasure(ListView.java:1155)
03-29 18:37:56.086: E/AndroidRuntime(4299): at android.view.View.measure(View.java:12723)
03-29 18:37:56.086: E/AndroidRuntime(4299): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4698)
03-29 18:37:56.086: E/AndroidRuntime(4299): at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1369)
03-29 18:37:56.086: E/AndroidRuntime(4299): at android.widget.LinearLayout.measureVertical(LinearLayout.java:660)
03-29 18:37:56.086: E/AndroidRuntime(4299): at android.widget.LinearLayout.onMeasure(LinearLayout.java:553)
03-29 18:37:56.086: E/AndroidRuntime(4299): at android.view.View.measure(View.java:12723)
03-29 18:37:56.086: E/AndroidRuntime(4299): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4698)
03-29 18:37:56.086: E/AndroidRuntime(4299): at android.widget.FrameLayout.onMeasure(FrameLayout.java:293)
03-29 18:37:56.086: E/AndroidRuntime(4299): at android.view.View.measure(View.java:12723)
03-29 18:37:56.086: E/AndroidRuntime(4299): at android.widget.LinearLayout.measureVertical(LinearLayout.java:812)
03-29 18:37:56.086: E/AndroidRuntime(4299): at android.widget.LinearLayout.onMeasure(LinearLayout.java:553)
03-29 18:37:56.086: E/AndroidRuntime(4299): at android.view.View.measure(View.java:12723)
03-29 18:37:56.086: E/AndroidRuntime(4299): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4698)
03-29 18:37:56.086: E/AndroidRuntime(4299): at android.widget.FrameLayout.onMeasure(FrameLayout.java:293)
03-29 18:37:56.086: E/AndroidRuntime(4299): at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2092)
03-29 18:37:56.086: E/AndroidRuntime(4299): at android.view.View.measure(View.java:12723)
03-29 18:37:56.086: E/AndroidRuntime(4299): at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1064)
03-29 18:37:56.086: E/AndroidRuntime(4299): at android.view.ViewRootImpl.handleMessage(ViewRootImpl.java:2442)
03-29 18:37:56.086: E/AndroidRuntime(4299): at android.os.Handler.dispatchMessage(Handler.java:99)
03-29 18:37:56.086: E/AndroidRuntime(4299): at android.os.Looper.loop(Looper.java:137)
03-29 18:37:56.086: E/AndroidRuntime(4299): at android.app.ActivityThread.main(ActivityThread.java:4424)
03-29 18:37:56.086: E/AndroidRuntime(4299): at java.lang.reflect.Method.invokeNative(Native Method)
03-29 18:37:56.086: E/AndroidRuntime(4299): at java.lang.reflect.Method.invoke(Method.java:511)
03-29 18:37:56.086: E/AndroidRuntime(4299): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
03-29 18:37:56.086: E/AndroidRuntime(4299): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
03-29 18:37:56.086: E/AndroidRuntime(4299): at dalvik.system.NativeStart.main(Native Method)
答案 0 :(得分：0)
你检查o！ - null，但是在那个if块之外你分配了setText 使用o.getName。那个时候o真的可能是空的吗？