android – Listview和CustomAdapter扩展SimpleCursorAdapter

Android 2020-04-22

我希望操纵ListView中所选行的背景颜色,从阅读中我需要使用CustomAdapter进行扩展.我的主适配器是SimpleCursorAdapter类型,所以我修改了一个将ArrayAdapter扩展为SimpleCursorAdapter的CustomAdapter.

我的问题是使用CustomAdapter时listview是空白但如果不扩展并使用SimpleCursorAdapter,listview有行/项.
Logcat在我的CustomAdapter中显示一个问题,见下文.

这是我的主要活动代码：

phrasesdb helper = new phrasesdb(this);
database = helper.getWritableDatabase();
data = database.query("phrases",fields,null,fields[0] + " COLLATE NOCASE ASC");
//WORKING SimpleCursorAdapter
//dataSource = new SimpleCursorAdapter(this,R.layout.phrases,data,new int[] { R.id.phrase });

//NOT WORKING
dataSource = new CustomAdapter(this,new int[] { R.id.phrase });

view = getListView();
setListAdapter(dataSource);

这是Custom Adapter类,我已经标记了logcat错误的位置：

import android.content.Context;
import android.database.Cursor;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.SimpleCursorAdapter;
import android.widget.TextView;

public class CustomAdapter extends SimpleCursorAdapter {

protected static final int NO_SELECTED_COLOR = 0xFF191919;
protected static final int SELECTED_COLOR = 0xFF3366CC;

Cursor items;
private LayoutInflater mInflater;
private int viewResourceId;
private int selectedPosition;


public CustomAdapter(Context context,int resourceId,Cursor data,String[] fields,int[] is) {
    super(context,resourceId,is);
    mInflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    viewResourceId = resourceId;
    items = data;
}


@Override
public View getView(int position,View convertView,ViewGroup parent) {
    TextView tv = (TextView)convertView;
    if (tv == null) {
  //WHEN DEBUGGING THIS IS WHERE LOGCAT ERROR MESSAGES STARTS
        tv = (TextView)mInflater.inflate(viewResourceId,null);
    }
    tv.setText(items.getString(position));



    // Change the background color
    if (position==selectedPosition) tv.setBackgroundColor(SELECTED_COLOR);
    else tv.setBackgroundColor(NO_SELECTED_COLOR);

    return tv;
}

public void setSelected(int position) {
    selectedPosition = position;
}
}

这是LogCat：

10-18 13:33:17.869: E/ListView(28378): android.widget.LinearLayout
10-18 13:33:17.869: E/ListView(28378): java.lang.ClassCastException: android.widget.LinearLayout
10-18 13:33:17.869: E/ListView(28378): at com.xxx.xxx.CustomAdapter.getView(CustomAdapter.java:49)
10-18 13:33:17.869: E/ListView(28378): at android.widget.AbsListView.obtainView(AbsListView.java:1449)
10-18 13:33:17.869: E/ListView(28378): at android.widget.ListView.makeAndAddView(ListView.java:1801)
10-18 13:33:17.869: E/ListView(28378): at android.widget.ListView.fillSpecific(ListView.java:1339)
10-18 13:33:17.869: E/ListView(28378): at android.widget.ListView.layoutChildren(ListView.java:1637)
10-18 13:33:17.869: E/ListView(28378): at android.widget.AbsListView.onLayout(AbsListView.java:1279)
10-18 13:33:17.869: E/ListView(28378): at android.view.View.layout(View.java:7321)
10-18 13:33:17.869: E/ListView(28378): at android.widget.FrameLayout.onLayout(FrameLayout.java:338)
10-18 13:33:17.869: E/ListView(28378): at android.view.View.layout(View.java:7321)
10-18 13:33:17.869: E/ListView(28378): at android.widget.FrameLayout.onLayout(FrameLayout.java:338)
10-18 13:33:17.869: E/ListView(28378): at android.view.View.layout(View.java:7321)
10-18 13:33:17.869: E/ListView(28378): at android.view.ViewRoot.performTraversals(ViewRoot.java:1217)
10-18 13:33:17.869: E/ListView(28378): at android.view.ViewRoot.handleMessage(ViewRoot.java:1991)
10-18 13:33:17.869: E/ListView(28378): at android.os.Handler.dispatchMessage(Handler.java:99)
10-18 13:33:17.869: E/ListView(28378): at android.os.Looper.loop(Looper.java:150)
10-18 13:33:17.869: E/ListView(28378): at android.app.ActivityThread.main(ActivityThread.java:4385)
10-18 13:33:17.869: E/ListView(28378): at java.lang.reflect.Method.invokeNative(Native Method)
10-18 13:33:17.869: E/ListView(28378): at java.lang.reflect.Method.invoke(Method.java:507)
10-18 13:33:17.869: E/ListView(28378): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:849)
10-18 13:33:17.869: E/ListView(28378): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:607)
10-18 13:33:17.869: E/ListView(28378): at dalvik.system.NativeStart.main(Native Method)

这是布局

Logcat表示与LinearLayout有关,但我无法弄清楚我哪里出错了.

请任何人能够朝着正确的方向发展我吗？

谢谢
标记

更新：根据Sardor的想法(谢谢你)更改为匹配膨胀之后：

tv = (TextView)mInflater.inflate(viewResourceId,parent);

我现在得到这个错误

10-18 15:23:22.083: E/ListView(28931): addView(View,LayoutParams) is not supported in AdapterView
10-18 15:23:22.083: E/ListView(28931): java.lang.UnsupportedOperationException: addView(View,LayoutParams) is not supported in AdapterView
10-18 15:23:22.083: E/ListView(28931):  at android.widget.AdapterView.addView(AdapterView.java:461)
10-18 15:23:22.083: E/ListView(28931):  at android.view.LayoutInflater.inflate(LayoutInflater.java:416)
10-18 15:23:22.083: E/ListView(28931):  at android.view.LayoutInflater.inflate(LayoutInflater.java:320)
10-18 15:23:22.083: E/ListView(28931):  at android.view.LayoutInflater.inflate(LayoutInflater.java:276)
10-18 15:23:22.083: E/ListView(28931):  at com.xxx.xxx.CustomAdapter.getView(CustomAdapter.java:36)
10-18 15:23:22.083: E/ListView(28931):  at android.widget.AbsListView.obtainView(AbsListView.java:1449)
10-18 15:23:22.083: E/ListView(28931):  at android.widget.ListView.makeAndAddView(ListView.java:1801)
10-18 15:23:22.083: E/ListView(28931):  at android.widget.ListView.fillSpecific(ListView.java:1339)
10-18 15:23:22.083: E/ListView(28931):  at android.widget.ListView.layoutChildren(ListView.java:1637)
10-18 15:23:22.083: E/ListView(28931):  at android.widget.AbsListView.onLayout(AbsListView.java:1279)
10-18 15:23:22.083: E/ListView(28931):  at android.view.View.layout(View.java:7321)
10-18 15:23:22.083: E/ListView(28931):  at android.widget.FrameLayout.onLayout(FrameLayout.java:338)
10-18 15:23:22.083: E/ListView(28931):  at android.view.View.layout(View.java:7321)
10-18 15:23:22.083: E/ListView(28931):  at android.widget.FrameLayout.onLayout(FrameLayout.java:338)
10-18 15:23:22.083: E/ListView(28931):  at android.view.View.layout(View.java:7321)
10-18 15:23:22.083: E/ListView(28931):  at android.view.ViewRoot.performTraversals(ViewRoot.java:1217)
10-18 15:23:22.083: E/ListView(28931):  at android.view.ViewRoot.handleMessage(ViewRoot.java:1991)
10-18 15:23:22.083: E/ListView(28931):  at android.os.Handler.dispatchMessage(Handler.java:99)
10-18 15:23:22.083: E/ListView(28931):  at android.os.Looper.loop(Looper.java:150)
10-18 15:23:22.083: E/ListView(28931):  at android.app.ActivityThread.main(ActivityThread.java:4385)
10-18 15:23:22.083: E/ListView(28931):  at java.lang.reflect.Method.invokeNative(Native Method)
10-18 15:23:22.083: E/ListView(28931):  at java.lang.reflect.Method.invoke(Method.java:507)
10-18 15:23:22.083: E/ListView(28931):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:849)
10-18 15:23:22.083: E/ListView(28931):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:607)
10-18 15:23:22.083: E/ListView(28931):  at dalvik.system.NativeStart.main(Native Method)
10-18 15:23:22.093: D/View(28931): onTouchEvent: viewFlags: 0x18244001

检查父级时,它正在查看TextView.

还有其他想法吗？

最佳答案
好吧,我终于开始工作……

这里的问题是,如果您的自定义适配器数据来自Cursor,那么您必须在扩展的SimpleCursorAdapter类中使用bindView和newView而不是getView.

我会为可能遇到此问题的其他人发布我的工作代码…

public class CustomAdapter extends SimpleCursorAdapter {

private int mSelectedPosition;
Cursor items;
private Context context;
private int layout;

@Override
public View newView(Context context,Cursor cursor,ViewGroup parent) {

    Cursor c = getCursor();

    final LayoutInflater inflater = LayoutInflater.from(context);
    View v = inflater.inflate(layout,parent,false);

    int nameCol = c.getColumnIndex("phrase");
    String name = c.getString(nameCol);

    TextView name_text = (TextView) v.findViewById(R.id.phrase);
    if (name_text != null) {
        name_text.setText(name);
    }
    return v;
}


public CustomAdapter(Context context,int layout,Cursor c,String[] from,int[] to) {
    super(context,layout,c,from,to);
    this.context = context;
    this.layout = layout;
}


@Override
public void bindView(View v,Context context,Cursor c) {

    int nameCol = c.getColumnIndex("phrase");
    String name = c.getString(nameCol);


    TextView name_text = (TextView) v.findViewById(R.id.phrase);
    if (name_text != null) {
        name_text.setText(name);
    }

    //name_text.setTextColor(Color.GREEN);

    int position = c.getPosition(); 
    if (mSelectedPosition == position) {
       v.setBackgroundResource(R.drawable.listviewbackground);
       v.getBackground().setDither(true);
    } else {
       v.setBackgroundColor(Color.BLACK);
    }

}


public void setSelectedPosition(int position) {
    mSelectedPosition = position;
    notifyDataSetChanged();

}

和

  Cursor data;
  static final String fields[] = { "phrase",BaseColumns._ID };

  dataSource = new CustomAdapter(this,new int[] { R.id.phrase });
  view = getListView();
  setListAdapter(dataSource);
androidandroid

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