Question

问题：

在滚动列表视图时，有时即使光标没有变化，也不会显示某些列表项的字段，即列表项呈现但不显示textview3 / statusIcon。
当我点击某个项目并再次查询内容提供程序时，会出现同样的问题。然后在Customadapter中更改获取的光标。

如果需要更多信息，请告知我们，我们会更新问题。

情景：

使用activity方法content provider查询数据库的onResume。
然后将结果cursor传递给CustomCursorAdapter。然后将此适配器传递给listview。列表更像是文件目录列表。对于某些项目，单击时应再次查询数据库并更改更新的光标以再次呈现UI。
“列出”项目在大多数时间内将数据呈现为已编程。

listeitem.xml如下： -

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <TextView
        android:id="@+id/TextView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/TextView3"
        android:layout_below="@+id/TextView3"
        android:text="fileSize" />

    <ImageView
        android:id="@+id/itemIcon"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginLeft="37dp"
        android:layout_marginTop="25dp"
        android:contentDescription="file Icon"
        android:src="@drawable/ic_launcher" />

    <TextView
        android:id="@+id/TextView3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignTop="@+id/itemIcon"
        android:layout_marginLeft="37dp"
        android:layout_toRightOf="@+id/itemIcon"
        android:text="FileName"
        android:textAppearance="?android:attr/textAppearanceMedium" />

    <ImageView
        android:id="@+id/statusIcon"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:layout_alignTop="@+id/TextView3"
        android:layout_marginRight="21dp"
        android:src="@drawable/downloaded" />

</RelativeLayout>

调用以下方法从DB获取Cursor。另外注释，目前这个方法直接在UI线程上调用。

public Cursor getlistFromDB() {

    ContentResolver cr = getContentResolver();
        Cursor dataCursor = cr.query(CONTENT_URI, projections,
                selection, selectionArguments, null);
    return dataCursor ;
}

CustomListDBAdapter.java

import android.content.Context;
import android.database.Cursor;
import android.support.v4.widget.SimpleCursorAdapter;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;


public class CustomListDBAdapter extends SimpleCursorAdapter {

    private final String tag = "CustomListDBAdapter";
    private int layout;

    public CustomListDBAdapter(Context context, int layout, Cursor c,
            String[] from, int[] to, int flags) {
        super(context, layout, c, from, to, flags);
        Log.d(tag, "constructor 1");
        this.layout = layout;
    }

    public CustomListDBAdapter(Context context, int layout, Cursor c,
            String[] from, int[] to) {
        super(context, layout, c, from, to);
        System.out.println(" cursor count ");
        this.layout = layout;
    }

    @Override
    public View newView(Context context, Cursor cursor, ViewGroup parent) {
        Log.d(tag, " in newView");
        final LayoutInflater inflater = LayoutInflater.from(context);
        View v = inflater.inflate(layout, parent, false);
        return v;
    }

    @Override
    public void bindView(View v, Context context, Cursor c) {
        Log.d(tag, " in bindView");
        //get the column numbers using column name
        int column1 = c.getColumnIndex(TableMetaData.column1);
        int column2 = c.getColumnIndex(TableMetaData.column2);
        int column3 = c.getColumnIndex(TableMetaData.column3);
        int column4 = c.getInt(c.getColumnIndex(TableMetaData.column4));

        //get the column data using the column number
        String column1_Text = c.getString(column1);
        int column2_Type = c.getInt(column2);
        long column3_data = c.getLong(column3);

        //Setting data to the UI components
        TextView column1_TextTxt = (TextView)v.findViewById(R.id.TextView1);
        column1_TextTxt.setText(column1_Text);




        ImageView itemIcon = (ImageView)v.findViewById(R.id.itemIcon);
        //getImageResourceID is a method to get correct image according to column2_Type
        itemIcon.setImageResource(getImageResourceID(column2_Type));

        TextView textView3 = (TextView)v.findViewById(R.id.TextView3);
        ImageView downloadStatusIcon = (ImageView)v.findViewById(R.id.statusIcon);

        switch(column2_Type){
        case FileListTableMetaData.filetype_dir:

            textView3.setVisibility(View.GONE);
            downloadStatusIcon.setVisibility(View.GONE);
            break;

        default:

            textView3.setText("Test");
            downloadStatusIcon.setImageResource(R.drawable.image1);

        }

    }


}

ListView项目字段在渲染时显示不一致的行为

0 个答案: