public class MusicListDataAdapter extends BaseAdapter {
private LayoutInflater mInflater;
private ViewHolder holder;
private ArrayList<FileData> musicList;

public MusicListDataAdapter(Context context,ArrayList<FileData> dataList) {
    mInflater = LayoutInflater.from(context);
    musicList = dataList;
}

@Override
public int getCount() {
    return musicList == null ? 0 : musicList.size();
}

@Override
public Object getItem(int position) {
    return musicList == null ? 0 : musicList.get(position);
}

@Override
public long getItemId(int position) {
    return position;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    if (convertView == null) {
        //这里就是能解决问题的地方，，然后在xml中设置具体的宽度：200dp这种
        convertView = mInflater.inflate(R.layout.music_list_data_item,parent,false);

        holder = new ViewHolder();
        holder.txtName = (TextView) convertView.findViewById(R.id.txt_musicName);
        convertView.setTag(holder);
    } else {
        holder.txtName = (TextView) convertView.findViewById(R.id.txt_musicName);
    }
    holder.txtName.setText(musicList.get(position).getTilte());
    return convertView;
}

class ViewHolder {
    TextView txtName;
}

}

music_list_data_item.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="300dp"
android:layout_height="30dp"
android:gravity="center_vertical"
android:orientation="horizontal"
>

<ImageView
   android:id="@+id/leftImageView"
   android:layout_width="20dip"
   android:layout_height="20dip"
   android:layout_marginLeft="5dip"
   android:src="@drawable/icon_file_song" />

<TextView
   android:id="@+id/txt_musicName"
   android:layout_width="match_parent"
   android:layout_height="wrap_content"
   android:layout_marginLeft="10dip"
   android:singleLine="true"
   android:textColor="@android:color/darker_gray"
   android:textSize="15sp" />

</LinearLayout>

其他类

public class FileData {

String tilte;
String path;
int icon;
String author;
String singer;

public String getTilte() {
    return tilte;
}
public void setTilte(String tilte) {
    this.tilte = tilte;
}

public String getPath() {
    return path;
}
public void setPath(String path) {
    this.path = path;
}

public int getIcon() {
    return icon;
}
public void setIcon(int icon) {
    this.icon = icon;
}

public String getAuthor() {
    return author;
}
public void setAuthor(String author) {
    this.author = author;
}

public String getSinger() {
    return singer;
}
public void setSinger(String singer) {
    this.singer = singer;
}
}