I am trying to list all the music files on the SD card using List view. And in the Java code for the Activity , I get an error, Here is the method I use in class:
我正在尝试使用列表视图列出SD卡上的所有音乐文件。在Activity的Java代码中,我收到一个错误,这是我在课堂上使用的方法:
private void init_phone_music_grid() {
System.gc();
String[] proj = { MediaStore.Audio.Media._ID,
MediaStore.Audio.Media.DATA,
MediaStore.Audio.Media.DISPLAY_NAME,
MediaStore.Video.Media.SIZE };
musiccursor =
managedQuery(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,
proj, null, null, null);
count = musiccursor.getCount();
musiclist = (ListView)findViewById(R.id.sample);
musiclist.setAdapter(new MusicAdapter(getApplicationContext()));
musiclist.setOnItemClickListener(musicgridlistener);
mMediaPlayer = new MediaPlayer();
}
Now here is the simple trouble,
现在这是一个简单的麻烦,
musiclist = (ListView)findViewById(R.id.sample);
Android Studio Says cannot resolve symbol sample
.
Android Studio说无法解析符号示例。
But how is that possible when I ve clearly defined that in XML? Here is the XML code:
但是,当我在XML中明确定义时,这怎么可能呢?这是XML代码:
<?xml version="1.0" encoding="utf-8"?>
< LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="fill_parent"
android:layout_height="fill_parent">
< ListView
android:id="@+id/sample"
android:layout_width="fill_parent"
android:layout_height="fill_parent"/>
</LinearLayout>
Looking for a solution !
寻找解决方案!
1 个解决方案
#1
5
Not sure if it will fix the problem but your xml is malformed.
不确定它是否能解决问题,但你的xml格式不正确。
There shouldn't be any spaces after the <
sign:
<符号后面不应该有任何空格:< p>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="fill_parent"
android:layout_height="fill_parent">
<ListView
android:id="@+id/sample"
android:layout_width="fill_parent"
android:layout_height="fill_parent"/>
#1
5
Not sure if it will fix the problem but your xml is malformed.
不确定它是否能解决问题,但你的xml格式不正确。
There shouldn't be any spaces after the <
sign:
<符号后面不应该有任何空格:< p>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="fill_parent"
android:layout_height="fill_parent">
<ListView
android:id="@+id/sample"
android:layout_width="fill_parent"
android:layout_height="fill_parent"/>