我想从数据库“listOfFolder”表“文件夹”访问所有的数据,并希望将数据存储在字符串数组文件夹[]但我得到如何解决ArrayIndexOutOfBoundsException。如何解决ArrayIndexOutOfBoundsException
try{
mydb = openOrCreateDatabase("listOfFolder", MODE_WORLD_WRITEABLE, null);
} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
int count = 0;
String folders[] = null;
Cursor folderCursor = mydb.query("folder", null, null, null, null, null, null);
while(folderCursor.moveToNext()) {
folders[count] = folderCursor.getString(folderCursor.getColumnIndex("name"));
count++;
}
ListView list = (ListView)findViewById(R.id.lv);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(DropboxActivity.this, android.R.layout.simple_list_item_1,folders);
list.setAdapter(adapter);
setContentView(R.layout.listoffolder);
之后,我想创建一个列表视图,再次我得到nullpointerexception那里ListView list =(ListView)findViewById(R.id.lv); \t \t \t ArrayAdapter adapter = new ArrayAdapter (DropboxActivity.this,android.R.layout.simple_list_item_1,folders); \t \t \t list.setAdapter(adapter); \t \t \t setContentView(R.layout.listoffolder); –
sachin
获得空指针异常在 \t \t \t list.setAdapter(adapter); – sachin
可能'findViewById'找不到您的ListView。你确定在布局xml文件中有一个ID为“@ + id/lv”的ListView吗? – vasart