因此,我一直在搜寻昨天和最后一个夜晚的大部分时间,似乎似乎无法绕过如何将arraylist传递给子 Activity 的想法。有大量传递基本数据类型的示例和摘要,但是我所拥有的是地址类型的数组列表(下面的address.java)。
我在stackoverflow和网络上发现了很多东西,但是除了带有GeoPoint示例的东西之外,没有其他东西引起很多关注。再一次,在我看来,他们只是将GeoPoint对象展平为两个整数并将其传递。我无法这样做,因为我的地址类可能会扩展为包括整数,浮点数或其他任何内容。现在,为了简单起见,下面的测试应用程序只有两个字符串。我以为,如果我可以让parcelalbe的东西可以工作的话,剩下的事就可以了。
有人可以为非原始对象的ArrayList发布工作示例,还是可以在下面添加代码以使工作正常?
更新:答复/编辑后,下面的代码现在可以工作。谢谢!
/* helloParcel.java */
public class helloParcel extends Activity
{
// holds objects of type 'address' == name and state
private ArrayList <address> myList;
@Override
public void onCreate (Bundle savedInstanceState)
{
super.onCreate (savedInstanceState);
setContentView (R.layout.main);
Button b1 = (Button) findViewById(R.id.button1);
b1.setOnClickListener(ocl);
myList = new ArrayList();
address frank = new address ("frank", "florida");
address mary = new address ("mary", "maryland");
address monty = new address ("monty", "montana");
myList.add (frank);
myList.add (mary);
myList.add (monty);
// add the myList ArrayList() the the extras for the intent
}
OnClickListener ocl = new OnClickListener()
{
@Override
public void onClick(View v)
{
// fill parceable and launch activity
Intent intent = new Intent().setClass(getBaseContext (), subActivity.class);
// for some reason, I remember a posting saying it's best to create a new
// object to pass. I have no idea why..
ArrayList <address> addyExtras = new ArrayList <address>();
for (int i = 0; i < myList.size(); i++)
addyExtras.add (myList.get(i));
intent.putParcelableArrayListExtra ("mylist", addyExtras);
startActivity(intent);
}
};
}
/* address.java */
public class address implements Parcelable
{
private String name;
private String state;
private static String TAG = "** address **";
public address (String n, String s)
{
name = n;
state = s;
Log.d (TAG, "new address");
}
public address (Parcel in)
{
Log.d (TAG, "parcel in");
name = in.readString ();
state = in.readString ();
}
public String getState ()
{
Log.d (TAG, "getState()");
return (state);
}
public String getName ()
{
Log.d (TAG, "getName()");
return (name);
}
public static final Parcelable.Creator<address> CREATOR
= new Parcelable.Creator<address>()
{
public address createFromParcel(Parcel in)
{
Log.d (TAG, "createFromParcel()");
return new address(in);
}
public address[] newArray (int size)
{
Log.d (TAG, "createFromParcel() newArray ");
return new address[size];
}
};
@Override
public int describeContents ()
{
Log.d (TAG, "describe()");
return 0;
}
@Override
public void writeToParcel (Parcel dest, int flags)
{
Log.d (TAG, "writeToParcel");
dest.writeString (name);
dest.writeString (state);
}
}
/* subActivity.java */
public class subActivity extends Activity
{
private final String TAG = "** subActivity **";
private ArrayList <address> myList;
@Override
protected void onCreate (Bundle savedInstanceState)
{
super.onCreate (savedInstanceState);
Log.d (TAG, "onCreate() in subActivity");
setContentView(R.layout.subactivity);
TextView tv1 = (TextView) findViewById(R.id.tv_sub);
myList = getIntent().getParcelableArrayListExtra ("mylist");
Log.d (TAG, "got myList");
for (int i = 0; i < myList.size (); i++)
{
address a = myList.get (i);
Log.d (TAG, "state:" + a.getState ());
tv1.setText (a.getName () + " is from " + a.getState ());
}
}
}
最佳答案
我可以在这里看到许多问题:
intent.putParcelableArrayListExtra( "addresses", addyExtras );
startActivity()
之前,您实际上并未在意图中添加任何其他功能。有关建议,请参见第1点。 我认为您需要解决所有这些问题才能使其正常运行。
关于android - 帮助传递ArrayList和parcelable Activity,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/5819238/