Java 无法将ParseFile强制转换为android
我已经创建了一个概要文件创建页面，用户在其中填写各种信息，这些信息被记录到parse中。在此活动页面中，将检索来自解析的信息列表，如列表中许多用户（不包括当前用户）的年龄、姓名、标题和图片。然而，我在检索图像时遇到了一些问题。以下是我从logcat收到的错误：Java 无法将ParseFile强制转换为android,java,android,android-layout,android-activity,parse-platform,Java,Android,Android Layout,Android Activity,Parse Platform,我已经创建了一个概要文件创建页面，用户在其中填写各种信息，这些信息被记录到parse中。在此活动页面中，将检索来自解析的信息列表，如列表中许多用户（不包括当前用户）的年龄、姓名、标题和图片。然而，我在检索图像时遇到了一些问题。以下是我从logcat收到的错误： 08-16 21:53:16.401: E/AndroidRuntime(1345): FATAL EXCEPTION: main 08-16 21:53:16.401: E/AndroidRuntime(1345): Process:
08-16 21:53:16.401: E/AndroidRuntime(1345): FATAL EXCEPTION: main
08-16 21:53:16.401: E/AndroidRuntime(1345): Process: com.dooba.beta, PID: 1345
08-16 21:53:16.401: E/AndroidRuntime(1345): java.lang.ClassCastException: com.parse.ParseFile cannot be cast to android.provider.MediaStore$Images
08-16 21:53:16.401: E/AndroidRuntime(1345): at com.dooba.beta.Fragment1$1.done(Fragment1.java:105)
08-16 21:53:16.401: E/AndroidRuntime(1345): at com.parse.FindCallback.internalDone(FindCallback.java:45)
08-16 21:53:16.401: E/AndroidRuntime(1345): at com.parse.FindCallback.internalDone(FindCallback.java:1)
08-16 21:53:16.401: E/AndroidRuntime(1345): at com.parse.Parse$6$1.run(Parse.java:888)
08-16 21:53:16.401: E/AndroidRuntime(1345): at android.os.Handler.handleCallback(Handler.java:733)
08-16 21:53:16.401: E/AndroidRuntime(1345): at android.os.Handler.dispatchMessage(Handler.java:95)
08-16 21:53:16.401: E/AndroidRuntime(1345): at android.os.Looper.loop(Looper.java:136)
08-16 21:53:16.401: E/AndroidRuntime(1345): at android.app.ActivityThread.main(ActivityThread.java:5017)
08-16 21:53:16.401: E/AndroidRuntime(1345): at java.lang.reflect.Method.invokeNative(Native Method)
08-16 21:53:16.401: E/AndroidRuntime(1345): at java.lang.reflect.Method.invoke(Method.java:515)
08-16 21:53:16.401: E/AndroidRuntime(1345): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
08-16 21:53:16.401: E/AndroidRuntime(1345): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
08-16 21:53:16.401: E/AndroidRuntime(1345): at dalvik.system.NativeStart.main(Native Method)
public class Fragment1 extends Fragment {
private String currentUserId;
private ArrayAdapter<String> namesArrayAdapter;
private ArrayList<String> names;
private ArrayList<Images> alProfilePicture;
private ListView usersListView;
private Button logoutButton;
String userGender = ParseUser.getCurrentUser().getString("Gender");
String activityName = ParseUser.getCurrentUser().getString("ActivityName");
Number maxDistance = ParseUser.getCurrentUser().getNumber("Maximum_Distance");
String userLookingGender = ParseUser.getCurrentUser().getString("Looking_Gender");
Number minimumAge = ParseUser.getCurrentUser().getNumber("Minimum_Age");
Number maximumAge = ParseUser.getCurrentUser().getNumber("Maximum_Age");
Number userage = ParseUser.getCurrentUser().getNumber("Age");
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
setConversationsList();
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment1_layout, container, false);
return view;
}
private void setConversationsList() {
currentUserId = ParseUser.getCurrentUser().getObjectId();
names = new ArrayList<String>();
alProfilePicture = new ArrayList<Images>();
// String userActivitySelectionName = null;
ParseQuery<ParseUser> query = ParseUser.getQuery();
// query.whereEqualTo("ActivityName",userActivitySelectionName);
query.whereNotEqualTo("objectId", ParseUser.getCurrentUser().getObjectId());
// users with Gender = currentUser.Looking_Gender
query.whereEqualTo("Gender", userLookingGender);
// users with Looking_Gender = currentUser.Gender
query.whereEqualTo("Looking_Gender", userGender);
query.setLimit(1);
query.whereEqualTo("ActivityName", activityName);
//query.whereGreaterThanOrEqualTo("Age", minimumAge);
//query.whereLessThanOrEqualTo("Age", maximumAge);
query.orderByDescending("Name");
query.findInBackground(new FindCallback<ParseUser>() {
public void done(List<ParseUser> userList, ParseException e) {
if (e == null) {
for (int i=0; i<userList.size(); i++) {
names.add(userList.get(i).get("Name").toString());
names.add(userList.get(i).get("Headline").toString());
alProfilePicture.add((Images) userList.get(i).get("ProfilePicture"));
names.add(userList.get(i).get("Age").toString());
names.add(userList.get(i).get("ActivityName").toString());
// names.add(userList.get(i).getParseObject("ProfilePicture").;
}
usersListView = (ListView)getActivity().findViewById(R.id.userlistview);
namesArrayAdapter =
new ArrayAdapter<String>(getActivity().getApplicationContext(),
R.layout.user_list_item, names);
usersListView.setAdapter(namesArrayAdapter);
usersListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> a, View v, int i, long l) {
openConversation(names, i);
}
});
} else {
Toast.makeText(getActivity().getApplicationContext(),
"Error loading user list",
Toast.LENGTH_LONG).show();
}
}
});
}
public void openConversation(ArrayList<String> names, int pos) {
ParseQuery<ParseUser> query = ParseUser.getQuery();
query.whereEqualTo("Name", names.get(pos));
query.findInBackground(new FindCallback<ParseUser>() {
public void done(List<ParseUser> user, ParseException e) {
if (e == null) {
Intent intent = new Intent(getActivity().getApplicationContext(), MessagingActivity.class);
intent.putExtra("RECIPIENT_ID", user.get(0).getObjectId());
startActivity(intent);
} else {
Toast.makeText(getActivity().getApplicationContext(),
"Error finding that user",
Toast.LENGTH_SHORT).show();
}
}
});
}
}
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="@drawable/bac_blue"
android:orientation="vertical" >
<ListView
android:id="@+id/userlistname"
android:layout_width="220dp"
android:layout_centerHorizontal="true"
android:layout_height="50dp"
android:divider="@null"
>
</ListView>
<ListView
android:id="@+id/userlistheadline"
android:layout_width="220dp"
android:layout_below="@+id/userlistname"
android:layout_centerHorizontal="true"
android:layout_height="50dp"
android:divider="@null"
>
</ListView>
<ImageView
android:id="@+id/profilePictureresult"
android:layout_width="132dp"
android:layout_height="120dp"
android:layout_below="@+id/userlistheadline"
android:layout_centerHorizontal="true"
android:layout_marginTop="7dp"
android:layout_marginBottom="9dp"
android:padding="3dp"
android:scaleType="centerCrop"
android:cropToPadding="true"
android:background="@drawable/border_image"
android:alpha="1" />
<ListView
android:id="@+id/userlistage"
android:layout_width="220dp"
android:layout_below="@+id/profilePictureresult"
android:layout_centerHorizontal="true"
android:layout_height="50dp"
android:divider="@null"
>
</ListView>
<ListView
android:id="@+id/userlistactivityname"
android:layout_width="220dp"
android:layout_below="@+id/profilePictureresult"
android:layout_centerHorizontal="true"
android:layout_height="50dp"
android:divider="@null"
>
</ListView>
<Button
android:id="@+id/button1"
android:layout_below="@+id/userlistactivityname"
android:layout_centerHorizontal="true"
android:layout_width="100dp"
android:layout_height="50dp"
android:layout_marginTop="12dp"
android:alpha="0.7"
android:textColor="#000000"
android:background="#ADD8E6"
android:textSize="22sp"
android:typeface="serif"
android:text="Confirm" />
<ImageView
android:id="@+id/imageView2"
android:layout_width="70dp"
android:layout_height="50dp"
android:layout_alignParentRight="true"
android:layout_alignTop="@+id/imageView1"
android:alpha="0.7"
android:src="@drawable/left_right" />
<ImageView
android:id="@+id/imageView1"
android:layout_width="70dp"
android:layout_height="50dp"
android:layout_alignBottom="@+id/userlistview"
android:layout_alignParentLeft="true"
android:layout_marginBottom="119dp"
android:alpha="0.7"
android:src="@drawable/left_arrow2" />
</RelativeLayout>
ParseQuery<ParseObject> query = ParseQuery.getQuery("User");
query.getFirstInBackground(new GetCallback<ParseObject>() {
public void done(ParseObject object, ParseException e) {
if (object != null) {
ParseFile file = (ParseFile)object.get("Profile_Picture");
file.getDataInBackground(new GetDataCallback() {
public void done(byte[] data, ParseException e) {
if (e == null) {
bitmap=BitmapFactory.decodeByteArray(data, 0, data.length);
//use this bitmap as you want
} else {
// something went wrong
}
}
});
} else {
// Toast.makeText(getApplicationContext(), "Exception", Toast.LENGTH_SHORT) .show();
}
}
});
ParseQuery query=ParseQuery.getQuery（“用户”）；
getFirstInBackground（新的GetCallback（）{
公共无效完成（ParseObject对象，parsee异常）{
if（对象！=null）{
ParseFile file=（ParseFile）object.get（“Profile_Picture”）；
getDataInBackground（新的GetDataCallback（）{
公共无效完成（字节[]数据，解析异常e）{
如果（e==null）{
位图=位图工厂.decodeByteArray（数据，0，数据.length）；
//根据需要使用此位图
}否则{
//出了点问题
}
}
});
}否则{
//Toast.makeText（getApplicationContext（），“Exception”，Toast.LENGTH\u SHORT.show（）；
}
}
});
public class Fragment1 extends Fragment {
private String currentUserId;
private ArrayAdapter<String> namesArrayAdapter;
private ArrayList<String> names;
private ArrayList<Images> alProfilePicture;
private ListView usersListView;
private Button logoutButton;
String userGender = ParseUser.getCurrentUser().getString("Gender");
String activityName = ParseUser.getCurrentUser().getString("ActivityName");
Number maxDistance = ParseUser.getCurrentUser().getNumber("Maximum_Distance");
String userLookingGender = ParseUser.getCurrentUser().getString("Looking_Gender");
Number minimumAge = ParseUser.getCurrentUser().getNumber("Minimum_Age");
Number maximumAge = ParseUser.getCurrentUser().getNumber("Maximum_Age");
Number userage = ParseUser.getCurrentUser().getNumber("Age");
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
setConversationsList();
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment1_layout, container, false);
return view;
}
private void setConversationsList() {
currentUserId = ParseUser.getCurrentUser().getObjectId();
names = new ArrayList<String>();
alProfilePicture = new ArrayList<Images>();
// String userActivitySelectionName = null;
ParseQuery<ParseUser> query = ParseUser.getQuery();
// query.whereEqualTo("ActivityName",userActivitySelectionName);
query.whereNotEqualTo("objectId", ParseUser.getCurrentUser().getObjectId());
// users with Gender = currentUser.Looking_Gender
query.whereEqualTo("Gender", userLookingGender);
// users with Looking_Gender = currentUser.Gender
query.whereEqualTo("Looking_Gender", userGender);
query.setLimit(1);
query.whereEqualTo("ActivityName", activityName);
//query.whereGreaterThanOrEqualTo("Age", minimumAge);
//query.whereLessThanOrEqualTo("Age", maximumAge);
query.orderByDescending("Name");
query.findInBackground(new FindCallback<ParseUser>() {
public void done(List<ParseUser> userList, ParseException e) {
if (e == null) {
for (int i=0; i<userList.size(); i++) {
names.add(userList.get(i).get("Name").toString());
names.add(userList.get(i).get("Headline").toString());
names.add(userList.get(i).get("Age").toString());
names.add(userList.get(i).get("ActivityName").toString());
ParseQuery<ParseObject> query = ParseQuery.getQuery("User");
query.getFirstInBackground(new GetCallback<ParseObject>() {
public void done(ParseObject object, ParseException e) {
if (object != null) {
ParseFile file = (ParseFile)object.get("Profile_Picture");
file.getDataInBackground(new GetDataCallback() {
public void done(byte[] data, ParseException e) {
if (e == null) {
Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);
//use this bitmap as you want
} else {
// something went wrong
}
}
});
} else {
// Toast.makeText(getApplicationContext(), "Exception", Toast.LENGTH_SHORT) .show();
}
}
});
// names.add(userList.get(i).getParseObject("ProfilePicture").;
}
usersListView = (ListView)getActivity().findViewById(R.id.userlistview);
namesArrayAdapter =
new ArrayAdapter<String>(getActivity().getApplicationContext(),
R.layout.user_list_item, names);
usersListView.setAdapter(namesArrayAdapter);
usersListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> a, View v, int i, long l) {
openConversation(names, i);
}
});
} else {
Toast.makeText(getActivity().getApplicationContext(),
"Error loading user list",
Toast.LENGTH_LONG).show();
}
}
});
}
public void openConversation(ArrayList<String> names, int pos) {
ParseQuery<ParseUser> query = ParseUser.getQuery();
query.whereEqualTo("Name", names.get(pos));
query.findInBackground(new FindCallback<ParseUser>() {
public void done(List<ParseUser> user, ParseException e) {
if (e == null) {
Intent intent = new Intent(getActivity().getApplicationContext(), MessagingActivity.class);
intent.putExtra("RECIPIENT_ID", user.get(0).getObjectId());
startActivity(intent);
} else {
Toast.makeText(getActivity().getApplicationContext(),
"Error finding that user",
Toast.LENGTH_SHORT).show();
}
}
});
}
}
公共类Fragment1扩展了Fragment{
私有字符串currentUserId；
私有ArrayAdapter名称ArrayAdapter；
私有数组列表名称；
私人ArrayList alProfilePicture；
私有列表视图用户列表视图；
私人按钮注销按钮；
字符串userGender=ParseUser.getCurrentUser（）.getString（“性别”）；
String activityName=ParseUser.getCurrentUser（）.getString（“activityName”）；
Number maxDistance=ParseUser.getCurrentUser（）.getNumber（“最大_距离”）；
String userLookingGender=ParseUser.getCurrentUser（）.getString（“Looking_-Gender”）；
Number minimumAge=ParseUser.getCurrentUser（）.getNumber（“最小年龄”）；
Number maximumAge=ParseUser.getCurrentUser（）.getNumber（“最大年龄”）；
Number userage=ParseUser.getCurrentUser（）.getNumber（“年龄”）；
@凌驾
已创建ActivityState上的公共无效（Bundle savedInstanceState）{
super.onActivityCreated（savedInstanceState）；
setConversationsList（）；
}
@凌驾
CreateView上的公共视图（布局、充气机、视图组容器、捆绑包保存状态）{
视图=充气机。充气（右布局。碎片1_布局，容器，假）；
返回视图；
}
私有void setConversationsList（）{
currentUserId=ParseUser.getCurrentUser（）.getObjectId（）；
名称=新的ArrayList（）；
alProfilePicture=newarraylist（）；
//字符串userActivitySelectionName=null；
ParseQuery=ParseUser.getQuery（）；
//query.whereEqualTo（“ActivityName”，userActivitySelectionName）；
query.whereNotEqualTo（“objectId”，ParseUser.getCurrentUser（）.getObjectId（））；
//性别=currentUser.Looking\u性别的用户
查询：whereEqualTo（“性别”，userLookingGender）；
//具有Looking_Gender=currentUser.Gender的用户
查询：whereEqualTo（“寻找性别”，用户性别）；
查询设置限制（1）；
查询。whereEqualTo（“活动名称”，活动名称）；
//查询。其中大于或等于（“年龄”，最小年龄）；
//查询，其中为“年龄”，最大年龄；
query.orderByDescending（“名称”）；
findInBackground（新的FindCallback（）{
public void done（List userList，parsee异常）{
如果（e==null）{
对于（int i=0；i，您不能简单地从parse get（“ProfilePicture”）获取数据并将其转换为图像。它不是类图像，而是一个ParseFile。您需要将ParseFile中的数据转换为位图，并在应用程序中使用位图
演示如何将解析文件转换为用于在后台构建位图的字节数组。关于问题所在，您是对的
profilepic.add（images）…行需要一些工作。但我认为您应该阅读一些框架方面的内容，然后返回到列表和arrayAdapter的实现
模式和列表
像“毕加索”或“大学图像加载器”或“阿奎里”，你需要知道它们是做什么的，为什么它们是必不可少的
您不想管理位图列表或图像列表。有一些优化的图像加载程序框架，您应该评估并选择其中一个，学习并使用它
你迟早会遇到内存问题，用图像/位图列表自己做任何事情
请记住，对封装指向解析上载照片实例的指针的解析类的任何调用都将返回对Uri进行某种逻辑引用的字符串。此Uri是一个MIME类型为“image/*”的https协议网络对象。当您使用指针对parse类执行GET操作时，会得到一个JSON包装器，您可以执行类似的操作来获取URL
"media4":{"__type":"File","name":"..-picf1","url":"http://files.parse.com/...c8652d6-picf1"}
JSONObject jsonObj = new VideoProvider().parseUrl(url, ctx); // get the parse wrapper cls
// aloop to get list entries from parse response will get 'media4'
String imageurl = media4.getString("url");
其中“media4”是解析响应中的JSON对象，用于获取包装图像的类。
Parse是为了与任何imageLoading框架协作而构建的，因为您只需向框架提供一个字符串（Url）或一个Uri即可完成其余工作。（从Uri获取位图，并将其加载到ArrayAdapters调用“getView（）”的上下文中的imageView。）
返回到视图持有者和图像加载程序
Viewholder的构造函数只是将Uri加载到字段中
然后在“convertView”中传递2个字段（它们实际上是任何ImageLoader框架的通用接口）<
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="@drawable/bac_blue"
android:orientation="vertical" >
<ListView
android:id="@+id/userlistname"
android:layout_width="220dp"
android:layout_centerHorizontal="true"
android:layout_height="50dp"
android:divider="@null"
>
</ListView>
<ListView
android:id="@+id/userlistheadline"
android:layout_width="220dp"
android:layout_below="@+id/userlistname"
android:layout_centerHorizontal="true"
android:layout_height="50dp"
android:divider="@null"
>
</ListView>
<ImageView
android:id="@+id/profilePictureresult"
android:layout_width="132dp"
android:layout_height="120dp"
android:layout_below="@+id/userlistheadline"
android:layout_centerHorizontal="true"
android:layout_marginTop="7dp"
android:layout_marginBottom="9dp"
android:padding="3dp"
android:scaleType="centerCrop"
android:cropToPadding="true"
android:background="@drawable/border_image"
android:alpha="1" />
<ListView
android:id="@+id/userlistage"
android:layout_width="220dp"
android:layout_below="@+id/profilePictureresult"
android:layout_centerHorizontal="true"
android:layout_height="50dp"
android:divider="@null"
>
</ListView>
<ListView
android:id="@+id/userlistactivityname"
android:layout_width="220dp"
android:layout_below="@+id/profilePictureresult"
android:layout_centerHorizontal="true"
android:layout_height="50dp"
android:divider="@null"
>
</ListView>
<Button
android:id="@+id/button1"
android:layout_below="@+id/userlistactivityname"
android:layout_centerHorizontal="true"
android:layout_width="100dp"
android:layout_height="50dp"
android:layout_marginTop="12dp"
android:alpha="0.7"
android:textColor="#000000"
android:background="#ADD8E6"
android:textSize="22sp"
android:typeface="serif"
android:text="Confirm" />
<ImageView
android:id="@+id/imageView2"
android:layout_width="70dp"
android:layout_height="50dp"
android:layout_alignParentRight="true"
android:layout_alignTop="@+id/imageView1"
android:alpha="0.7"
android:src="@drawable/left_right" />
<ImageView
android:id="@+id/imageView1"
android:layout_width="70dp"
android:layout_height="50dp"
android:layout_alignBottom="@+id/userlistview"
android:layout_alignParentLeft="true"
android:layout_marginBottom="119dp"
android:alpha="0.7"
android:src="@drawable/left_arrow2" />
</RelativeLayout>
query.findInBackground(new FindCallback<ParseUser>() {
public void done(ParseObject object,ParseException e) {
ParseQuery<ParseObject> query = ParseQuery.getQuery("User");
query.getFirstInBackground(new GetCallback<ParseObject>() {
public void done(ParseObject object, ParseException e) {
if (object != null) {
ParseFile file = (ParseFile)object.get("ProfilePicture");
file.getDataInBackground(new GetDataCallback() {
public void done(byte[] data, ParseException e) {
if (e == null) {
Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);
//use this bitmap as you want
ImageView profileimage =(ImageView) getView().findViewById(R.id.profilePictureResult);
// Set the Bitmap into the
// ImageView
profileimage.setImageBitmap(bitmap);
Log.e("works", e.getMessage());
e.printStackTrace();
} else {
// something went wrong
Log.e("Error", e.getMessage());
e.printStackTrace();
}
}
});
} else {
// Toast.makeText(getApplicationContext(), "Exception", Toast.LENGTH_SHORT) .show();
Log.e("Error 2", e.getMessage());
e.printStackTrace();
}
}
});
}
"media4":{"__type":"File","name":"..-picf1","url":"http://files.parse.com/...c8652d6-picf1"}
JSONObject jsonObj = new VideoProvider().parseUrl(url, ctx); // get the parse wrapper cls
// aloop to get list entries from parse response will get 'media4'
String imageurl = media4.getString("url");