屏幕方向后保留卡片视图
Retaining cardview after screen orientation
我有一个进行异步调用的片段,分配给一个对象变量(我花了一段时间才弄清楚),然后通过单击一个按钮,它通过适配器将 cardviews
加载到屏幕中。
我使用的代码是:
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, final Bundle savedInstanceState) {
super.onCreateView(inflater, container, savedInstanceState);
View view = inflater.inflate(R.layout.fragments_stops_list, container, false);
ButterKnife.bind(this, view); // since this is a fragment the butterknife bind method should goafter the view declaration
// saved state would indicate that we are now not capable of making multiple requests. This point has been
// properly taken care of and now I can purposely move on to other things of more importance
loadButton = (Button) view.findViewById(R.id.LOAD);
if(savedInstanceState == null) {
loadButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Log.d(">==========<", extractCreate.getCreateR().getPhone());
Parcelable[] parcelable = extractCreate.getStopsR();
commodities = Arrays.copyOf(parcelable, parcelable.length, Stops[].class);
//Log.d("Commodities size check", String.valueOf(commodities.length));
StopsAdapter adapter = new StopsAdapter(commodities);
mRecyclerView.setAdapter(adapter);
RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(getActivity()); // sketchy on this part
mRecyclerView.setLayoutManager(layoutManager);
mRecyclerView.setHasFixedSize(true);
Log.d(TAG, "This is being called from the onCreate method");
}
});
}
return view;
}
问题是,如果我尝试旋转屏幕然后内容消失,要使它们再次出现必须单击按钮(id.LOAD
),我添加了一条语句来检查 saveInstance 是否state 为 null,当我转动屏幕时,该解决方案无法像现在这样工作,我通过适配器加载的 cardviews
消失并且不可能再次加载它们。
如何保存状态?我阅读了关于重写 onViewStateRestored
方法的内容,但这个想法似乎并不乐观,因为内容需要在点击侦听器内部处理。
如有任何建议,我们将不胜感激。
根据要求,这是.
的代码
public class Stops implements Parcelable{
private String stop_id;
private String type;
private String location;
private String address;
private String city;
private String state;
private String zip;
private String from;
private String to;
private String getitem;
private Commodities[] commodities;
public Stops() {}
public String getStop_id() {
return stop_id;
}
public void setStop_id(String stop_id) {
this.stop_id = stop_id;
}
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
public String getLocation() {
return location;
}
public void setLocation(String location) {
this.location = location;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
public String getCity() {
return city;
}
public void setCity(String city) {
this.city = city;
}
public String getState() {
return state;
}
public void setState(String state) {
this.state = state;
}
public String getZip() {
return zip;
}
public void setZip(String zip) {
this.zip = zip;
}
public String getFrom() {
return from;
}
public void setFrom(String from) {
this.from = from;
}
public String getTo() {
return to;
}
public void setTo(String to) {
this.to = to;
}
public Commodities[] getCommodities() {
return commodities;
}
public void setCommodities(Commodities[] commodities) {
this.commodities = commodities;
}
/**
* The content for the actual parcelables start in here
*
* */
@Override
public int describeContents() {
return 0;
}
@Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeString(this.stop_id);
dest.writeString(this.type);
dest.writeString(this.location);
dest.writeString(this.address);
dest.writeString(this.city);
dest.writeString(this.state);
dest.writeString(this.zip);
dest.writeString(this.from);
dest.writeString(this.to);
dest.writeString(this.getitem);
dest.writeTypedArray(this.commodities, flags);
}
protected Stops(Parcel in) {
this.stop_id = in.readString();
this.type = in.readString();
this.location = in.readString();
this.address = in.readString();
this.city = in.readString();
this.state = in.readString();
this.zip = in.readString();
this.from = in.readString();
this.to = in.readString();
this.getitem = in.readString();
this.commodities = in.createTypedArray(Commodities.CREATOR);
}
public static final Parcelable.Creator<Stops> CREATOR = new Parcelable.Creator<Stops>() {
@Override
public Stops createFromParcel(Parcel source) {
return new Stops(source);
}
@Override
public Stops[] newArray(int size) {
return new Stops[size];
}
};
}
由于当方向改变时你的片段正在被销毁并再次创建,你必须实现一些逻辑来保存你在方向改变事件之前收集的数据。
这是通过覆盖 onSavedInstanceState(Bundle bundle) 方法完成的。您需要保存的所有内容都包含在此处。您将数据放入 Bundle 对象并为其分配一个键,以便最近能够检索它。
当 OS 再次重新创建片段时,它将再次通过 onCreateView() 方法。这是您必须检查 savedInstanceState 对象是否不为 NULL 的地方。如果不是,那么它很可能包含一些在方向更改事件发生之前保存的数据。
查看以下要点。
public class SomeClass extends Activity {
private static final String KEY = "some_key";
commodities;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, final Bundle savedInstanceState) {
super.onCreateView(inflater, container, savedInstanceState);
View view = inflater.inflate(R.layout.fragments_stops_list, container, false);
ButterKnife.bind(this, view); // since this is a fragment the butterknife bind method should goafter the view declaration
// saved state would indicate that we are now not capable of making multiple requests. This point has been
// properly taken care of and now I can purposely move on to other things of more importance
loadButton = (Button) view.findViewById(R.id.LOAD);
if(savedInstanceState == null) {
loadButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Log.d(">==========<", extractCreate.getCreateR().getPhone());
Parcelable[] parcelable = extractCreate.getStopsR();
commodities = Arrays.copyOf(parcelable, parcelable.length, Stops[].class);
//Log.d("Commodities size check", String.valueOf(commodities.length));
StopsAdapter adapter = new StopsAdapter(commodities);
mRecyclerView.setAdapter(adapter);
RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(getActivity()); // sketchy on this part
mRecyclerView.setLayoutManager(layoutManager);
mRecyclerView.setHasFixedSize(true);
Log.d(TAG, "This is being called from the onCreate method");
}
});
} else {
if(savedInstanceState.containsKey(KEY)) {
commodities = savedInstanceState.getParcelable(KEY);
// here you will pretty much repete the code from above
// for creating an Adapter for the RecyclerView
StopsAdapter adapter = new StopsAdapter(commodities);
mRecyclerView.setAdapter(adapter);
RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(getActivity()); // sketchy on this part
mRecyclerView.setLayoutManager(layoutManager);
mRecyclerView.setHasFixedSize(true);
}
}
return view;
}
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putParcelable(KEY, commodities);
}
}
为了正确保存您的数据,您的商品 class 需要实施 Parcelable。查看此 link 了解更多信息。 Parcelable
P.S。
由于我不知道你的商品对象的实际类型,你将不得不稍微修改一下代码。只是简单的复制 -> 粘贴是行不通的!
将其放入清单
的Activity标签中
android:configChanges="orientation|keyboardHidden|screenSize"
希望对您有所帮助。
我有一个进行异步调用的片段,分配给一个对象变量(我花了一段时间才弄清楚),然后通过单击一个按钮,它通过适配器将 cardviews
加载到屏幕中。
我使用的代码是:
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, final Bundle savedInstanceState) {
super.onCreateView(inflater, container, savedInstanceState);
View view = inflater.inflate(R.layout.fragments_stops_list, container, false);
ButterKnife.bind(this, view); // since this is a fragment the butterknife bind method should goafter the view declaration
// saved state would indicate that we are now not capable of making multiple requests. This point has been
// properly taken care of and now I can purposely move on to other things of more importance
loadButton = (Button) view.findViewById(R.id.LOAD);
if(savedInstanceState == null) {
loadButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Log.d(">==========<", extractCreate.getCreateR().getPhone());
Parcelable[] parcelable = extractCreate.getStopsR();
commodities = Arrays.copyOf(parcelable, parcelable.length, Stops[].class);
//Log.d("Commodities size check", String.valueOf(commodities.length));
StopsAdapter adapter = new StopsAdapter(commodities);
mRecyclerView.setAdapter(adapter);
RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(getActivity()); // sketchy on this part
mRecyclerView.setLayoutManager(layoutManager);
mRecyclerView.setHasFixedSize(true);
Log.d(TAG, "This is being called from the onCreate method");
}
});
}
return view;
}
问题是,如果我尝试旋转屏幕然后内容消失,要使它们再次出现必须单击按钮(id.LOAD
),我添加了一条语句来检查 saveInstance 是否state 为 null,当我转动屏幕时,该解决方案无法像现在这样工作,我通过适配器加载的 cardviews
消失并且不可能再次加载它们。
如何保存状态?我阅读了关于重写 onViewStateRestored
方法的内容,但这个想法似乎并不乐观,因为内容需要在点击侦听器内部处理。
如有任何建议,我们将不胜感激。
根据要求,这是.
的代码public class Stops implements Parcelable{
private String stop_id;
private String type;
private String location;
private String address;
private String city;
private String state;
private String zip;
private String from;
private String to;
private String getitem;
private Commodities[] commodities;
public Stops() {}
public String getStop_id() {
return stop_id;
}
public void setStop_id(String stop_id) {
this.stop_id = stop_id;
}
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
public String getLocation() {
return location;
}
public void setLocation(String location) {
this.location = location;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
public String getCity() {
return city;
}
public void setCity(String city) {
this.city = city;
}
public String getState() {
return state;
}
public void setState(String state) {
this.state = state;
}
public String getZip() {
return zip;
}
public void setZip(String zip) {
this.zip = zip;
}
public String getFrom() {
return from;
}
public void setFrom(String from) {
this.from = from;
}
public String getTo() {
return to;
}
public void setTo(String to) {
this.to = to;
}
public Commodities[] getCommodities() {
return commodities;
}
public void setCommodities(Commodities[] commodities) {
this.commodities = commodities;
}
/**
* The content for the actual parcelables start in here
*
* */
@Override
public int describeContents() {
return 0;
}
@Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeString(this.stop_id);
dest.writeString(this.type);
dest.writeString(this.location);
dest.writeString(this.address);
dest.writeString(this.city);
dest.writeString(this.state);
dest.writeString(this.zip);
dest.writeString(this.from);
dest.writeString(this.to);
dest.writeString(this.getitem);
dest.writeTypedArray(this.commodities, flags);
}
protected Stops(Parcel in) {
this.stop_id = in.readString();
this.type = in.readString();
this.location = in.readString();
this.address = in.readString();
this.city = in.readString();
this.state = in.readString();
this.zip = in.readString();
this.from = in.readString();
this.to = in.readString();
this.getitem = in.readString();
this.commodities = in.createTypedArray(Commodities.CREATOR);
}
public static final Parcelable.Creator<Stops> CREATOR = new Parcelable.Creator<Stops>() {
@Override
public Stops createFromParcel(Parcel source) {
return new Stops(source);
}
@Override
public Stops[] newArray(int size) {
return new Stops[size];
}
};
}
由于当方向改变时你的片段正在被销毁并再次创建,你必须实现一些逻辑来保存你在方向改变事件之前收集的数据。
这是通过覆盖 onSavedInstanceState(Bundle bundle) 方法完成的。您需要保存的所有内容都包含在此处。您将数据放入 Bundle 对象并为其分配一个键,以便最近能够检索它。
当 OS 再次重新创建片段时,它将再次通过 onCreateView() 方法。这是您必须检查 savedInstanceState 对象是否不为 NULL 的地方。如果不是,那么它很可能包含一些在方向更改事件发生之前保存的数据。
查看以下要点。
public class SomeClass extends Activity {
private static final String KEY = "some_key";
commodities;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, final Bundle savedInstanceState) {
super.onCreateView(inflater, container, savedInstanceState);
View view = inflater.inflate(R.layout.fragments_stops_list, container, false);
ButterKnife.bind(this, view); // since this is a fragment the butterknife bind method should goafter the view declaration
// saved state would indicate that we are now not capable of making multiple requests. This point has been
// properly taken care of and now I can purposely move on to other things of more importance
loadButton = (Button) view.findViewById(R.id.LOAD);
if(savedInstanceState == null) {
loadButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Log.d(">==========<", extractCreate.getCreateR().getPhone());
Parcelable[] parcelable = extractCreate.getStopsR();
commodities = Arrays.copyOf(parcelable, parcelable.length, Stops[].class);
//Log.d("Commodities size check", String.valueOf(commodities.length));
StopsAdapter adapter = new StopsAdapter(commodities);
mRecyclerView.setAdapter(adapter);
RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(getActivity()); // sketchy on this part
mRecyclerView.setLayoutManager(layoutManager);
mRecyclerView.setHasFixedSize(true);
Log.d(TAG, "This is being called from the onCreate method");
}
});
} else {
if(savedInstanceState.containsKey(KEY)) {
commodities = savedInstanceState.getParcelable(KEY);
// here you will pretty much repete the code from above
// for creating an Adapter for the RecyclerView
StopsAdapter adapter = new StopsAdapter(commodities);
mRecyclerView.setAdapter(adapter);
RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(getActivity()); // sketchy on this part
mRecyclerView.setLayoutManager(layoutManager);
mRecyclerView.setHasFixedSize(true);
}
}
return view;
}
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putParcelable(KEY, commodities);
}
}
为了正确保存您的数据,您的商品 class 需要实施 Parcelable。查看此 link 了解更多信息。 Parcelable
P.S。 由于我不知道你的商品对象的实际类型,你将不得不稍微修改一下代码。只是简单的复制 -> 粘贴是行不通的!
将其放入清单
的Activity标签中 android:configChanges="orientation|keyboardHidden|screenSize"
希望对您有所帮助。