在片段中使用上下文
Using context in fragments
我是 Android 的初学者。在这里，尝试将列表视图添加到我的项目中，其中片段用于导航抽屉。因此，我遇到了以下错误。下面是我的 activity 代码：
import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import java.util.ArrayList;
public class Menu1 extends Fragment {
private ArrayList<Property> rentalProperties = new ArrayList<>();
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
//returning our layout file
//change R.layout.yourlayoutfilename for each of your fragments
return inflater.inflate(R.layout.fragment_all, container, false);
}
@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
//you can set the title for your toolbar here for different fragments different titles
getActivity().setTitle("All");
//create property elements
}
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.fragment_all);
//create our property elements
rentalProperties.add(new Property(10, "Smith Street", "Sydney", "NSW", "A large 3 bedroom apartment right in the heart of Sydney! A rare find, with 3 bedrooms and a secured car park.", 450.00, "property_image_1", 3, 1, 1, false));
rentalProperties.add(new Property(66, "King Street", "Sydney", "NSW", "A fully furnished studio apartment overlooking the harbour. Minutes from the CBD and next to transport, this is a perfect set-up for city living.", 320.00, "property_image_2", 1, 1, 1, false));
rentalProperties.add(new Property(1, "Liverpool Road", "Liverpool", "NSW", "A standard 3 bedroom house in the suburbs. With room for several cars and right next to shops this is perfect for new families.", 360.00, "property_image_3", 3, 2, 2, true));
rentalProperties.add(new Property(567, "Sunny Street", "Gold Coast", "QLD", "Come and see this amazing studio apartment in the heart of the gold coast, featuring stunning waterfront views.", 360.00, "property_image_4" , 1, 1, 1, false));
//create our new array adapter
ArrayAdapter<Property> adapter = new propertyArrayAdapter(this, 0, rentalProperties);
//Find list view and bind it with the custom adapter
ListView listView = (ListView) findViewById(R.id.customListView);
listView.setAdapter(adapter);
//add event listener so we can handle clicks
AdapterView.OnItemClickListener adapterViewListener = new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Property property = rentalProperties.get(position);
Intent intent = new Intent(Menu1.this, DetailActivity.class);
intent.putExtra("streetNumber", property.getStreetNumber());
intent.putExtra("streetName", property.getStreetName());
intent.putExtra("suburb", property.getSuburb());
intent.putExtra("state", property.getState());
intent.putExtra("image", property.getImage());
startActivityForResult(intent, 1000);
}
};
//set the listener to the list view
listView.setOnItemClickListener(adapterViewListener);
}
}
显示了三个错误，它们是：
1) setContentView(R.layout.fragment_all);
Error:(43, 9) error: cannot find symbol method setContentView(int)
2) ListView listView = (ListView) findViewById(R.id.customListView);
Error:(55, 40) error: cannot find symbol method findViewById(int)
3) ArrayAdapter 适配器 = new propertyArrayAdapter(this, 0,
出租物业）；
Error:(52, 67) error: incompatible types: Menu1 cannot be converted to
Context
4) Intent intent = new Intent(Menu1.this, DetailActivity.class);
Error:(67, 33) error: no suitable constructor found for
Intent(Menu1,Class<DetailActivity>)
constructor Intent.Intent(String,Uri) is not applicable
(argument mismatch; Menu1 cannot be converted to String)
constructor Intent.Intent(Context,Class<?>) is not applicable
(argument mismatch; Menu1 cannot be converted to Context)
以上给出的问题已通过下面给出的答案进行修正，标记为答案。但是在这里我遇到了布局问题。布局不适合屏幕，每一边都有一些空白 space。在布局中尝试了不同的方法，但没有改变。布局代码如下：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="700dp"
android:layout_height="400dp"
android:orientation="vertical"
android:paddingTop="-10dp"
android:paddingBottom="10dp">
<LinearLayout
android:id="@+id/infoSection"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:weightSum="1">
<TextView
android:id="@+id/filename"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginBottom="10dp"
android:text="Filename"
android:textSize="15dp"
android:layout_weight="2.35" />
<ProgressBar
style="?android:attr/progressBarStyleHorizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/progressBar"
android:layout_weight="2.35"
android:layout_marginTop="-10dp"/>
</LinearLayout>
<RelativeLayout
android:id="@+id/pricingSection"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@+id/infoSection"
android:orientation="vertical">
<LinearLayout
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<LinearLayout
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:text="Status"
android:layout_width="172dp"
android:layout_height="wrap_content"
android:id="@+id/status" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginRight="15dp"
android:text="Size:"
android:layout_weight="1.07" />
<TextView
android:text="sz"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/size"
android:layout_weight="1" />
</LinearLayout>
<LinearLayout
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="match_parent">
</LinearLayout>
<LinearLayout
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginRight="15dp"
android:layout_toRightOf="@id/size"
android:text="Progress:"
android:layout_weight="0.36" />
<TextView
android:text="pg"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/progress"
android:layout_weight="1.65" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Speed:"
android:layout_marginLeft="25dp"
android:layout_toRightOf="@+id/progress"
android:layout_weight="0.87" />
<TextView
android:text="sp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/speed"
android:layout_weight="1.86" />
</LinearLayout>
</LinearLayout>
</RelativeLayout>
</RelativeLayout>
1) 片段中的 setContentView(R.layout.fragment_all); 替换为 return inflater.inflate(R.layout.fragment_all, container, false);
2) ListView listView = (ListView) findViewById(R.id.customListView);
将其替换为：ListView listView = (ListView) getActivity().findViewById(R.id.customListView);
3) ArrayAdapter adapter = new propertyArrayAdapter(this, 0, rentalProperties);
将其替换为 ArrayAdapter adapter = new propertyArrayAdapter(getActivity(), 0, rentalProperties); // getActivity() it's ur context
4) Intent intent = new Intent(Menu1.this, DetailActivity.class);
将其替换为 4) Intent intent = new Intent(getActivity(), DetailActivity.class);
希望有所帮助:)
1) setContentView(R.layout.fragment_all);
对于 fragment，您必须在 onCreateView() 中膨胀视图。不要将 setContentView(R.layout.fragment_all); 用于 fragment;
2) ListView listView = (ListView) findViewById(R.id.customListView);
您必须在片段中将视图作为父视图的子视图。在下面的代码中，rootView 是父级，所以我将 ListView 初始化为：
ListView listView = (ListView) rootView.findViewById(R.id.customListView);
3) ArrayAdapter adapter = new propertyArrayAdapter(this, 0,
rentalProperties);
您必须获取包含片段的 activity 的上下文：
ArrayAdapter adapter = new propertyArrayAdapter(getActivity(), 0, rentalProperties);
4) Intent intent = new Intent(Menu1.this, DetailActivity.class);
将其替换为：
Intent intent = new Intent(getActivity(), DetailActivity.class);
最后将所有代码从onCreate()移动到onCreateView()如下：
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
//returning our layout file
//change R.layout.yourlayoutfilename for each of your fragments
View rootView = inflater.inflate(R.layout.fragment_all, container, false);
rentalProperties.add(new Property(10, "Smith Street", "Sydney", "NSW", "A large 3 bedroom apartment right in the heart of Sydney! A rare find, with 3 bedrooms and a secured car park.", 450.00, "property_image_1", 3, 1, 1, false));
rentalProperties.add(new Property(66, "King Street", "Sydney", "NSW", "A fully furnished studio apartment overlooking the harbour. Minutes from the CBD and next to transport, this is a perfect set-up for city living.", 320.00, "property_image_2", 1, 1, 1, false));
rentalProperties.add(new Property(1, "Liverpool Road", "Liverpool", "NSW", "A standard 3 bedroom house in the suburbs. With room for several cars and right next to shops this is perfect for new families.", 360.00, "property_image_3", 3, 2, 2, true));
rentalProperties.add(new Property(567, "Sunny Street", "Gold Coast", "QLD", "Come and see this amazing studio apartment in the heart of the gold coast, featuring stunning waterfront views.", 360.00, "property_image_4" , 1, 1, 1, false));
//create our new array adapter
ArrayAdapter<Property> adapter = new propertyArrayAdapter(getActivity(), 0, rentalProperties);
//Find list view and bind it with the custom adapter
ListView listView = (ListView)rootView. findViewById(R.id.customListView);
listView.setAdapter(adapter);
//add event listener so we can handle clicks
AdapterView.OnItemClickListener adapterViewListener = new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Property property = rentalProperties.get(position);
Intent intent = new Intent(getActivity(), DetailActivity.class);
intent.putExtra("streetNumber", property.getStreetNumber());
intent.putExtra("streetName", property.getStreetName());
intent.putExtra("suburb", property.getSuburb());
intent.putExtra("state", property.getState());
intent.putExtra("image", property.getImage());
startActivityForResult(intent, 1000);
}
};
//set the listener to the list view
listView.setOnItemClickListener(adapterViewListener);
return rootView;
}
希望这对您有所帮助。
我是 Android 的初学者。在这里，尝试将列表视图添加到我的项目中，其中片段用于导航抽屉。因此，我遇到了以下错误。下面是我的 activity 代码：
import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import java.util.ArrayList;
public class Menu1 extends Fragment {
private ArrayList<Property> rentalProperties = new ArrayList<>();
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
//returning our layout file
//change R.layout.yourlayoutfilename for each of your fragments
return inflater.inflate(R.layout.fragment_all, container, false);
}
@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
//you can set the title for your toolbar here for different fragments different titles
getActivity().setTitle("All");
//create property elements
}
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.fragment_all);
//create our property elements
rentalProperties.add(new Property(10, "Smith Street", "Sydney", "NSW", "A large 3 bedroom apartment right in the heart of Sydney! A rare find, with 3 bedrooms and a secured car park.", 450.00, "property_image_1", 3, 1, 1, false));
rentalProperties.add(new Property(66, "King Street", "Sydney", "NSW", "A fully furnished studio apartment overlooking the harbour. Minutes from the CBD and next to transport, this is a perfect set-up for city living.", 320.00, "property_image_2", 1, 1, 1, false));
rentalProperties.add(new Property(1, "Liverpool Road", "Liverpool", "NSW", "A standard 3 bedroom house in the suburbs. With room for several cars and right next to shops this is perfect for new families.", 360.00, "property_image_3", 3, 2, 2, true));
rentalProperties.add(new Property(567, "Sunny Street", "Gold Coast", "QLD", "Come and see this amazing studio apartment in the heart of the gold coast, featuring stunning waterfront views.", 360.00, "property_image_4" , 1, 1, 1, false));
//create our new array adapter
ArrayAdapter<Property> adapter = new propertyArrayAdapter(this, 0, rentalProperties);
//Find list view and bind it with the custom adapter
ListView listView = (ListView) findViewById(R.id.customListView);
listView.setAdapter(adapter);
//add event listener so we can handle clicks
AdapterView.OnItemClickListener adapterViewListener = new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Property property = rentalProperties.get(position);
Intent intent = new Intent(Menu1.this, DetailActivity.class);
intent.putExtra("streetNumber", property.getStreetNumber());
intent.putExtra("streetName", property.getStreetName());
intent.putExtra("suburb", property.getSuburb());
intent.putExtra("state", property.getState());
intent.putExtra("image", property.getImage());
startActivityForResult(intent, 1000);
}
};
//set the listener to the list view
listView.setOnItemClickListener(adapterViewListener);
}
}
显示了三个错误，它们是：
1) setContentView(R.layout.fragment_all);
Error:(43, 9) error: cannot find symbol method setContentView(int)
2) ListView listView = (ListView) findViewById(R.id.customListView);
Error:(55, 40) error: cannot find symbol method findViewById(int)
3) ArrayAdapter 适配器 = new propertyArrayAdapter(this, 0, 出租物业）；
Error:(52, 67) error: incompatible types: Menu1 cannot be converted to
Context
4) Intent intent = new Intent(Menu1.this, DetailActivity.class);
Error:(67, 33) error: no suitable constructor found for
Intent(Menu1,Class<DetailActivity>)
constructor Intent.Intent(String,Uri) is not applicable
(argument mismatch; Menu1 cannot be converted to String)
constructor Intent.Intent(Context,Class<?>) is not applicable
(argument mismatch; Menu1 cannot be converted to Context)
以上给出的问题已通过下面给出的答案进行修正，标记为答案。但是在这里我遇到了布局问题。布局不适合屏幕，每一边都有一些空白 space。在布局中尝试了不同的方法，但没有改变。布局代码如下：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="700dp"
android:layout_height="400dp"
android:orientation="vertical"
android:paddingTop="-10dp"
android:paddingBottom="10dp">
<LinearLayout
android:id="@+id/infoSection"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:weightSum="1">
<TextView
android:id="@+id/filename"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginBottom="10dp"
android:text="Filename"
android:textSize="15dp"
android:layout_weight="2.35" />
<ProgressBar
style="?android:attr/progressBarStyleHorizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/progressBar"
android:layout_weight="2.35"
android:layout_marginTop="-10dp"/>
</LinearLayout>
<RelativeLayout
android:id="@+id/pricingSection"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@+id/infoSection"
android:orientation="vertical">
<LinearLayout
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<LinearLayout
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:text="Status"
android:layout_width="172dp"
android:layout_height="wrap_content"
android:id="@+id/status" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginRight="15dp"
android:text="Size:"
android:layout_weight="1.07" />
<TextView
android:text="sz"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/size"
android:layout_weight="1" />
</LinearLayout>
<LinearLayout
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="match_parent">
</LinearLayout>
<LinearLayout
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginRight="15dp"
android:layout_toRightOf="@id/size"
android:text="Progress:"
android:layout_weight="0.36" />
<TextView
android:text="pg"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/progress"
android:layout_weight="1.65" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Speed:"
android:layout_marginLeft="25dp"
android:layout_toRightOf="@+id/progress"
android:layout_weight="0.87" />
<TextView
android:text="sp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/speed"
android:layout_weight="1.86" />
</LinearLayout>
</LinearLayout>
</RelativeLayout>
</RelativeLayout>
1) 片段中的 setContentView(R.layout.fragment_all); 替换为 return inflater.inflate(R.layout.fragment_all, container, false);
2) ListView listView = (ListView) findViewById(R.id.customListView);
将其替换为：ListView listView = (ListView) getActivity().findViewById(R.id.customListView);
3) ArrayAdapter adapter = new propertyArrayAdapter(this, 0, rentalProperties);
将其替换为 ArrayAdapter adapter = new propertyArrayAdapter(getActivity(), 0, rentalProperties); // getActivity() it's ur context
4) Intent intent = new Intent(Menu1.this, DetailActivity.class);
将其替换为 4) Intent intent = new Intent(getActivity(), DetailActivity.class);
希望有所帮助:)
1) setContentView(R.layout.fragment_all);
对于 fragment，您必须在 onCreateView() 中膨胀视图。不要将 setContentView(R.layout.fragment_all); 用于 fragment;
2) ListView listView = (ListView) findViewById(R.id.customListView);
您必须在片段中将视图作为父视图的子视图。在下面的代码中，rootView 是父级，所以我将 ListView 初始化为：
ListView listView = (ListView) rootView.findViewById(R.id.customListView);
3) ArrayAdapter adapter = new propertyArrayAdapter(this, 0, rentalProperties);
您必须获取包含片段的 activity 的上下文：
ArrayAdapter adapter = new propertyArrayAdapter(getActivity(), 0, rentalProperties);
4) Intent intent = new Intent(Menu1.this, DetailActivity.class);
将其替换为：
Intent intent = new Intent(getActivity(), DetailActivity.class);
最后将所有代码从onCreate()移动到onCreateView()如下：
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
//returning our layout file
//change R.layout.yourlayoutfilename for each of your fragments
View rootView = inflater.inflate(R.layout.fragment_all, container, false);
rentalProperties.add(new Property(10, "Smith Street", "Sydney", "NSW", "A large 3 bedroom apartment right in the heart of Sydney! A rare find, with 3 bedrooms and a secured car park.", 450.00, "property_image_1", 3, 1, 1, false));
rentalProperties.add(new Property(66, "King Street", "Sydney", "NSW", "A fully furnished studio apartment overlooking the harbour. Minutes from the CBD and next to transport, this is a perfect set-up for city living.", 320.00, "property_image_2", 1, 1, 1, false));
rentalProperties.add(new Property(1, "Liverpool Road", "Liverpool", "NSW", "A standard 3 bedroom house in the suburbs. With room for several cars and right next to shops this is perfect for new families.", 360.00, "property_image_3", 3, 2, 2, true));
rentalProperties.add(new Property(567, "Sunny Street", "Gold Coast", "QLD", "Come and see this amazing studio apartment in the heart of the gold coast, featuring stunning waterfront views.", 360.00, "property_image_4" , 1, 1, 1, false));
//create our new array adapter
ArrayAdapter<Property> adapter = new propertyArrayAdapter(getActivity(), 0, rentalProperties);
//Find list view and bind it with the custom adapter
ListView listView = (ListView)rootView. findViewById(R.id.customListView);
listView.setAdapter(adapter);
//add event listener so we can handle clicks
AdapterView.OnItemClickListener adapterViewListener = new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Property property = rentalProperties.get(position);
Intent intent = new Intent(getActivity(), DetailActivity.class);
intent.putExtra("streetNumber", property.getStreetNumber());
intent.putExtra("streetName", property.getStreetName());
intent.putExtra("suburb", property.getSuburb());
intent.putExtra("state", property.getState());
intent.putExtra("image", property.getImage());
startActivityForResult(intent, 1000);
}
};
//set the listener to the list view
listView.setOnItemClickListener(adapterViewListener);
return rootView;
}
希望这对您有所帮助。