java - 项目点击 fragment 导致的 Activity 崩溃

Question

当我在选择项目“DEF”后单击“btn_search”按钮时，我的应用程序崩溃了，我不知道如何解决这个问题。

感谢您的帮助，抱歉我的英语不好，我是法国人。

我的代码(MenuDocumentation)

package ssip.ssip;

import android.app.Fragment;
import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.Spinner;
import android.widget.TextView;

public class MenuDocumentation extends Fragment {

    View rootview;
    private Button btn_search;

    ArrayAdapter adapterSpinner_1;
    Spinner spin1;
    String spn_1_Selected_item;
    String[] spinn_marque = {"Veuillez choisir une marque","DEF"};
    TextView txtdocumentation;

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        rootview = inflater.inflate(R.layout.activity_menu_documentation, container, false);

        btn_search = (Button) rootview.findViewById(R.id.btn_search);
        spin1 = (Spinner) rootview.findViewById(R.id.spin1);
        txtdocumentation = (TextView) rootview.findViewById(R.id.txtdocumentation);

        adapterSpinner_1 = new ArrayAdapter(getActivity(),android.R.layout.simple_spinner_dropdown_item,spinn_marque);
        spin1.setAdapter(adapterSpinner_1);
        spin1.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                spn_1_Selected_item = parent.getItemAtPosition(position).toString();

                if (spn_1_Selected_item.equals("Veuillez choisir une marque"))
                    txtdocumentation.setText("");

                if (spn_1_Selected_item.equals("DEF"))
                    btn_search.setOnClickListener(new View.OnClickListener() {
                        public void onClick(View v) {
                            Intent intent = new Intent(getActivity(), DocumentationDef.class);
                            startActivity(intent);
                        }
                    });
            }
            @Override
            public void onNothingSelected(AdapterView<?> parent) {
            }
        });
        return rootview;
    }
}

我的代码(DocumentationDef)

package ssip.ssip;

import android.app.Fragment;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.Spinner;
import android.widget.TextView;

public class DocumentationDef extends Fragment {

    View rootview;
    private Button btn_search;

    ArrayAdapter adapterSpinner_1;
    Spinner spin1;
    String spn_1_Selected_item;
    String[] spinn_element = {"Veuillez choisir un élément","RAPPORT ASSOCIATION"};
    TextView tv1;
    TextView tv2;

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        rootview = inflater.inflate(R.layout.activity_documentation_def, container, false);

        btn_search = (Button) rootview.findViewById(R.id.btn_search);
        spin1 = (Spinner) rootview.findViewById(R.id.spin1);
        tv1 = (TextView) rootview.findViewById(R.id.tv1);
        tv2 = (TextView) rootview.findViewById(R.id.tv2);

        adapterSpinner_1 = new ArrayAdapter(getActivity(),android.R.layout.simple_spinner_dropdown_item,spinn_element);
        spin1.setAdapter(adapterSpinner_1);
        spin1.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                spn_1_Selected_item = parent.getItemAtPosition(position).toString();

                if (spn_1_Selected_item.equals("Veuillez choisir un élément"))
                    tv1.setText("");
                    tv2.setText("");

                if (spn_1_Selected_item.equals("RAPPORT ASSOCIATION")){
                    tv1.setText("FORTE S");
                    tv2.setText("RAPPORT");
                    btn_search.setOnClickListener(new View.OnClickListener() {
                        public void onClick(View v) {
                            String url = "http://google.fr";
                            Intent i = new Intent(Intent.ACTION_VIEW);
                            i.setData(Uri.parse(url));
                            startActivity(i);
                        }
                    });
                }
            }
            @Override
            public void onNothingSelected(AdapterView<?> parent) {
            }
        });
        return rootview;
    }
}

我的日志

09-25 20:07:28.965 23029-23029/ssip.ssip D/ViewRootImpl: ViewPostImeInputStage processPointer 0
09-25 20:07:29.045 23029-23029/ssip.ssip D/ViewRootImpl: ViewPostImeInputStage processPointer 1
09-25 20:07:29.045 23029-23029/ssip.ssip I/Timeline: Timeline: Activity_launch_request id:ssip.ssip time:78837586
09-25 20:07:29.075 23029-23029/ssip.ssip D/AndroidRuntime: Shutting down VM
09-25 20:07:29.085 23029-23029/ssip.ssip E/AndroidRuntime: FATAL EXCEPTION: main
Process: ssip.ssip, PID: 23029
java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{ssip.ssip/ssip.ssip.DocumentationDef}: java.lang.ClassCastException: ssip.ssip.DocumentationDef cannot be cast to android.app.Activity
   at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3094)
   at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3350)
   at android.app.ActivityThread.access$1100(ActivityThread.java:222)
   at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1795)
   at android.os.Handler.dispatchMessage(Handler.java:102)
   at android.os.Looper.loop(Looper.java:158)
   at android.app.ActivityThread.main(ActivityThread.java:7229)
   at java.lang.reflect.Method.invoke(Native Method)
   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)
Caused by: java.lang.ClassCastException: ssip.ssip.DocumentationDef cannot be cast to android.app.Activity
   at android.app.Instrumentation.newActivity(Instrumentation.java:1095)
   at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3084)
   at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3350) 
   at android.app.ActivityThread.access$1100(ActivityThread.java:222) 
   at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1795) 
   at android.os.Handler.dispatchMessage(Handler.java:102) 
   at android.os.Looper.loop(Looper.java:158) 
   at android.app.ActivityThread.main(ActivityThread.java:7229) 
   at java.lang.reflect.Method.invoke(Native Method) 
   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230) 
   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120) 

解决方案

if (spn_1_Selected_item.equals("DEF"))
                    btn_search.setOnClickListener(new View.OnClickListener() {
                        public void onClick(View v) {
                            FragmentManager fragmentManager=getFragmentManager();
                            FragmentTransaction transaction=fragmentManager.beginTransaction();
                            DocumentationDef DocumentationDef = new DocumentationDef();
                            transaction.replace(R.id.content_frame, DocumentationDef);
                            transaction.commit();
                        }
                    });

Answer 1

DocumentationDef2 是一个 fragment ，因为它扩展了一个 fragment 。你的代码新的 Intent (getActivity()，DocumentationDef.class)；不管用。使用 FragmentManager 和 FragmentTransactions 将 MenuDocumentation fragment 替换为 DocumentationDef2。或者创建一个新的 Activity DocumentationDefActivity 并将 fragment 放在 DocumentationDefActivity