package com.example.nrbapp;
import java.util.ArrayList;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.content.Context;
import android.graphics.Color;
import android.graphics.Typeface;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewGroup.LayoutParams;
import android.widget.LinearLayout;
import android.widget.ScrollView;
import android.widget.TableLayout;
import android.widget.TableRow;
import android.widget.TextView;
import android.os.Build;
public class SearchResult extends ActionBarActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Bundle extras = getIntent().getExtras();
if (extras != null) {
int check = extras.getInt("check");
ArrayList<String> K_array = extras.getStringArrayList("K_array");
}
setContentView(R.layout.activity_search_result);
LinearLayout t1 = (LinearLayout) findViewById(R.id.linear_layout);
TextView tr = new TextView(this);
//tr.setId(95);// define id that must be unique
tr.setText("TYPE:"); // set the text for the header
tr.setTextColor(Color.WHITE); // set the color
tr.setTypeface(null, Typeface.BOLD);
tr.setPadding(5, 5, 5, 5); // set the padding (if required)
t1.addView(tr);//**LINE 43**
//t1.addView(tr, new LinearLayout.LayoutParams(
// LayoutParams.FILL_PARENT,
// LayoutParams.WRAP_CONTENT));
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment()).commit();
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.search_result, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_search_result,
container, false);
return rootView;
}
}
}
获取Null Pointer Exception行：43 我评论过Line43 这是我的android项目的一部分，以获得动态线性布局 请帮我找出错误，我的完整logcat是，谢谢。
06-09 06:50:03.590: E/AndroidRuntime(3794): FATAL EXCEPTION: main
06-09 06:50:03.590: E/AndroidRuntime(3794): Process: com.example.nrbapp, PID: 3794
06-09 06:50:03.590: E/AndroidRuntime(3794): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.nrbapp/com.example.nrbapp.SearchResult}: java.lang.NullPointerException
06-09 06:50:03.590: E/AndroidRuntime(3794): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
06-09 06:50:03.590: E/AndroidRuntime(3794): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
06-09 06:50:03.590: E/AndroidRuntime(3794): at android.app.ActivityThread.access$800(ActivityThread.java:135)
06-09 06:50:03.590: E/AndroidRuntime(3794): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
06-09 06:50:03.590: E/AndroidRuntime(3794): at android.os.Handler.dispatchMessage(Handler.java:102)
06-09 06:50:03.590: E/AndroidRuntime(3794): at android.os.Looper.loop(Looper.java:136)
06-09 06:50:03.590: E/AndroidRuntime(3794): at android.app.ActivityThread.main(ActivityThread.java:5017)
06-09 06:50:03.590: E/AndroidRuntime(3794): at java.lang.reflect.Method.invokeNative(Native Method)
06-09 06:50:03.590: E/AndroidRuntime(3794): at java.lang.reflect.Method.invoke(Method.java:515)
06-09 06:50:03.590: E/AndroidRuntime(3794): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
06-09 06:50:03.590: E/AndroidRuntime(3794): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
06-09 06:50:03.590: E/AndroidRuntime(3794): at dalvik.system.NativeStart.main(Native Method)
06-09 06:50:03.590: E/AndroidRuntime(3794): Caused by: java.lang.NullPointerException
06-09 06:50:03.590: E/AndroidRuntime(3794): at com.example.nrbapp.SearchResult.onCreate(SearchResult.java:43)
06-09 06:50:03.590: E/AndroidRuntime(3794): at android.app.Activity.performCreate(Activity.java:5231)
06-09 06:50:03.590: E/AndroidRuntime(3794): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
06-09 06:50:03.590: E/AndroidRuntime(3794): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
06-09 06:50:03.590: E/AndroidRuntime(3794): ... 11 more
06-09 06:50:04.950: I/Process(3794): Sending signal. PID: 3794 SIG: 9
06-09 06:50:05.820: D/AndroidRuntime(3811): Shutting down VM
06-09 06:50:05.820: W/dalvikvm(3811): threadid=1: thread exiting with uncaught exception (group=0xb3a9eba8)
06-09 06:50:05.830: E/AndroidRuntime(3811): FATAL EXCEPTION: main
06-09 06:50:05.830: E/AndroidRuntime(3811): Process: com.example.nrbapp, PID: 3811
06-09 06:50:05.830: E/AndroidRuntime(3811): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.nrbapp/com.example.nrbapp.SearchResult}: java.lang.NullPointerException
06-09 06:50:05.830: E/AndroidRuntime(3811): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
06-09 06:50:05.830: E/AndroidRuntime(3811): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
06-09 06:50:05.830: E/AndroidRuntime(3811): at android.app.ActivityThread.access$800(ActivityThread.java:135)
06-09 06:50:05.830: E/AndroidRuntime(3811): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
06-09 06:50:05.830: E/AndroidRuntime(3811): at android.os.Handler.dispatchMessage(Handler.java:102)
06-09 06:50:05.830: E/AndroidRuntime(3811): at android.os.Looper.loop(Looper.java:136)
06-09 06:50:05.830: E/AndroidRuntime(3811): at android.app.ActivityThread.main(ActivityThread.java:5017)
06-09 06:50:05.830: E/AndroidRuntime(3811): at java.lang.reflect.Method.invokeNative(Native Method)
06-09 06:50:05.830: E/AndroidRuntime(3811): at java.lang.reflect.Method.invoke(Method.java:515)
06-09 06:50:05.830: E/AndroidRuntime(3811): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
06-09 06:50:05.830: E/AndroidRuntime(3811): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
06-09 06:50:05.830: E/AndroidRuntime(3811): at dalvik.system.NativeStart.main(Native Method)
06-09 06:50:05.830: E/AndroidRuntime(3811): Caused by: java.lang.NullPointerException
06-09 06:50:05.830: E/AndroidRuntime(3811): at com.example.nrbapp.SearchResult.onCreate(SearchResult.java:43)
06-09 06:50:05.830: E/AndroidRuntime(3811): at android.app.Activity.performCreate(Activity.java:5231)
06-09 06:50:05.830: E/AndroidRuntime(3811): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
06-09 06:50:05.830: E/AndroidRuntime(3811): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
06-09 06:50:05.830: E/AndroidRuntime(3811): ... 11 more
这是我的activity_search_result.xml
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.nrbapp.SearchResult"
tools:ignore="MergeRootFrame">
<LinearLayout
android:id="@+id/linear_layout"
android:layout_width="match_parent"
android:layout_height="39dp"
android:gravity="center_vertical">
<TextView
android:id="@+id/textView100"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="5dp"
android:textIsSelectable="true"
android:textSize="12sp"
android:textStyle="bold"
/>
</LinearLayout>
</FrameLayout>
答案 0 :(得分：1)
在onCreate()：
setContentView(R.layout.activity_search_result);
因此在activity_search_result中引用了线性布局“tr”，这就是为textview引用NPE的原因。
对于活动会发生这种情况，因为您的linearlayout可能是在片段布局中定义的（请发布fragment_search_result.xml，相应地删除或更新答案）
所以你应该将findViewById改为onCreateView，如：
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_search_result,
container, false);
//now declare linearlayout to be found in fragment_search_result.xml
LinearLayout t1 = (LinearLayout) rootView.findViewById(R.id.linear_layout);
TextView tr = new TextView(SearchResult.this);
//tr.setId(95);// define id that must be unique
tr.setText("TYPE:"); // set the text for the header
tr.setTextColor(Color.WHITE); // set the color
tr.setTypeface(null, Typeface.BOLD);
tr.setPadding(5, 5, 5, 5); // set the padding (if required)
t1.addView(tr);
return rootView;
}
答案 1 :(得分：0)
您的LinearLayout t1在哪里，在activity_search_result.xml或fragment_search_result中？那可能是错误的......