Android应用程序活动无法启动componentinfo

时间：2014-07-16 20:58:06

标签： android android-activity

大部分代码来自Download image and display it，所以当它没有工作时我感到很惊讶。我四处搜索，无法弄清楚

这里的＆＃34; mainactivity＆＃34; .java在这种情况下称为LleUrlEnter.java 

    package lle.imagedownloader;

import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import java.net.URL;
import android.widget.ImageView;

public class LleUrlEnter extends Activity {

    private ImgDownloadTask task;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        String imgLink = "http://imgur.com/8WzhDgI";
        task = new ImgDownloadTask();
        task.onPostExecute(task.doInBackground(imgLink));
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.lle_url_enter, 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);
    }

    private class ImgDownloadTask extends AsyncTask<String, Void, Bitmap> {


        protected Bitmap doInBackground(String...urls) {
            String link = urls[0];
            Bitmap imgBitmap = null;

            try {
                imgBitmap = BitmapFactory.decodeStream(new URL(link).openConnection().getInputStream());
                }

            catch (Exception e) {
                e.printStackTrace();
                }
            return imgBitmap;
            }


        protected void onPostExecute(Bitmap bitmapImage) {
            ImageView bitImg = (ImageView) findViewById(R.id.imageView1);
            bitImg.setImageBitmap(bitmapImage);
        }
    }
}

然后是＆＃34; main.xml＆＃34;名为activity_lle_url_enter.xml 

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".LleUrlEnter" >

<ImageView
    android:id="@+id/imageView1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:layout_centerVertical="true"
    android:layout_marginLeft="144dp" />

然后最后是android清单

    <?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="lle.imagedownloader"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="21" />

    <uses-permission android:name="android.permission.INTERNET" />


    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".LleUrlEnter"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

这就是LogCat向我展示的

07-16 16:27:29.119: E/Trace(11735): error opening trace file: No such file or directory (2)
07-16 16:27:29.166: W/System.err(11735): android.os.NetworkOnMainThreadException
07-16 16:27:29.166: W/System.err(11735):    at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1131)
07-16 16:27:29.166: W/System.err(11735):    at java.net.InetAddress.lookupHostByName(InetAddress.java:385)
07-16 16:27:29.166: W/System.err(11735):    at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236)
07-16 16:27:29.166: W/System.err(11735):    at java.net.InetAddress.getAllByName(InetAddress.java:214)
07-16 16:27:29.166: W/System.err(11735):    at libcore.net.http.HttpConnection.<init>(HttpConnection.java:70)
07-16 16:27:29.166: W/System.err(11735):    at libcore.net.http.HttpConnection.<init>(HttpConnection.java:50)
07-16 16:27:29.166: W/System.err(11735):    at libcore.net.http.HttpConnection$Address.connect(HttpConnection.java:340)
07-16 16:27:29.166: W/System.err(11735):    at libcore.net.http.HttpConnectionPool.get(HttpConnectionPool.java:87)
07-16 16:27:29.166: W/System.err(11735):    at libcore.net.http.HttpConnection.connect(HttpConnection.java:128)
07-16 16:27:29.166: W/System.err(11735):    at libcore.net.http.HttpEngine.openSocketConnection(HttpEngine.java:315)
07-16 16:27:29.166: W/System.err(11735):    at libcore.net.http.HttpEngine.connect(HttpEngine.java:310)
07-16 16:27:29.166: W/System.err(11735):    at libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:289)
07-16 16:27:29.166: W/System.err(11735):    at libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:239)
07-16 16:27:29.166: W/System.err(11735):    at libcore.net.http.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:273)
07-16 16:27:29.166: W/System.err(11735):    at libcore.net.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:168)
07-16 16:27:29.166: W/System.err(11735):    at lle.imagedownloader.LleUrlEnter$ImgDownloadTask.doInBackground(LleUrlEnter.java:53)
07-16 16:27:29.166: W/System.err(11735):    at lle.imagedownloader.LleUrlEnter.onCreate(LleUrlEnter.java:23)
07-16 16:27:29.166: W/System.err(11735):    at android.app.Activity.performCreate(Activity.java:5058)
07-16 16:27:29.166: W/System.err(11735):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
07-16 16:27:29.166: W/System.err(11735):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2100)
07-16 16:27:29.166: W/System.err(11735):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2174)
07-16 16:27:29.166: W/System.err(11735):    at android.app.ActivityThread.access$700(ActivityThread.java:141)
07-16 16:27:29.166: W/System.err(11735):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1267)
07-16 16:27:29.166: W/System.err(11735):    at android.os.Handler.dispatchMessage(Handler.java:99)
07-16 16:27:29.166: W/System.err(11735):    at android.os.Looper.loop(Looper.java:137)
07-16 16:27:29.166: W/System.err(11735):    at android.app.ActivityThread.main(ActivityThread.java:5059)
07-16 16:27:29.166: W/System.err(11735):    at java.lang.reflect.Method.invokeNative(Native Method)
07-16 16:27:29.166: W/System.err(11735):    at java.lang.reflect.Method.invoke(Method.java:511)
07-16 16:27:29.166: W/System.err(11735):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:792)
07-16 16:27:29.166: W/System.err(11735):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:555)
07-16 16:27:29.166: W/System.err(11735):    at dalvik.system.NativeStart.main(Native Method)
07-16 16:27:29.197: D/AndroidRuntime(11735): Shutting down VM
07-16 16:27:29.197: W/dalvikvm(11735): threadid=1: thread exiting with uncaught exception (group=0x40ebd2a0)
07-16 16:27:29.197: E/AndroidRuntime(11735): FATAL EXCEPTION: main
07-16 16:27:29.197: E/AndroidRuntime(11735): java.lang.RuntimeException: Unable to start activity ComponentInfo{lle.imagedownloader/lle.imagedownloader.LleUrlEnter}: java.lang.NullPointerException
07-16 16:27:29.197: E/AndroidRuntime(11735):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2136)
07-16 16:27:29.197: E/AndroidRuntime(11735):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2174)
07-16 16:27:29.197: E/AndroidRuntime(11735):    at android.app.ActivityThread.access$700(ActivityThread.java:141)
07-16 16:27:29.197: E/AndroidRuntime(11735):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1267)
07-16 16:27:29.197: E/AndroidRuntime(11735):    at android.os.Handler.dispatchMessage(Handler.java:99)
07-16 16:27:29.197: E/AndroidRuntime(11735):    at android.os.Looper.loop(Looper.java:137)
07-16 16:27:29.197: E/AndroidRuntime(11735):    at android.app.ActivityThread.main(ActivityThread.java:5059)
07-16 16:27:29.197: E/AndroidRuntime(11735):    at java.lang.reflect.Method.invokeNative(Native Method)
07-16 16:27:29.197: E/AndroidRuntime(11735):    at java.lang.reflect.Method.invoke(Method.java:511)
07-16 16:27:29.197: E/AndroidRuntime(11735):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:792)
07-16 16:27:29.197: E/AndroidRuntime(11735):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:555)
07-16 16:27:29.197: E/AndroidRuntime(11735):    at dalvik.system.NativeStart.main(Native Method)
07-16 16:27:29.197: E/AndroidRuntime(11735): Caused by: java.lang.NullPointerException
07-16 16:27:29.197: E/AndroidRuntime(11735):    at lle.imagedownloader.LleUrlEnter$ImgDownloadTask.onPostExecute(LleUrlEnter.java:65)
07-16 16:27:29.197: E/AndroidRuntime(11735):    at lle.imagedownloader.LleUrlEnter.onCreate(LleUrlEnter.java:23)
07-16 16:27:29.197: E/AndroidRuntime(11735):    at android.app.Activity.performCreate(Activity.java:5058)
07-16 16:27:29.197: E/AndroidRuntime(11735):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
07-16 16:27:29.197: E/AndroidRuntime(11735):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2100)
07-16 16:27:29.197: E/AndroidRuntime(11735):    ... 11 more

2 个答案:

答案 0 :(得分：0)

您正在错误地调用异步任务，在主线程上运行其代码。

替换

task.onPostExecute(task.doInBackground(imgLink));

与

task.execute(imgLink);

答案 1 :(得分：0)

对于遇到类似问题的任何人，请参阅this页面并确保添加     

到应用程序的清单（在/ yourapplication / res /中找到）

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