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我正在尝试在 Android 中构建一个手势应用程序。我已成功从 sd 卡中提取手势文件并将其放入我的 res/raw 文件夹中。

但是当我启动应用程序时，它意外终止。

我的代码是：

package com.example.gest;

import java.util.ArrayList;

import android.os.Bundle;
import android.app.Activity;
import android.gesture.Gesture;
import android.gesture.GestureLibraries;
import android.gesture.GestureLibrary;
import android.gesture.GestureOverlayView;
import android.gesture.GestureOverlayView.OnGesturePerformedListener;
import android.gesture.Prediction;
import android.view.Menu;
import android.widget.Toast;

public class MainActivity extends Activity implements OnGesturePerformedListener {
    GestureLibrary mLibrary;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mLibrary = GestureLibraries.fromRawResource(this, R.raw.gestures);
           if (!mLibrary.load()) {
             finish();
           }
           GestureOverlayView gestures = (GestureOverlayView) findViewById(R.id.gestures);
           gestures.addOnGesturePerformedListener(this);


    }
    public void onGesturePerformed(GestureOverlayView overlay, Gesture gesture) {
       ArrayList<Prediction> predictions = mLibrary.recognize(gesture);
       if (predictions.size() > 0 && predictions.get(0).score > 1.0) {

         String result = predictions.get(0).name;
         if ("o".equalsIgnoreCase(result)) {
           Toast.makeText(this, "Opening the document", Toast.LENGTH_LONG).show();
         } else if ("s".equalsIgnoreCase(result)) {
           Toast.makeText(this, "Saving the document", Toast.LENGTH_LONG).show();
         }
       }

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    } 
}

我的 main.xml 文件是：

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.gest"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="15" />

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

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
<android.gesture.GestureOverlayView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/gestures"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:eventsInterceptionEnabled="true"
android:gestureStrokeType="multiple"
android:orientation="vertical" >
<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="TextView" />
</android.gesture.GestureOverlayView>

</manifest>

日志猫错误是：

11-30 09:55:05.584: E/AndroidRuntime(5031): FATAL EXCEPTION: main
11-30 09:55:05.584: E/AndroidRuntime(5031): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.gest/com.example.gest.MainActivity}: java.lang.NullPointerException
11-30 09:55:05.584: E/AndroidRuntime(5031):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2059)
11-30 09:55:05.584: E/AndroidRuntime(5031):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
11-30 09:55:05.584: E/AndroidRuntime(5031):     at android.app.ActivityThread.access$600(ActivityThread.java:130)
11-30 09:55:05.584: E/AndroidRuntime(5031):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
11-30 09:55:05.584: E/AndroidRuntime(5031):     at android.os.Handler.dispatchMessage(Handler.java:99)
11-30 09:55:05.584: E/AndroidRuntime(5031):     at android.os.Looper.loop(Looper.java:137)
11-30 09:55:05.584: E/AndroidRuntime(5031):     at android.app.ActivityThread.main(ActivityThread.java:4745)
11-30 09:55:05.584: E/AndroidRuntime(5031):     at java.lang.reflect.Method.invokeNative(Native Method)
11-30 09:55:05.584: E/AndroidRuntime(5031):     at java.lang.reflect.Method.invoke(Method.java:511)
11-30 09:55:05.584: E/AndroidRuntime(5031):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
11-30 09:55:05.584: E/AndroidRuntime(5031):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
11-30 09:55:05.584: E/AndroidRuntime(5031):     at dalvik.system.NativeStart.main(Native Method)
11-30 09:55:05.584: E/AndroidRuntime(5031): Caused by: java.lang.NullPointerException
11-30 09:55:05.584: E/AndroidRuntime(5031):     at com.example.gest.MainActivity.onCreate(MainActivity.java:27)
11-30 09:55:05.584: E/AndroidRuntime(5031):     at android.app.Activity.performCreate(Activity.java:5008)
11-30 09:55:05.584: E/AndroidRuntime(5031):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
11-30 09:55:05.584: E/AndroidRuntime(5031):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023)
11-30 09:55:05.584: E/AndroidRuntime(5031):     ... 11 more
11-30 09:55:10.323: I/Process(5031): Sending signal. PID: 5031 SIG: 9

如果有人能找出原因，那就太棒了。

4

0 回答 0