Question

我对Android应用程序开发很新。我成功签署了我的应用并安装在我的Android手机上。 4.1.2。以下代码是我的代码。我可以知道出了什么问题吗？谢谢你们/女孩：）

activity_main.xml中

<?xml version="1.0" encoding="utf-8"?> <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"
    android:id="@+id/relativeLayout1"
     >

    <Button
        android:id="@+id/buttonFlashlight"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerVertical="true"
        android:layout_centerHorizontal="true"
        android:text="Torch" />   </RelativeLayout>

MainActivity.java

package com.mkyong.android;
import android.app.Activity;
import android.content.Context;
import android.content.pm.PackageManager;
import android.hardware.Camera;
import android.hardware.Camera.Parameters;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class MainActivity extends Activity {

    //flag to detect flash is on or off
    private boolean isLighOn = false;

    private Camera camera;

    private Button button;

    @Override
    protected void onStop() {
        super.onStop();

        if (camera != null) {
            camera.release();
        }
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        button = (Button) findViewById(R.id.buttonFlashlight);

        Context context = this;
        PackageManager pm = context.getPackageManager();

        // if device support camera?
        if (!pm.hasSystemFeature(PackageManager.FEATURE_CAMERA)) {
            Log.e("err", "Device has no camera!");
            return;
        }

        camera = Camera.open();
        final Parameters p = camera.getParameters();

        button.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View arg0) {

                if (isLighOn) {

                    Log.i("info", "torch is turn off!");

                    p.setFlashMode(Parameters.FLASH_MODE_OFF);
                    camera.setParameters(p);
                    camera.stopPreview();
                    isLighOn = false;

                } else {

                    Log.i("info", "torch is turn on!");

                    p.setFlashMode(Parameters.FLASH_MODE_TORCH);

                    camera.setParameters(p);
                    camera.startPreview();
                    isLighOn = true;

                }

            }
        });

    }
}

myandroidapps Manifest

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

    <uses-sdk android:minSdkVersion="10" android:targetSdkVersion="17" />

    <uses-permission android:name="android.permission.CAMERA" />
    <uses-feature android:name="android.hardware.camera" />

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" android:allowBackup="false">
        <activity
            android:label="@string/app_name"
            android:name=".FlashLightActivity" >
            <intent-filter >
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>   </manifest>

Answer 1

您忘记在MainActivity中声明AndroidManifest.xml活动。将其添加为：

    ....
    <activity android:name=".MainActivity" />
    ....
    </application>
    ....

不幸的是myandroidapps已经停止了

1 个答案: