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我想建立自己的定製相機應用程序我已經通過Android開發人員組瞭解如何編碼整個應用程序，但一旦我啓動相機它崩潰我不知道是什麼問題，這裏是我的代碼：Android定製相機應用程序崩潰，因爲它開始「不幸中止」
package com.example.tapeit;
import java.io.*;
import java.text.SimpleDateFormat;
import java.util.Date;
import android.app.Activity;
import android.content.Context;
import android.content.pm.PackageManager;
import android.hardware.Camera;
import android.hardware.Camera.PictureCallback;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore.Files.FileColumns;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.FrameLayout;
public class CameraActivity extends Activity implements Camera.PictureCallback {
private Camera mCamera;
private CameraPreview mPreview;
String TAG = "TapeIt";
public static final int MEDIA_TYPE_IMAGE = 1;
Button captureButton;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.preview_layout);
mCamera = getCameraInstance();
mPreview = new CameraPreview(this, mCamera);
FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);
preview.addView(preview);
captureButton = (Button) findViewById(R.id.button_capture);
captureButton.setOnClickListener(
new View.OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
mCamera.takePicture(null, null, mPicture);
}
});
}
private boolean checkCameraHardware(Context context){
if(context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA)){
return true;
}else{
return false;
}
}
public static Camera getCameraInstance() {
// TODO Auto-generated method stub
Camera c = null;
try {
c = Camera.open();
} catch (Exception e) {
}
return c;
}
private PictureCallback mPicture = new PictureCallback() {
@Override
public void onPictureTaken(byte[] data, Camera camera) {
// TODO Auto-generated method stub
File pictureFile = getOutputMediaFile(MEDIA_TYPE_IMAGE);
if (pictureFile == null){
Log.d(TAG, "Error creating media file, check storage permissions: ");
return;
}
try {
FileOutputStream fos = new FileOutputStream(pictureFile);
fos.write(data);
fos.close();
} catch (FileNotFoundException e) {
Log.d(TAG, "File not found: " + e.getMessage());
} catch (IOException e) {
Log.d(TAG, "Error accessing file: " + e.getMessage());
}
}
};
private static File getOutputMediaFile(int mediaTypeImage) {
// TODO Auto-generated method stub
File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), "CameraApp");
if(! mediaStorageDir.exists()){
if(! mediaStorageDir.mkdirs()){
Log.d("MyCameraApp", "failed to create directory");
return null;
}
}
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
File mediaFile = new File(mediaStorageDir.getPath() + File.separator +"IMG_"+ timeStamp + ".jpg");
return mediaFile;
}
@Override
public void onPictureTaken(byte[] data, Camera camera) {
// TODO Auto-generated method stub
File pictureFile = getOutputMediaFile(MEDIA_TYPE_IMAGE);
if (pictureFile == null){
Log.d(TAG, "Error creating media file, check storage permissions: ");
return;
}
try {
FileOutputStream fos = new FileOutputStream(pictureFile);
fos.write(data);
fos.close();
} catch (FileNotFoundException e) {
Log.d(TAG, "File not found: " + e.getMessage());
} catch (IOException e) {
Log.d(TAG, "Error accessing file: " + e.getMessage());
}
}
private void releaseCamera(){
if (mCamera != null){
mCamera.release(); // release the camera for other applications
mCamera = null;
}
}
}
這裏是我的預覽類：
package com.example.tapeit;
import java.io.IOException;
import android.content.Context;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.hardware.Camera;
public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback{
private Camera mCamera;
private SurfaceHolder mHolder;
String TAG = "TapeIt";
public CameraPreview (Context context, Camera camera){
super(context);
mCamera = camera;
mHolder = getHolder();
mHolder.addCallback(this);
}
public void surfaceCreated(SurfaceHolder holder){
try{
mCamera.setPreviewDisplay(holder);
mCamera.startPreview();
}catch(IOException e){
Log.d(TAG, "Error setting camera preview" + e.getMessage());
}
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
// TODO Auto-generated method stub
if(mHolder.getSurface() == null){
return;
}
try{
mCamera.stopPreview();
}catch(Exception e){
}
//You should make here changes when the device is rotated or when any other change
// set preview size and make any resize, rotate or
// reformatting changes here
//mCamera.getParameters().getSupportedPreviewSizes();
try{
mCamera.setPreviewDisplay(holder);
mCamera.startPreview();
}catch(IOException e){
Log.d(TAG, "Error setting camera preview" + e.getMessage());
}
}
@Override
public void surfaceDestroyed(SurfaceHolder arg0) {
// TODO Auto-generated method stub
}
}
我的清單在這裏使用所有permision它們分別是：
<uses-permission android:name="android.permission.CAMERA"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.RECORD_AUDIO" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-feature android:name="android.hardware.camera" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.tapeit.CameraActivity"
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>
我在控制檯logcat中被張貼在這裏：
04-04 11:19:32.010: D/AndroidRuntime(21270): Shutting down VM
04-04 11:19:32.010: W/dalvikvm(21270): threadid=1: thread exiting with uncaught exception (group=0x40eb72a0)
04-04 11:19:32.010: E/AndroidRuntime(21270): FATAL EXCEPTION: main
04-04 11:19:32.010: E/AndroidRuntime(21270): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.tapeit/com.example.tapeit.CameraActivity}: java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first.
04-04 11:19:32.010: E/AndroidRuntime(21270): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2092)
04-04 11:19:32.010: E/AndroidRuntime(21270): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2117)
04-04 11:19:32.010: E/AndroidRuntime(21270): at android.app.ActivityThread.access$700(ActivityThread.java:134)
04-04 11:19:32.010: E/AndroidRuntime(21270): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1218)
04-04 11:19:32.010: E/AndroidRuntime(21270): at android.os.Handler.dispatchMessage(Handler.java:99)
04-04 11:19:32.010: E/AndroidRuntime(21270): at android.os.Looper.loop(Looper.java:137)
04-04 11:19:32.010: E/AndroidRuntime(21270): at android.app.ActivityThread.main(ActivityThread.java:4867)
04-04 11:19:32.010: E/AndroidRuntime(21270): at java.lang.reflect.Method.invokeNative(Native Method)
04-04 11:19:32.010: E/AndroidRuntime(21270): at java.lang.reflect.Method.invoke(Method.java:511)
04-04 11:19:32.010: E/AndroidRuntime(21270): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1007)
04-04 11:19:32.010: E/AndroidRuntime(21270): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:774)
04-04 11:19:32.010: E/AndroidRuntime(21270): at dalvik.system.NativeStart.main(Native Method)
04-04 11:19:32.010: E/AndroidRuntime(21270): Caused by: java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first.
04-04 11:19:32.010: E/AndroidRuntime(21270): at android.view.ViewGroup.addViewInner(ViewGroup.java:3439)
04-04 11:19:32.010: E/AndroidRuntime(21270): at android.view.ViewGroup.addView(ViewGroup.java:3310)
04-04 11:19:32.010: E/AndroidRuntime(21270): at android.view.ViewGroup.addView(ViewGroup.java:3255)
04-04 11:19:32.010: E/AndroidRuntime(21270): at android.view.ViewGroup.addView(ViewGroup.java:3231)
04-04 11:19:32.010: E/AndroidRuntime(21270): at com.example.tapeit.CameraActivity.onCreate(CameraActivity.java:39)
04-04 11:19:32.010: E/AndroidRuntime(21270): at android.app.Activity.performCreate(Activity.java:5047)
04-04 11:19:32.010: E/AndroidRuntime(21270): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1094)
04-04 11:19:32.010: E/AndroidRuntime(21270): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2056)
04-04 11:19:32.010: E/AndroidRuntime(21270): ... 11 more
「不幸停止」是用戶的消息，開發人員正在logcat中獲得一個不錯的堆棧跟蹤。請添加到您的問題/自己看看吧 – zapl
發佈您的LOGCAT。 –
沒有stacktrace一切都只是最好的猜測 - 我的猜測是，你得到一個空指針例外的相機對象... – Katana24