我正在开发自己的Android相机应用程序。我想要做的是当我打开我的应用程序时，它必须显示两个按钮，可能捕获和拍照使用相机屏幕。当我点击捕捉按钮时，我可以拍摄当前位置的图像（来自后置摄像头）。如果我点击拍照按钮，我想捕捉这张照片我想从前置摄像头拍摄照片但它显示java.lang.runtimeexception method called after release()。在这里我附上了我的代码。所以请任何人帮我解决错误。
MainActivity.java
package com.example.camera1;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.hardware.Camera;
import android.hardware.Camera.PictureCallback;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.FrameLayout;
import android.widget.ImageView;
import android.widget.Toast;
public class MainActivity extends Activity {
private Camera cameraObject;
private ShowCamera showCamera;
private ImageView pic;
private Button takePhotoButton;
FrameLayout preview;
public static Camera isCameraAvailiable(){
Camera object = null;
try {
object = Camera.open();
}
catch (Exception e){
}
return object;
}
private PictureCallback capturedIt = new PictureCallback() {
@Override
public void onPictureTaken(byte[] data, Camera camera) {
Bitmap bitmap = BitmapFactory.decodeByteArray(data , 0, data .length);
if(bitmap==null){
Toast.makeText(getApplicationContext(), "not taken", Toast.LENGTH_SHORT).show();
}
else
{
Toast.makeText(getApplicationContext(), "taken", Toast.LENGTH_SHORT).show();
}
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
takePhotoButton = (Button)findViewById(R.id.button_takephoto);
cameraObject = isCameraAvailiable();
showCamera = new ShowCamera(this, cameraObject);
preview = (FrameLayout) findViewById(R.id.camera_preview);
preview.addView(showCamera);
takePhotoButton.setOnClickListener(new OnClickListener() {
@SuppressWarnings("static-access")
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
cameraObject.stopPreview();
preview.removeView(showCamera);
cameraObject.release();
cameraObject.open(1);
showCamera = new ShowCamera(MainActivity.this, cameraObject);
preview.addView(showCamera);
}
});
}
public void snapIt(View view){
cameraObject.takePicture(null, null, capturedIt);
}
@Override
public void onPause(){
super.onPause();
if (cameraObject != null) {
cameraObject.stopPreview();
cameraObject.release();
cameraObject = null;
}
preview.removeView(showCamera);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
}
ShowCamera.java
package com.example.camera1;
import java.io.IOException;
import android.content.Context;
import android.hardware.Camera;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
public class ShowCamera extends SurfaceView implements SurfaceHolder.Callback {
private SurfaceHolder holdMe;
private Camera theCamera;
public ShowCamera(Context context,Camera camera) {
super(context);
theCamera = camera;
holdMe = getHolder();
holdMe.addCallback(this);
}
@Override
public void surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3) {
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
try {
theCamera.setDisplayOrientation(90);
theCamera.setPreviewDisplay(holder);
theCamera.startPreview();
} catch (IOException e) {
}
}
@Override
public void surfaceDestroyed(SurfaceHolder arg0) {
this.getHolder().removeCallback(this);
theCamera.stopPreview();
theCamera.release();
}
}
activity_main.xml中
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="horizontal" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="0.30"
android:orientation="vertical" >
<FrameLayout
android:id="@+id/camera_preview"
android:layout_width="fill_parent"
android:layout_height="350dp" />
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<Button
android:id="@+id/button_capture"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:onClick="snapIt"
android:text="@string/Capture" />
<Button
android:id="@+id/button_takephoto"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@+id/button_capture"
android:text="Take Photo" />
</RelativeLayout>
</LinearLayout>
</LinearLayout>
LogCat输出
05-29 12:42:56.378: E/AndroidRuntime(15990): FATAL EXCEPTION: main
05-29 12:42:56.378: E/AndroidRuntime(15990): java.lang.RuntimeException: Method called after release()
05-29 12:42:56.378: E/AndroidRuntime(15990): at android.hardware.Camera.setDisplayOrientation(Native Method)
05-29 12:42:56.378: E/AndroidRuntime(15990): at com.example.camera1.ShowCamera.surfaceCreated(ShowCamera.java:29)
05-29 12:42:56.378: E/AndroidRuntime(15990): at android.view.SurfaceView.updateWindow(SurfaceView.java:580)
05-29 12:42:56.378: E/AndroidRuntime(15990): at android.view.SurfaceView.access$000(SurfaceView.java:83)
05-29 12:42:56.378: E/AndroidRuntime(15990): at android.view.SurfaceView$3.onPreDraw(SurfaceView.java:177)
05-29 12:42:56.378: E/AndroidRuntime(15990): at android.view.ViewTreeObserver.dispatchOnPreDraw(ViewTreeObserver.java:726)
05-29 12:42:56.378: E/AndroidRuntime(15990): at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2084)
05-29 12:42:56.378: E/AndroidRuntime(15990): at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1125)
05-29 12:42:56.378: E/AndroidRuntime(15990): at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4607)
05-29 12:42:56.378: E/AndroidRuntime(15990): at android.view.Choreographer$CallbackRecord.run(Choreographer.java:747)
05-29 12:42:56.378: E/AndroidRuntime(15990): at android.view.Choreographer.doCallbacks(Choreographer.java:567)
05-29 12:42:56.378: E/AndroidRuntime(15990): at android.view.Choreographer.doFrame(Choreographer.java:536)
05-29 12:42:56.378: E/AndroidRuntime(15990): at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:733)
05-29 12:42:56.378: E/AndroidRuntime(15990): at android.os.Handler.handleCallback(Handler.java:615)
05-29 12:42:56.378: E/AndroidRuntime(15990): at android.os.Handler.dispatchMessage(Handler.java:92)
05-29 12:42:56.378: E/AndroidRuntime(15990): at android.os.Looper.loop(Looper.java:153)
05-29 12:42:56.378: E/AndroidRuntime(15990): at android.app.ActivityThread.main(ActivityThread.java:5086)
05-29 12:42:56.378: E/AndroidRuntime(15990): at java.lang.reflect.Method.invokeNative(Native Method)
05-29 12:42:56.378: E/AndroidRuntime(15990): at java.lang.reflect.Method.invoke(Method.java:511)
05-29 12:42:56.378: E/AndroidRuntime(15990): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:821)
05-29 12:42:56.378: E/AndroidRuntime(15990): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:584)
05-29 12:42:56.378: E/AndroidRuntime(15990): at dalvik.system.NativeStart.main(Native Method)
答案 0 :(得分：0)
更改 cameraObject.open（1）;
到
cameraObject = Camera.open（1）;
内部方法调用onclick（）按钮takePhotoButton。它会工作。