Java Android摄像头预览保持白色，但不会崩溃

我正在尝试用Android上的摄像头创建一个应用程序。我使用的代码，我可以在android文档中找到，在互联网上等，就像测试。 相机预览仍然是白色的，没有任何内容，但根本没有显示预览。找不到它是来自我的模拟器还是我的代码。。。我在模拟器中使用集成网络摄像头作为摄像头

需要帮忙吗

这是我的相机预览课：

package com.guillaimej.testapplication.app;

import java.io.IOException;
import android.content.Context;
import android.hardware.Camera;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

public class CameraInputView extends SurfaceView implements SurfaceHolder.Callback {
    private SurfaceHolder mHolder;
    private Camera mCamera;

    public CameraInputView(Context context, Camera camera) {
        super(context);
        mCamera = camera;

        // Install a SurfaceHolder.Callback so we get notified when the
        // underlying surface is created and destroyed.
        mHolder = getHolder();
        mHolder.addCallback(this);
        // deprecated setting, but required on Android versions prior to 3.0
        mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    }

    public void surfaceCreated(SurfaceHolder holder) {
        // The Surface has been created, now tell the camera where to draw the preview.
        try {
            mCamera.setPreviewDisplay(holder);
            mCamera.startPreview();
        } catch (IOException e) {
            System.out.println("Error setting camera preview: " + e.getMessage());
        }
    }

    public void surfaceDestroyed(SurfaceHolder holder) {
        // empty. Take care of releasing the Camera preview in your activity.
    }

    public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
        // If your preview can change or rotate, take care of those events here.
        // Make sure to stop the preview before resizing or reformatting it.

        if (mHolder.getSurface() == null){
            // preview surface does not exist
            return;
        }

        // stop preview before making changes
        try {
            mCamera.stopPreview();
        } catch (Exception e){
            // ignore: tried to stop a non-existent preview
        }

        // set preview size and make any resize, rotate or
        // reformatting changes here

        // start preview with new settings
        try {
            mCamera.setPreviewDisplay(mHolder);
            mCamera.startPreview();

        } catch (Exception e){
            System.out.println("Error starting camera preview: " + e.getMessage());
        }
    }
}

以下是我的布局：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
tools:context="com.guillaimej.testapplication.app.CameraInputActivity">

<FrameLayout
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:id="@+id/camera_layout"
    android:layout_weight="0.2">


</FrameLayout>


<ImageButton
    android:layout_width="100dp"
    android:layout_height="100dp"
    android:id="@+id/domygif"
    android:layout_gravity="center_horizontal"
    android:background="@drawable/flask"
    android:clickable="true"
    android:onClick="snapIt"
    android:layout_weight="0.0"/>


<ImageButton
    android:layout_width="60dp"
    android:layout_height="60dp"
    android:id="@+id/returnButton"
    android:layout_gravity="center_horizontal"
    android:background="@drawable/return_button"
    android:layout_weight="0.0"/>


</LinearLayout>

---

你有教程中的其他代码吗。你是否有一个getCameraInstance。。。；你的onCreate…，看起来怎么样？mCamera.open是否发生在某个地方？是的，它发生在我的主要活动中，我会尽快发布代码，谢谢！好的，我已经用我使用相机的活动代码编辑了我的帖子，谢谢！

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.guillaimej.testapplication.app" >
    <uses-sdk android:minSdkVersion="10"
        android:targetSdkVersion="10"/>

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

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

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name=".ListOfFileActivity"
            android:label="@string/title_activity_list_of_file" >
        </activity>
        <activity
            android:name=".VideoActivity"
            android:label="@string/title_activity_video" >
        </activity>
        <activity
            android:name=".CameraInputActivity"
            android:label="@string/title_activity_camera_input" >
        </activity>
    </application>

</manifest>

package com.guillaimej.testapplication.app;

import android.content.Intent;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.FrameLayout;
import android.widget.ImageButton;
import  android.hardware.Camera;
import android.hardware.Camera.PictureCallback;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.widget.Toast;
import  android.view.SurfaceView;
import android.view.SurfaceHolder;


public class CameraInputActivity extends Activity{

    private ImageButton returnButton = null;
    private ImageButton domygifButton = null;
    //private Camera camera = null;
    private CameraInputView cameraView;
    private SurfaceHolder previewHolder;

    private FrameLayout cameraLayout = null;

    // Check if the camera is free and return it
    private static Camera isCameraAvailable() {
        Camera cam = null;
        try {
            cam = Camera.open(0);
        } catch (Exception e) {

        }
        return cam;
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_camera_input);

        returnButton = (ImageButton) findViewById(R.id.returnButton);
        returnButton.setOnTouchListener(new ReturnButtonListener());

        domygifButton = (ImageButton) findViewById(R.id.domygif);

        cameraLayout = (FrameLayout) findViewById(R.id.camera_layout);

        Camera camera = isCameraAvailable();
        // Create our Preview view and set it as the content of our activity.
        cameraView = new CameraInputView(this, camera);
        cameraLayout.addView(cameraView);
    }


}