Android 错误，而 Camera.open()

Question

我只想尝试在 Android 上访问我的相机。我不知道如何获取错误日志，但在调用函数 Camera.open() 时出现错误。

我使用的是 SDK 示例代码，但没有用。

我还尝试在发布前将 mCamera 设置为 null。是的，我已经在 manifest.xml 中设置了权限

即使在我的 htc 上，它也无法在模拟器上运行

package com.example.android.apis.graphics;

import android.app.Activity;
import android.content.Context;
import android.hardware.Camera;
import android.os.Bundle;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.Window;
import java.io.IOException;


public class CameraPreview extends Activity {    
    private Preview mPreview;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    // Hide the window title.
    requestWindowFeature(Window.FEATURE_NO_TITLE);

    // Create our Preview view and set it as the content of our activity.
    mPreview = new Preview(this);
    setContentView(mPreview);
}

}


class Preview extends SurfaceView implements SurfaceHolder.Callback {
    SurfaceHolder mHolder;
    Camera mCamera;


Preview(Context context) {
    super(context);

    // Install a SurfaceHolder.Callback so we get notified when the
    // underlying surface is created and destroyed.
    mHolder = getHolder();
    mHolder.addCallback(this);
    mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}

public void surfaceCreated(SurfaceHolder holder) {
    // The Surface has been created, acquire the camera and tell it where
    // to draw.
    mCamera = Camera.open();
    try {
       mCamera.setPreviewDisplay(holder);
    } catch (IOException exception) {
        mCamera.release();
        mCamera = null;
        // TODO: add more exception handling logic here
    }
}

public void surfaceDestroyed(SurfaceHolder holder) {
    // Surface will be destroyed when we return, so stop the preview.
    // Because the CameraDevice object is not a shared resource, it's very
    // important to release it when the activity is paused.
    mCamera.stopPreview();
    mCamera.release();
    mCamera = null;
}

public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
    // Now that the size is known, set up the camera parameters and begin
    // the preview.
    Camera.Parameters parameters = mCamera.getParameters();
    parameters.setPreviewSize(w, h);
    mCamera.setParameters(parameters);
    mCamera.startPreview();
}

}

Answer 1

查看已接受答案中提供的代码 here .它应该可以帮助您入门。

编辑:啊，您的 logcat 错误表明您的 list 文件中没有以下行之一(末尾 </application> 元素下方:

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