Question

尝试在我的应用中制作自定义SurfaceView视图时出错。

<com.example.test.CustomSurfaceView
    android:id="@+id/cameraPreview"
    android:layout_width="match_parent"
    android:layout_height="match_parent"/>

这是班级：

package com.example.test;
import android.content.Context;
import android.hardware.Camera;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import java.util.List;
public class CustomSurfaceView extends SurfaceView implements SurfaceHolder.Callback {

private static final String TAG = "CameraPreview";

private Context mContext;
private SurfaceHolder mHolder;
private Camera mCamera;
private List<Camera.Size> mSupportedPreviewSizes;
private Camera.Size mPreviewSize;

public CustomSurfaceView(Context context, Context mContext) {
    super(context);
    this.mContext = mContext;
}

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

    // supported preview sizes
    mSupportedPreviewSizes = mCamera.getParameters().getSupportedPreviewSizes();
    for(Camera.Size str: mSupportedPreviewSizes)
        Log.e(TAG, str.width + "/" + str.height);

    // 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) {
    // empty. surfaceChanged will take care of stuff
}

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) {
    Log.e(TAG, "surfaceChanged => w=" + w + ", h=" + 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 {
        Camera.Parameters parameters = mCamera.getParameters();
        parameters.setPreviewSize(mPreviewSize.width, mPreviewSize.height);
        mCamera.setParameters(parameters);
        mCamera.setDisplayOrientation(90);
        mCamera.setPreviewDisplay(mHolder);
        mCamera.startPreview();

    } catch (Exception e){
        Log.d(TAG, "Error starting camera preview: " + e.getMessage());
    }
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    final int width = resolveSize(getSuggestedMinimumWidth(), widthMeasureSpec);
    final int height = resolveSize(getSuggestedMinimumHeight(), heightMeasureSpec);

    if (mSupportedPreviewSizes != null) {
        mPreviewSize = getOptimalPreviewSize(mSupportedPreviewSizes, width, height);
    }

    if (mPreviewSize!=null) {
        float ratio;
        if(mPreviewSize.height >= mPreviewSize.width)
            ratio = (float) mPreviewSize.height / (float) mPreviewSize.width;
        else
            ratio = (float) mPreviewSize.width / (float) mPreviewSize.height;

        // One of these methods should be used, second method squishes preview slightly
        setMeasuredDimension(width, (int) (width * ratio));
        //        setMeasuredDimension((int) (width * ratio), height);
    }
}

private Camera.Size getOptimalPreviewSize(List<Camera.Size> sizes, int w, int h) {
    final double ASPECT_TOLERANCE = 0.1;
    double targetRatio = (double) h / w;

    if (sizes == null)
        return null;

    Camera.Size optimalSize = null;
    double minDiff = Double.MAX_VALUE;

    int targetHeight = h;

    for (Camera.Size size : sizes) {
        double ratio = (double) size.height / size.width;
        if (Math.abs(ratio - targetRatio) > ASPECT_TOLERANCE)
            continue;

        if (Math.abs(size.height - targetHeight) < minDiff) {
            optimalSize = size;
            minDiff = Math.abs(size.height - targetHeight);
        }
    }

    if (optimalSize == null) {
        minDiff = Double.MAX_VALUE;
        for (Camera.Size size : sizes) {
            if (Math.abs(size.height - targetHeight) < minDiff) {
                optimalSize = size;
                minDiff = Math.abs(size.height - targetHeight);
            }
        }
    }

    return optimalSize;
}
}

我得到的错误：

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.test/com.example.test.HomeActivity}: android.view.InflateException: Binary XML file line #7: Binary XML file line #7: Error inflating class com.example.test.CustomSurfaceView

我实际上在同一个xml中有另一个自定义viewpager视图，但它工作正常。知道为什么我会收到这个错误吗？我实际上在同一个xml中有另一个自定义viewpager视图，但它工作正常。知道为什么我会收到这个错误吗？

Answer 1

如果通过使用XML标记在布局中放置视图，则必须实现此构造函数：

public View(Context context, AttributeSet attrs)

Android错误从自定义视图中膨胀类

1 个答案: