Android getSurfaceHolder（）.GetSurfaceName（）重新生成高度和宽度为零的矩形

我正在制作一张基本的现场壁纸。代码在运行ICS的我的“Galaxy S2（GT-I9100）”上运行良好，函数返回正确的高度和宽度值。 但当我试图在运行GB的不同设备上运行相同的apk时，“Galaxy S2（SHW-M250L）”该矩形在返回的矩形中的高度和宽度为零：

getSurfaceHolder（）.getSurfaceName（）

函数，如日志中所示

请参阅以下代码：

public void onSurfaceCreated(SurfaceHolder holder) {
    super.onSurfaceCreated(holder);
    Log.i(TAG, "onSurfaceCreated called with height: "+getSurfaceHolder().getSurfaceFrame().height());//Just for Log check
    viewThread = new ViewThread(getSurfaceHolder(), getApplicationContext());
    viewThread.setRunning(true);
    viewThread.start();
}

我关心的是，为什么它会在特定的设备上出现故障，或者我会留下一些bug？

---

提前感谢。

高度和宽度不应在onSurface created中设置。它们应该在surfacechange上设置，其中值实际上作为参数传递给函数。如果您需要在某个地方访问这些文件，那么将其保存到字段可能是有意义的。这可以在android sdk附带的示例live wall文件中看到。只需搜索livecube

以下是一个例子：

/*
 * Copyright (C) 2009 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.example.android.livecubes.cube1;

import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Rect;
import android.os.Handler;
import android.os.SystemClock;
import android.service.wallpaper.WallpaperService;
import android.util.Log;
import android.view.MotionEvent;
import android.view.SurfaceHolder;

/*
 * This animated wallpaper draws a rotating wireframe cube.
 */
public class CubeWallpaper1 extends WallpaperService {

    private final Handler mHandler = new Handler();

    @Override
    public void onCreate() {
        super.onCreate();
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
    }

    @Override
    public Engine onCreateEngine() {
        return new CubeEngine();
    }

    class CubeEngine extends Engine {

        private final Paint mPaint = new Paint();
        private float mOffset;
        private float mTouchX = -1;
        private float mTouchY = -1;
        private long mStartTime;
        private float mCenterX;
        private float mCenterY;

        private final Runnable mDrawCube = new Runnable() {
            public void run() {
                drawFrame();
            }
        };
        private boolean mVisible;

        CubeEngine() {
            // Create a Paint to draw the lines for our cube
            final Paint paint = mPaint;
            paint.setColor(0xffffffff);
            paint.setAntiAlias(true);
            paint.setStrokeWidth(2);
            paint.setStrokeCap(Paint.Cap.ROUND);
            paint.setStyle(Paint.Style.STROKE);

            mStartTime = SystemClock.elapsedRealtime();
        }

        @Override
        public void onCreate(SurfaceHolder surfaceHolder) {
            super.onCreate(surfaceHolder);

            // By default we don't get touch events, so enable them.
            setTouchEventsEnabled(true);
        }

        @Override
        public void onDestroy() {
            super.onDestroy();
            mHandler.removeCallbacks(mDrawCube);
        }

        @Override
        public void onVisibilityChanged(boolean visible) {
            mVisible = visible;
            if (visible) {
                drawFrame();
            } else {
                mHandler.removeCallbacks(mDrawCube);
            }
        }

        @Override
        public void onSurfaceChanged(SurfaceHolder holder, int format, int width, int height) {
            super.onSurfaceChanged(holder, format, width, height);
            // store the center of the surface, so we can draw the cube in the right spot
            mCenterX = width/2.0f;
            mCenterY = height/2.0f;
            drawFrame();
        }

        @Override
        public void onSurfaceCreated(SurfaceHolder holder) {
            super.onSurfaceCreated(holder);
        }

        @Override
        public void onSurfaceDestroyed(SurfaceHolder holder) {
            super.onSurfaceDestroyed(holder);
            mVisible = false;
            mHandler.removeCallbacks(mDrawCube);
        }

        @Override
        public void onOffsetsChanged(float xOffset, float yOffset,
                float xStep, float yStep, int xPixels, int yPixels) {
            mOffset = xOffset;
            drawFrame();
        }

        /*
         * Store the position of the touch event so we can use it for drawing later
         */
        @Override
        public void onTouchEvent(MotionEvent event) {
            if (event.getAction() == MotionEvent.ACTION_MOVE) {
                mTouchX = event.getX();
                mTouchY = event.getY();
            } else {
                mTouchX = -1;
                mTouchY = -1;
            }
            super.onTouchEvent(event);
        }

        /*
         * Draw one frame of the animation. This method gets called repeatedly
         * by posting a delayed Runnable. You can do any drawing you want in
         * here. This example draws a wireframe cube.
         */
        void drawFrame() {
            final SurfaceHolder holder = getSurfaceHolder();

            Canvas c = null;
            try {
                c = holder.lockCanvas();
                if (c != null) {
                    // draw something
                    drawCube(c);
                    drawTouchPoint(c);
                }
            } finally {
                if (c != null) holder.unlockCanvasAndPost(c);
            }

            // Reschedule the next redraw
            mHandler.removeCallbacks(mDrawCube);
            if (mVisible) {
                mHandler.postDelayed(mDrawCube, 1000 / 25);
            }
        }

        /*
         * Draw a wireframe cube by drawing 12 3 dimensional lines between
         * adjacent corners of the cube
         */
        void drawCube(Canvas c) {
            c.save();
            c.translate(mCenterX, mCenterY);
            c.drawColor(0xff000000);
            drawLine(c, -400, -400, -400,  400, -400, -400);
            drawLine(c,  400, -400, -400,  400,  400, -400);
            drawLine(c,  400,  400, -400, -400,  400, -400);
            drawLine(c, -400,  400, -400, -400, -400, -400);

            drawLine(c, -400, -400,  400,  400, -400,  400);
            drawLine(c,  400, -400,  400,  400,  400,  400);
            drawLine(c,  400,  400,  400, -400,  400,  400);
            drawLine(c, -400,  400,  400, -400, -400,  400);

            drawLine(c, -400, -400,  400, -400, -400, -400);
            drawLine(c,  400, -400,  400,  400, -400, -400);
            drawLine(c,  400,  400,  400,  400,  400, -400);
            drawLine(c, -400,  400,  400, -400,  400, -400);
            c.restore();
        }

        /*
         * Draw a 3 dimensional line on to the screen
         */
        void drawLine(Canvas c, int x1, int y1, int z1, int x2, int y2, int z2) {
            long now = SystemClock.elapsedRealtime();
            float xrot = ((float)(now - mStartTime)) / 1000;
            float yrot = (0.5f - mOffset) * 2.0f;
            float zrot = 0;

            // 3D transformations

            // rotation around X-axis
            float newy1 = (float)(Math.sin(xrot) * z1 + Math.cos(xrot) * y1);
            float newy2 = (float)(Math.sin(xrot) * z2 + Math.cos(xrot) * y2);
            float newz1 = (float)(Math.cos(xrot) * z1 - Math.sin(xrot) * y1);
            float newz2 = (float)(Math.cos(xrot) * z2 - Math.sin(xrot) * y2);

            // rotation around Y-axis
            float newx1 = (float)(Math.sin(yrot) * newz1 + Math.cos(yrot) * x1);
            float newx2 = (float)(Math.sin(yrot) * newz2 + Math.cos(yrot) * x2);
            newz1 = (float)(Math.cos(yrot) * newz1 - Math.sin(yrot) * x1);
            newz2 = (float)(Math.cos(yrot) * newz2 - Math.sin(yrot) * x2);

            // 3D-to-2D projection
            float startX = newx1 / (4 - newz1 / 400);
            float startY = newy1 / (4 - newz1 / 400);
            float stopX =  newx2 / (4 - newz2 / 400);
            float stopY =  newy2 / (4 - newz2 / 400);

            c.drawLine(startX, startY, stopX, stopY, mPaint);
        }

        /*
         * Draw a circle around the current touch point, if any.
         */
        void drawTouchPoint(Canvas c) {
            if (mTouchX >=0 && mTouchY >= 0) {
                c.drawCircle(mTouchX, mTouchY, 80, mPaint);
            }
        }

    }
}

---

显然，

onSurfaceChanged

在

onSurfaceCreated

之后被调用，并且它的大小可能只在后面的回调中设置。至少值得检查一下。我同意@harism在

onSurfaceCreated

之后调用

onSurfaceChanged

，但据我所知，

onSurfaceCreated

是对created

Surface

的回调，其维度应该是某物。我还验证了SurfaceHolder不是空的。感谢@Paul提供了很好的代码示例。我试图在SurfaceChanged中读取维度，但仍然发现维度为0。请查看以下区块：`public void onSurfaceChanged（SurfaceHolder holder，int-format，int-width，int-height）{super.onSurfaceChanged（holder，format，width，height）；Log.i（标记，“onSurfaceChanged”调用：“+holder.getSurfaceFrame（）.height（））；}'如果我错了，请纠正我。它也将被设置的高度作为参数宽度和高度传递到函数中。您不需要执行holder.getSurfaceFrame（）.height（），只需执行Log.i（标记“onSurfaceChanged”称为“+height”）；这应该行得通！我理解@Paul，他们都是一样的，我写这篇文章是为了清楚。是的，在这两种情况下，我得到了相同的值，即0。