安卓：surfaceView不能恢复从暂停活动（） [英] Android: surfaceView can't resume activity from pause()

问题描述

我测试surfaceView，基本上仅仅指刚更改背景颜色的应用程序。

该应用程序没有问题开始，但是当我暂停活动和恢复了，应用程序被挡在了暂停（）方法循环。

这是我的code：

 导入了java.util.Random;进口android.os.Bundle;
进口android.app.Activity;
进口android.content.Context;
进口android.graphics.Canvas;
进口android.util.Log;
进口android.view.Menu;
进口android.view.SurfaceHolder;
进口android.view.SurfaceView;公共类SurfaceViewTest延伸活动{
    FastRenderView的RenderView;    @覆盖
    保护无效的onCreate（捆绑savedInstanceState）{
        super.onCreate（savedInstanceState）;
        的setContentView（R.layout.activity_surface_view_test）;
        的RenderView =新FastRenderView（本）;
        的setContentView（的RenderView）;
    }    保护无效onResume（）{
        super.onResume（）;
        renderView.resume（）;
    }    @覆盖
    保护无效的onPause（）{
        super.onPause（）;
        renderView.pause（）;
    }    公共类FastRenderView扩展SurfaceView实现Runnable {
        螺纹renderThread = NULL;
        SurfaceHolder持有人;
        挥发性布尔运行= FALSE;        随机兰特=新的随机（）; //随机数的创造者----        公共FastRenderView（上下文的背景下）{
            超级（上下文）;
            支架= getHolder（）; //＆LT;＆LT;  - 检查本声明
        }
        公共无效简历（）{
            Log.d（ZR，在恢复）;
            运行= TRUE;
            renderThread =新主题（本）;
            renderThread.start（）; //＆LT;＆LT;＆LT;  -  AVVIA IL螺纹
        }
        @覆盖
        公共无效的run（）{
            Log.d（ZR，运行）;
            而（运行）{
                尝试{
                    视频下载（500）;
                }赶上（InterruptedException的E）{
                    // TODO自动生成catch块
                    e.printStackTrace（）;
                }
                如果（！holder.getSurface（）。isValid（）的）
                    继续;
                帆布帆布= holder.lockCanvas（）;
                canvas.drawRGB（rand.nextInt（255），rand.nextInt（255），rand.nextInt（255））;
                holder.unlockCanvasAndPost（画布）;
            }
        }
        公共无效暂停（）{
            运行= FALSE;
            Log.d（ZR，在暂停）;
            而（真）{//＆LT;＆LT;＆LT;＆LT;＆LT;＆LT;＆LT;＆LT;＆LT;＆LT;＆LT;＆LT;＆LT;＆LT; CHECKKKKKK
                尝试{
                    renderThread.join（）;
                    Log.d（ZR，在暂停结束）;
                }赶上（InterruptedException的E）{
                    e.printStackTrace（）;
                }
            }
        }
    }
}
 

解决方案

的，而（真）循环无它突破将永不停止方法暂停（）。我希望像一回东西后，成功地加入了渲染线程（等到它结束）

使用的的while循环中 run（）中的挥发性声明运行应该没问题。

I am testing surfaceView, basically the app jsut changes the color of the background.

The app starts with no issue but when I "pause" the activity and "resume" it, the app is blocked in the "pause()" method loop.

this is my code:

import java.util.Random;

import android.os.Bundle;
import android.app.Activity;
import android.content.Context;
import android.graphics.Canvas;
import android.util.Log;
import android.view.Menu;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

public class SurfaceViewTest extends Activity {
    FastRenderView renderView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_surface_view_test);
        renderView= new FastRenderView(this);
        setContentView(renderView);
    }

    protected void onResume() {
        super.onResume();
        renderView.resume();
    }

    @Override
    protected void onPause() {
        super.onPause();
        renderView.pause();
    }

    public class FastRenderView extends SurfaceView implements Runnable {
        Thread renderThread=null;
        SurfaceHolder holder;
        volatile boolean running=false;

        Random rand= new Random();                      //random number creator----

        public FastRenderView(Context context) {
            super(context);
            holder=getHolder();         //<<-check the this statement
        }
        public void resume() {
            Log.d("ZR", "in resume");
            running=true;
            renderThread=new Thread(this);
            renderThread.start();   //<<<--AVVIA IL THREAD
        }
        @Override
        public void run() {
            Log.d("ZR", "in running");
            while(running){
                try {
                    Thread.sleep(500);
                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                if(!holder.getSurface().isValid())
                    continue;
                Canvas canvas = holder.lockCanvas();
                canvas.drawRGB(rand.nextInt(255), rand.nextInt(255), rand.nextInt(255));
                holder.unlockCanvasAndPost(canvas);
            }
        }
        public void pause() {
            running = false;
            Log.d("ZR", "in pause");
            while(true){ //<<<<<<<<<<<<<<CHECKKKKKK
                try {
                    renderThread.join();
                    Log.d("ZR", "in pause end");
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

解决方案

The while(true) loop without a break in it will never stop in method pause(). I would expect something like a return after succesfully joined the rendering thread (waited till it ended)

With your volatile declaration of running the while-loop in run() should be ok.

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