下溢在安卓4.3恢复 [英] underflow in restore in android 4.3

问题描述

我收到的 IllegalStateException异常：下溢恢复异​​常，这是造成我的应用程序崩溃。 这开始的Andr​​oid 4.3更新后发生。在Android 3.0 - 4.2.x版能正常工作

在第二的异常情况

  canvas.restore（）;
 

下面给出我的绘图code

 私人无效doDraw（帆布油画）{
        如果（mTickerBackGround = NULL和放大器;！＆安培;！（mTickerBackGround.isRecycled（）））{
            canvas.drawBitmap（mTickerBackGround，0，0，NULL）;
        }
        如果（（mBitMapBuffer！= NULL））{
            canvas.save（）;
            canvas.translate（MX，0）;
            如果（！mBitMapBuffer.isRecycled（））{
                canvas.drawBitmap（mBitMapBuffer，0，0，NULL）;
            }
            canvas.restore（）;

            如果（bitMapWidth + MX＆LT; mCanvasWidth）{
                canvas.translate（bitMapWidth + MX，0）;
                如果（！mBitMapBuffer.isRecycled（））{
                    canvas.drawBitmap（mBitMapBuffer，0，0，NULL）;
                }
                canvas.restore（）;
            }

            如果（bitMapWidth + MX＆所述; = 0）{
                MX = 0;
            }否则，如果（Math.abs（MX）＆GT;（bitMapWidth））{
                MX = mCanvasWidth;
            }

            MX-= TickerConstants.SCROLLING_SMOOTHNESS *密度;;
        }
        如果（mLogo = NULL和放大器;！＆安培;！（mLogo.isRecycled（）））{
            canvas.drawBitmap（mLogo，mCanvasWidth-（60 *密度），mLogo.getHeight（）/ 6，NULL）;
        }
    }
 

我的问题是

1. 什么是这个错误的意思？
2. 在如何解决这个问题？

生成的堆栈跟踪消息。线165对应于第二canvas.restore（）

  

08-13 18：13：09.083：E / AndroidRuntime（14139）：致命异常：   螺纹506 08-13 18：13：09.083：E / AndroidRuntime（14139）：   java.lang.IllegalStateException：下溢恢复08-13   18：13：09.083：E / AndroidRuntime（14139）：在   android.graphics.Canvas.restore（本机方法）08-13 18：13：09.083：   E / AndroidRuntime（14139）：在   com.my.package.name.ticker.TickerSurfaceView $ TickerThread.doDraw（TickerSurfaceView.java:165）   08-13 18：13：09.083：E / AndroidRuntime（14139）：在   com.my.package.name.ticker.TickerSurfaceView $ TickerThread.run（TickerSurfaceView.java:128）

解决方案

该错误是在本节的code：

 如果（bitMapWidth + MX＆LT; mCanvasWidth）{
        canvas.translate（bitMapWidth + MX，0）;
        如果（！mBitMapBuffer.isRecycled（））{
            canvas.drawBitmap（mBitMapBuffer，0，0，NULL）;
        }
        canvas.restore（）;
    }
 

正在调用恢复（），而无需调用保存（）第一。你甚至不需要说调用翻译（）或者，你可以只通过x和y坐标与 drawBitmap（）电话。

I'm getting a IllegalStateException: underflow in restore exception, which is causing my application to crash. This started happening after android 4.3 update. On android 3.0 - 4.2.x it works fine.

The exception happens on the second

canvas.restore();

Given below is my drawing code

private void doDraw(Canvas canvas) {
        if(mTickerBackGround!=null && (!mTickerBackGround.isRecycled())){
            canvas.drawBitmap(mTickerBackGround, 0, 0, null);
        }
        if((mBitMapBuffer!=null)){
            canvas.save();
            canvas.translate(mX, 0);
            if(!mBitMapBuffer.isRecycled()){
                canvas.drawBitmap(mBitMapBuffer, 0, 0, null);
            }
            canvas.restore();

            if(bitMapWidth+mX<mCanvasWidth){
                canvas.translate(bitMapWidth+mX, 0);    
                if(!mBitMapBuffer.isRecycled()){
                    canvas.drawBitmap(mBitMapBuffer, 0, 0, null);
                }
                canvas.restore();                   
            }

            if(bitMapWidth+mX<=0){
                mX = 0;
            }else if(Math.abs(mX)>(bitMapWidth)){                   
                mX= mCanvasWidth; 
            }

            mX-=TickerConstants.SCROLLING_SMOOTHNESS*density;;
        }
        if(mLogo!=null && (!mLogo.isRecycled())){
            canvas.drawBitmap(mLogo, mCanvasWidth-(60*density), mLogo.getHeight()/6, null);
        }
    }

My question is

1. What is the meaning of this error?
2. How do i fix this error?

Stack trace message generated is . Line 165 corresponds to second canvas.restore()

08-13 18:13:09.083: E/AndroidRuntime(14139): FATAL EXCEPTION: Thread-506 08-13 18:13:09.083: E/AndroidRuntime(14139): java.lang.IllegalStateException: Underflow in restore 08-13 18:13:09.083: E/AndroidRuntime(14139): at android.graphics.Canvas.restore(Native Method) 08-13 18:13:09.083: E/AndroidRuntime(14139): at com.my.package.name.ticker.TickerSurfaceView$TickerThread.doDraw(TickerSurfaceView.java:165) 08-13 18:13:09.083: E/AndroidRuntime(14139): at com.my.package.name.ticker.TickerSurfaceView$TickerThread.run(TickerSurfaceView.java:128)

解决方案

The bug is in this section of your code:

    if(bitMapWidth+mX<mCanvasWidth){
        canvas.translate(bitMapWidth+mX, 0);    
        if(!mBitMapBuffer.isRecycled()){
            canvas.drawBitmap(mBitMapBuffer, 0, 0, null);
        }
        canvas.restore();                   
    }

You are calling restore() without calling save() first. You don't even need that call to translate() either, you could just pass the x and y coordinates to the drawBitmap() call.

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