Question

我设置了int[] ledPositionControl = new int[33]。但它仍然说，我有它超出范围。我做了一个println，它只向我展示了32个，在我看来，这是正确的。

任何人都可以帮我解决这个问题吗？

logcat的：

07-31 12:10:32.421: E/AndroidRuntime(22858): FATAL EXCEPTION: main
07-31 12:10:32.421: E/AndroidRuntime(22858): java.lang.ArrayIndexOutOfBoundsException: length=33; index=33
07-31 12:10:32.421: E/AndroidRuntime(22858):    at com.example.dotmatrixleddisplay.MySurfaceView.buttonPositionControl(MySurfaceView.java:100)
07-31 12:10:32.421: E/AndroidRuntime(22858):    at com.example.dotmatrixleddisplay.MySurfaceView.surfaceChanged(MySurfaceView.java:74)
07-31 12:10:32.421: E/AndroidRuntime(22858):    at android.view.SurfaceView.updateWindow(SurfaceView.java:623)
07-31 12:10:32.421: E/AndroidRuntime(22858):    at android.view.SurfaceView.access$000(SurfaceView.java:86)
07-31 12:10:32.421: E/AndroidRuntime(22858):    at android.view.SurfaceView$3.onPreDraw(SurfaceView.java:178)
07-31 12:10:32.421: E/AndroidRuntime(22858):    at android.view.ViewTreeObserver.dispatchOnPreDraw(ViewTreeObserver.java:703)
07-31 12:10:32.421: E/AndroidRuntime(22858):    at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1942)
07-31 12:10:32.421: E/AndroidRuntime(22858):    at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1108)
07-31 12:10:32.421: E/AndroidRuntime(22858):    at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4491)
07-31 12:10:32.421: E/AndroidRuntime(22858):    at android.view.Choreographer$CallbackRecord.run(Choreographer.java:755)
07-31 12:10:32.421: E/AndroidRuntime(22858):    at android.view.Choreographer.doCallbacks(Choreographer.java:585)
07-31 12:10:32.421: E/AndroidRuntime(22858):    at android.view.Choreographer.doFrame(Choreographer.java:555)
07-31 12:10:32.421: E/AndroidRuntime(22858):    at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:741)
07-31 12:10:32.421: E/AndroidRuntime(22858):    at android.os.Handler.handleCallback(Handler.java:615)
07-31 12:10:32.421: E/AndroidRuntime(22858):    at android.os.Handler.dispatchMessage(Handler.java:92)
07-31 12:10:32.421: E/AndroidRuntime(22858):    at android.os.Looper.loop(Looper.java:137)
07-31 12:10:32.421: E/AndroidRuntime(22858):    at android.app.ActivityThread.main(ActivityThread.java:4949)
07-31 12:10:32.421: E/AndroidRuntime(22858):    at java.lang.reflect.Method.invokeNative(Native Method)
07-31 12:10:32.421: E/AndroidRuntime(22858):    at java.lang.reflect.Method.invoke(Method.java:511)
07-31 12:10:32.421: E/AndroidRuntime(22858):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1043)
07-31 12:10:32.421: E/AndroidRuntime(22858):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:810)
07-31 12:10:32.421: E/AndroidRuntime(22858):    at dalvik.system.NativeStart.main(Native Method)

buttonPositionControl方法：

int offset;
int ledSizeControl;

int[] ledPositionControl = new int[33];
int ledBmpSize;
int positionControlSize;
final int  MAX_CONTROL=64;

private void buttonPositionControl() {
        //button position + led position
        int dpi;

        dpi=GraphicsMode.dpi;

        if(maxWidth<=maxHeight){//port
            if(maxWidth/dpi<2.6){
                ledSizeControl=0;
            }
            else if(maxWidth/dpi<3.25){
                ledSizeControl=4;
            }
            else{
                ledSizeControl=8;
            }

            ledBmpSize = ledBmp[0+ledSizeControl].getWidth(); 
            positionControlSize = ledBmpSize<<2;

            for(int i=0;i<=MAX_CONTROL;i++){
                ledPositionControl[i] = maxWidth/2+(i-MAX_CONTROL/2)*ledBmpSize;
                System.out.println("LEDPOSITION = "+i);
            }
            buttonPositionY = resetPositionY = 
                    ledPositionControl[MAX_CONTROL]+positionControlSize;
            buttonPositionX = ledPositionControl[2];
            resetPositionX = buttonPositionX+positionControlSize*5;


        }   
        else{//if(maxWidth<=maxHeight){land
            if(maxHeight/dpi<2.6){
                ledSizeControl=0;
            }
            else if(maxHeight/dpi<3.25){
                ledSizeControl=4;
            }           
            else{
                ledSizeControl=8;
            }

            ledBmpSize = ledBmp[0+ledSizeControl].getWidth(); 
            positionControlSize = ledBmpSize<<2;

            for(int i=0;i<=MAX_CONTROL;i++){
                ledPositionControl[i] = maxHeight/2+(i-MAX_CONTROL/2)*ledBmpSize;
            }
            buttonPositionX = resetPositionX = 
                    ledPositionControl[MAX_CONTROL]+positionControlSize;    
            buttonPositionY  =ledPositionControl[2];
            resetPositionY = buttonPositionY+positionControlSize*5;


        }//if else
        System.out.println("ledSizeControl:"+ledSizeControl);
        System.out.println("ledBmpSize"+ledBmpSize+" maxWidth/dpi"+maxWidth/dpi);
    }

Answer 1

首先，你的循环应该在i =数组长度之前结束。

for(int i=0;i<ledPositionControl.length;i++){
    ledPositionControl[i] = maxWidth/2+(i-MAX_CONTROL/2)*ledBmpSize;
    System.out.println("LEDPOSITION = "+i);
}

其次，循环后的行应为：

buttonPositionY = resetPositionY = ledPositionControl[ledPositionControl.length - 1]+positionControlSize;

不要忘记这些问题会在您的代码中出现两次。

Answer 2

试试这个

更改此

for(int i=0;i<=MAX_CONTROL;i++)

到

for(int i=0;i<MAX_CONTROL;i++)

或

for(int i=1;i<=MAX_CONTROL;i++)
    ledPositionControl[i - 1] = //your's

因为 MAX_CONTROL 值 33 如果您使用0开始 i ，我应该以0到32结束

Answer 3

尝试这一点，如果它不让我知道它肯定会帮助你

 Set MAX_CoNTROL = ledPositionControl.size();

 for(int i=0;i<MAX_CONTROL;i++){
            ledPositionControl[i] = maxHeight/2+(i-MAX_CONTROL/2)*ledBmpSize;
        }

和Remove =登录for循环使你的循环转到索引，因为你知道数组从0索引开始所以最后一个索引将是32而不是33在日志中33指的是总的eumment计数阵列。

Answer 4

你正在迭代太多。将for循环中的＆lt; =更改为直接＆lt;你应该好。此外，您尝试访问ledPositionControl [MAX_CONTROL]。那也将失败，因为那是一个超过数组的最后一个元素。

        for(int i=0;i<MAX_CONTROL;i++){
            ledPositionControl[i] = maxWidth/2+(i-MAX_CONTROL/2)*ledBmpSize;
            System.out.println("LEDPOSITION = "+i);
        }
        buttonPositionY = resetPositionY = 
                ledPositionControl[MAX_CONTROL-1]+positionControlSize;
        buttonPositionX = ledPositionControl[2];
        resetPositionX = buttonPositionX+positionControlSize*5;

我认为关键是你需要了解在一个分配有32项的数组中，你无法访问数组[32]。数组的最后一个元素是数组[31]，因为数组是基于零的，这意味着它们从0开始，最多可达到ARRAY_SIZE-1的最大索引。

ArrayIndexOutOfBounds即使它没有超出范围

4 个答案: