Question

我在MainActivity中有这段代码：

  boolean running = true;
    @Override
    public void onClick(View v) {

        Button button = (Button)findViewById(R.id.start);
        new Thread(new Runnable() {
            public void run() {
                int secs = 1;
                while(running){
                    Utils.delay(secs, new Utils.DelayCallback() {
                        int  seconds = 0;
                        TextView licznik = (TextView)findViewById(R.id.licznik);
                        @Override
                        public void afterDelay() {
                            seconds = seconds + 1;
                            licznik.setText(Integer.toString(seconds));

                        }
                    });


                }
            }
        }).start();


    }

及其Utils类：

    import android.os.Handler;

public class Utils {

    // Delay mechanism

    public interface DelayCallback{
        void afterDelay();
    }

    public static void delay(int secs, final DelayCallback delayCallback){
        Handler handler = new Handler();
        handler.postDelayed(new Runnable() {
            @Override
            public void run() {
                delayCallback.afterDelay();
            }
        }, secs * 1000); // afterDelay will be executed after (secs*1000) milliseconds.
    }
}

我在StackOverflow上找到了这个方法，但是在点击按钮后它崩溃了我的应用程序怎么了？请帮助，如果我应该采取另一种延迟方法，请告诉我哪个错误：

java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()

Answer 1

您正在后台Handler创建一个Thread，该Looper.prepare()尚未调用Handler handler = new Handler(Looper.getMainLooper()); handler.postDelayed(new Runnable() { @Override public void run() { delayCallback.afterDelay(); } }, secs * 1000);，并且还会触发主线程的UI组件。

尝试：

while(running)

并查看是否可以解决问题。无论哪种方式，你都可能遇到问题，因为func naiveFilter(image:[[Int]], shape:[[Int]]) -> [[Int]] { let imageRows = image.count let imageCols = image.first!.count let shapeRows = shape.count let shapeCols = shape.first!.count let shapeCenterRow = shapeRows / 2 let shapeCenterCol = shapeCols / 2 let outerRowIndex = imageRows - shapeRows + shapeCenterRow let outerColIndex = imageCols - shapeCols + shapeCenterCol let shapeOffsets = shape.enumerated().flatMap{ row,rowFlags in rowFlags.enumerated().filter{$1 == 1} .map{(row - shapeCenterRow, $0.0 - shapeCenterCol) } } var maxValues = image var imageRow = 0 var imageCol = 0 var imageValue = 0 var maxValue = 0 for row in (0..<imageRows) { let innerRow = row >= shapeCenterRow && row < outerRowIndex for col in (0..<imageCols) { maxValue = 0 if innerRow && col >= shapeCenterCol && col < outerColIndex { for (rowOffset,colOffset) in shapeOffsets { imageValue = image[row+rowOffset][col+colOffset] if imageValue > maxValue { maxValue = imageValue } } } else { for (rowOffset,colOffset) in shapeOffsets { imageRow = row + rowOffset imageCol = col + colOffset guard imageRow < imageRows else { break } if imageRow >= 0 && imageCol >= 0 && imageCol < imageCols { imageValue = image[row+rowOffset][col+colOffset] if imageValue > maxValue { maxValue = imageValue } } } } if maxValue > 0 { maxValues[row][col] = maxValue } } } return maxValues }调用会在没有睡眠的情况下触发很多...

延迟崩溃了应用程序

1 个答案: