调试时出现Java.lang.NullPointerException?
这是我的一点项目代码:调试时出现Java.lang.NullPointerException?,java,eclipse,Java,Eclipse,这是我的一点项目代码: public void render(int[] pixels, int offset, int row) { for (int yTile = yOffset <<3; yTile <= (yOffset + height) >>3; yTile++) { int yMin = yTile * 8 - yOffset; int yMax = yMin + 8; if (yMin <
public void render(int[] pixels, int offset, int row) {
for (int yTile = yOffset <<3; yTile <= (yOffset + height) >>3; yTile++) {
int yMin = yTile * 8 - yOffset;
int yMax = yMin + 8;
if (yMin < 0) yMin = 0;
if (yMax > height) yMax = height;
for (int xTile = xOffset <<3; xTile <= (xOffset + width) >>3; xTile++) {
int xMin = xTile * 8 - xOffset;
int xMax = xMin + 8;
if (xMin < 0) xMin = 0;
if (xMax > width) xMax = width;
int tileIndex = (xTile &(MAP_WIDTH_MASK)) + (yTile &(MAP_WIDTH_MASK)) * MAP_WIDTH;
for (int y = yMin; y <yMax; y++) {
int sheetPixel = ((y + yOffset) & 7) * sheet.width + ((xMin + xOffset) & 7);
int tilePixel = offset + xMin + y * row;
for (int x = xMin; x < xMax; x++) {
int colour = tileIndex * 4 + sheet.pixels[sheetPixel++];
pixels[tilePixel++] = colours[colour];
}
}
}
}
}
}
您能告诉我如何修复此错误吗?在您的代码中,我没有看到
工作表
的定义。
试着改变它
int colour = tileIndex * 4 + pixels[sheetPixel++];
我假设您试图从
int[]pixels
访问作为函数调用中的参数传递的值。什么是null?床单?像素?试试看!
int colour = tileIndex * 4 + pixels[sheetPixel++];