Question

我有一个在Java中使用的匿名内部类在其他几个函数中实现，我尝试将其更改为普通类，因此可以更容易在c ++中进行转换这是我的代码，

interface CombineFunction { 
  void combine(int[] target, int[] source); 
 } 

 class CombineLocals { 
  public int[] Vector; 
  public int[] SrcVector; 
 } 

 void Combine(final BinaryMap source, final RectangleC area, final Point at, 
   final CombineFunction function) { 
  final int shift = (area.X & WordMask) - (at.X & WordMask); 
  int vectorSize = (area.Width >> WordShift) + 2; 
  CombineLocals combineLocals = new CombineLocals(); 
  combineLocals.Vector = new int[vectorSize]; 
  combineLocals.SrcVector = new int[vectorSize]; 
  ParallelForDelegate<CombineLocals> delegate = new ParallelForDelegate<CombineLocals>() { 
   @Override 
   public CombineLocals delegate(int y, CombineLocals locals) { 
    LoadLine(locals.Vector, new Point(at.X, at.Y + y), area.Width); 
    source.LoadLine(locals.SrcVector, 
      new Point(area.X, area.Y + y), area.Width); 
    if (shift >= 0) 
     ShiftLeft(locals.SrcVector, shift); 
    else 
     ShiftRight(locals.SrcVector, -shift); 
    function.combine(locals.Vector, locals.SrcVector); 
    SaveLine(locals.Vector, new Point(at.X, at.Y + y), area.Width); 
    return locals; 
   } 

   @Override 
   public CombineLocals combineResults(CombineLocals result1, 
     CombineLocals result2) { 
    return null; 
   } 
  }; 

  Parallel.For(0, area.Height, delegate, combineLocals); 
 }

由于上面给出的代码ParallelForDelegate也是另一个像匿名内部类一样使用的接口。我尝试更改代码的方法如下，

class Combine{
    BinaryMap source;
    RectangleC area;
    Point at;
    Combine(BinaryMap bm, RectangleC rc, Point p){
        source = bm;
        area = rc;
        at = p;
    }
    void combine(int[] target, int[] source){
        final int shift =(area.X & WordMask) - (at.X & WordMask); 
        int vectorSize = (area.Width >> WordShift) + 2; 
        CombineLocals combineLocals = new CombineLocals();
        combineLocals.Vector = new int[vectorSize]; 
        combineLocals.SrcVector = new int[vectorSize]; 
        Parallel.For(0, area.Height, delegate(), combineLocals);
    }
    public CombineLocals delegate(int y, CombineLocals locals, int shift){
        LoadLine(locals.Vector, new Point(at.X, at.Y + y), area.Width); 
        source.LoadLine(locals.SrcVector, 
                  new Point(area.X, area.Y + y), area.Width); 
        if (shift >= 0) 
             ShiftLeft(locals.SrcVector, shift); 
            else 
             ShiftRight(locals.SrcVector, -shift);
        combine(locals.Vector, locals.SrcVector);
        SaveLine(locals.Vector, new Point(at.X, at.Y + y), area.Width);
        return locals;
    }
}

但是，当我尝试并行调用委托函数时。对于函数我不知道要把什么作为参数。原始类取自此SDK
https://www.programcreek.com/java-api-examples/index.php?source_dir=SecugenPlugin-master/src/sourceafis/simple/Fingerprint.java#

Answer 1

函数Parallel.For需要ParallelForDelegate<CombineLocals>类型的术语。这意味着你别无选择：你必须创建ParallelForDelegate<CombineLocals>类型的东西。

如果您不想使用匿名内部类，则需要创建一个实现该接口的命名类。由于此类与原始内部类的范围不同，因此您需要找到一种传递适当值的方法。

public class CombineDelegate // Think of a better name.
implements ParallelForDelegate<CombineLocals>
{
  private final BinaryMap source;
  private final RectangleC area;
  private final Point at;
  private final CombineFunction function;

  @Override
  public CombineLocals delegate(int y, CombineLocals locals) {
    // as in your anonymous inner class
  }

  @Override
  public CombineLocals combineResults(CombineLocals result1, 
                                      CombineLocals result2) {
    // as in your anonymous inner class
  }
}

您还需要包含mutator方法和/或构造函数来设置私有字段的值。然后，您可以按如下方式实施Combine方法。

void Combine(final BinaryMap source,
             final RectangleC area,
             final Point at, 
             final CombineFunction function) {
  final int shift = (area.X & WordMask) - (at.X & WordMask); 
  // etc...
  combineLocals.SrcVector = new int[vectorSize]; 

  ParallelForDelegate<CombineLocals> delegate =
    new CombineDelegate(source, area, at, function);

  Parallel.For(0, area.Height, delegate, combineLocals); 
}

如果在C ++中实现起来太难了，那么您需要找到另一种编写代码的方法。

注意：您不应该调用Java方法Combine;改为称呼combine。

在java中将匿名类更改为普通类

1 个答案: