Question

我遇到了这个方法的问题。我想用一个可以在GUI中创建的ArrayList中的对象填充TextArea。创建对象没有问题，但是当我创建另一个对象时，旧的ArrayList仍然出现在TextArea中，但实际上我只想再次显示完整的ArrayList而不会在其中发生重复。

//The code that is presenting the text in the TextArea

public void addTextBlock(double length, double width, double height) {

    shapecontrol.makeBlock(length, width, height);
    for(int i = 0; i < shapecontrol.getShapeCollection().giveCollection().size(); i++)
     {
        InfoShapeTextArea.append(shapecontrol.getShapeCollection().giveShape(i).toString() + "\n");

     } 
}

.makeBlock方法：

public void makeBlock(double length, double width, double height)
{

    Shape shape= new Block( length,  width, height);
    shapecollection.addShape(shape);

}

.getShapeCollection（）方法：

public ShapeCollection getShapeCollection() {
    return shapecollection;
}

.giveCollection（）方法：

public ArrayList<Shape> giveCollection(){
   return shapecollection;
}

.giveShape（）方法：

public Shape giveShape(int index){


  return shapecollection.get(index);     

}

Answer 1

您需要清除InfoshapeTextArea之间的addTextBlock：

public void addTextBlock(double length, double width, double height) {
    shapecontrol.makeBlock(length, width, height);
        InfoShapeTextArea.clear(); // or setText("") or whatever will clear the text area
        for(int i = 0; i < shapecontrol.getShapeCollection().giveCollection().size(); i++)
        {
            InfoShapeTextArea.append(shapecontrol.getShapeCollection().giveShape(i).toString() + "\n");
        }
}

或者只是附加最新的文本块，而不是ArrayList的全部内容，除非您有令人信服的理由继续重写相同的信息：

public void addTextBlock(double length, double width, double height) {
    shapecontrol.makeBlock(length, width, height);
    int size = shapecontrol.getShapeCollection().giveCollection().size();
    InfoShapeTextArea.append(shapecontrol.getShapeCollection().giveShape(size-1).toString() + "\n");
}

只需将Shape对象从您的makeBlock调用回复到<{1}}即可让事情更简单：

public Shape makeBlock(double length, double width, double height)
{
    Shape shape= new Block( length,  width, height);
    shapecollection.addShape(shape);
    return shape;
}

然后：

public void addTextBlock(double length, double width, double height) {
    Shape shape = shapecontrol.makeBlock(length, width, height);
    InfoShapeTextArea.append(shape.toString() + "\n");
}

使用数组中的对象填充JTextArea

1 个答案: