在 Applet 中调用函数 repaint() 后如何重新绘制？

Question

我知道 repaint() 函数不会立即重新绘制框架。但是，这里的 repaint 方法是在递归函数期间调用的，并且仅在 towerOfHanoi 函数完成后才重新绘制。在递归函数的迭代过程中，是否有每次立即调用paint函数重绘的方法？

public void actionPerformed(ActionEvent e) {
    if (e.getSource() == start) {
        num = number.getText().trim();  
        numDisks = Integer.parseInt(num);

        //start the tower of hanoi function catch block used because of the delay function
        repaint();

        height[0].changeHeight(numDisks);
        begin = true;
        towerOfHanoi(numDisks, 0, 2, 1);
        //repaint();
    }

}


//initialize the pegs; first thing called when applet starts
public void paint(Graphics g) {
    g.setColor(Color.BLUE);
    g.fillRect(20, 190, 560, 10); //base
    g.fillRect(70, 60, 10, 150); //first peg
    g.fillRect(300, 60, 10, 150); //second peg
    g.fillRect(530, 60, 10, 150); //third peg

    //create the painting based on the amount of disks, starting with the biggest disk. 
    //when this is repainted, it will draw the new disks in different pegs with different coordinates
    g.setColor(Color.RED);
    for (int i = 0; i < numDisks; i++) {
        g.fillRect(disks[i].xPos, disks[i].yPos, disks[i].width, 10);
    }
}

public void update(Graphics g) {
    paint(g);
}


public void towerOfHanoi(int N, int from, int to, int temp) {

    if (N == 1) {
        moveTo(from, to, N);
    }
    else {
        towerOfHanoi(N - 1, from, temp, to);
        moveTo(from, to, N);
        towerOfHanoi(N - 1, temp, to, from);
    }
}

//change move to function move disks from 1st stack to the 3rd stack
public void moveTo(int from, int to, int diskNum)  {        
    System.out.println(from + "->" + to);

    //adjust the disk number to match the indexing of the way I 
    //used the disk number, as an index of arrays starting from
    //the bottom up at 0.
    if (numDisks == 1) {
        if (diskNum == 1) { diskNum = 0;}
    }
    else if (numDisks == 2) {
        if (diskNum == 1) {diskNum = 1; }
        else if (diskNum == 2) {diskNum = 0; }
    }
    else if (numDisks == 3) {
        if (diskNum == 1) { diskNum = 2;}
        else if (diskNum == 2) {diskNum = 1;}
        else if (diskNum == 3) {diskNum = 0;}
    }
    else if (numDisks == 4) {
        if (diskNum == 1) { diskNum = 3;}
        else if (diskNum == 2) {diskNum = 2;}
        else if (diskNum == 3) {diskNum = 1;}
        else if (diskNum == 4) {diskNum = 0;}
    }
    else if (numDisks == 5) {
        if (diskNum == 1) { diskNum = 4;}
        else if (diskNum == 2) {diskNum = 3;}
        else if (diskNum == 3) {diskNum = 2;}
        else if (diskNum == 4) {diskNum = 1;}
        else if (diskNum == 5) {diskNum = 0;}
    }
    else if (numDisks == 6) {
        if (diskNum == 1) { diskNum = 5;}
        else if (diskNum == 2) {diskNum = 4;}
        else if (diskNum == 3) {diskNum = 3;}
        else if (diskNum == 4) {diskNum = 2;}
        else if (diskNum == 5) {diskNum = 1;}
        else if (diskNum == 6) {diskNum = 0;}
    }
    else if (numDisks == 7) {
        if (diskNum == 1) { diskNum = 6;}
        else if (diskNum == 2) {diskNum = 5;}
        else if (diskNum == 3) {diskNum = 4;}
        else if (diskNum == 4) {diskNum = 3;}
        else if (diskNum == 5) {diskNum = 2;}
        else if (diskNum == 6) {diskNum = 1;}
        else if (diskNum == 7) {diskNum = 0;}
    }   


    //diskNum += height[from].height;
    System.out.println("Disk moving is disk # " + diskNum);
    topDisk = diskNum;

    height[from].pop();
    height[to].push();

    System.out.println("Height of Peg 1: " + height[0].height);
    System.out.println("Height of Peg 2: " + height[1].height);
    System.out.println("Height of Peg 3: " + height[2].height);
    /* we can do this the hard way and calculate the xPos and yPos
     * We might just have to create the disk1 - disk7 each with its own widths, every disk 
     * has the same height. Every disk has its own xPos and yPos.
     * when we do that, we will then need to calculate the appropriate xPos for each..
     * but how do we calculate the yPos????? 
     * yPos is calculated based on the height of the pegs...
     * So now how do we calculate what the top disk number is?
     *  
    */  


    if (from == 0 && to == 1) { //adjust the new xPos
        disks[topDisk].from0to1(); //change xPos
        if (height[1].height == 0) { //adjusts the new yPos
            disks[topDisk].yPos = 175;
        } else if (height[1].height == 1) {
            disks[topDisk].yPos = 165;
        } else if (height[1].height == 2) {
            disks[topDisk].yPos = 155;
        } else if (height[1].height == 3) {
            disks[topDisk].yPos = 145;
        } else if (height[1].height == 4) {
            disks[topDisk].yPos = 135;
        } else if (height[1].height == 5) {
            disks[topDisk].yPos = 125;
        } else if (height[1].height == 6) {
            disks[topDisk].yPos = 115;
        } else if (height[1].height == 7) {
            disks[topDisk].yPos = 105;
        }
    } else if (from == 1 && to == 2) {
        disks[topDisk].from1to2();
        if (height[2].height == 0) { //adjusts the new yPos
            disks[topDisk].yPos = 175;
        } else if (height[2].height == 1) {
            disks[topDisk].yPos = 165;
        } else if (height[2].height == 2) {
            disks[topDisk].yPos = 155;
        } else if (height[2].height == 3) {
            disks[topDisk].yPos = 145;
        } else if (height[2].height == 4) {
            disks[topDisk].yPos = 135;
        } else if (height[2].height == 5) {
            disks[topDisk].yPos = 125;
        } else if (height[2].height == 6) {
            disks[topDisk].yPos = 115;
        } else if (height[2].height == 7) {
            disks[topDisk].yPos = 105;
        }
    } else if (from == 0 && to == 2) {
        disks[topDisk].from0to2();
        if (height[2].height == 0) { //adjusts the new yPos
            disks[topDisk].yPos = 175;
        } else if (height[2].height == 1) {
            disks[topDisk].yPos = 165;
        } else if (height[2].height == 2) {
            disks[topDisk].yPos = 155;
        } else if (height[2].height == 3) {
            disks[topDisk].yPos = 145;
        } else if (height[2].height == 4) {
            disks[topDisk].yPos = 135;
        } else if (height[2].height == 5) {
            disks[topDisk].yPos = 125;
        } else if (height[2].height == 6) {
            disks[topDisk].yPos = 115;
        } else if (height[2].height == 7) {
            disks[topDisk].yPos = 105;
        }
    } else if (from == 1 && to == 0) {
        disks[topDisk].from1to0();
        if (height[0].height == 0) { //adjusts the new yPos
            disks[topDisk].yPos = 175;
        } else if (height[0].height == 1) {
            disks[topDisk].yPos = 165;
        } else if (height[0].height == 2) {
            disks[topDisk].yPos = 155;
        } else if (height[0].height == 3) {
            disks[topDisk].yPos = 145;
        } else if (height[0].height == 4) {
            disks[topDisk].yPos = 135;
        } else if (height[0].height == 5) {
            disks[topDisk].yPos = 125;
        } else if (height[0].height == 6) {
            disks[topDisk].yPos = 115;
        } else if (height[0].height == 7) {
            disks[topDisk].yPos = 105;
        }
    } else if (from == 2 && to == 0) {
        disks[topDisk].from2to0();
        if (height[0].height == 0) { //adjusts the new yPos
            disks[topDisk].yPos = 175;
        } else if (height[0].height == 1) {
            disks[topDisk].yPos = 165;
        } else if (height[0].height == 2) {
            disks[topDisk].yPos = 155;
        } else if (height[0].height == 3) {
            disks[topDisk].yPos = 145;
        } else if (height[0].height == 4) {
            disks[topDisk].yPos = 135;
        } else if (height[0].height == 5) {
            disks[topDisk].yPos = 125;
        } else if (height[0].height == 6) {
            disks[topDisk].yPos = 115;
        } else if (height[0].height == 7) {
            disks[topDisk].yPos = 105;
        }
    } else if (from == 2 && to == 1) {
        disks[topDisk].from2to1();
        if (height[1].height == 0) { //adjusts the new yPos
            disks[topDisk].yPos = 175;
        } else if (height[1].height == 1) {
            disks[topDisk].yPos = 165;
        } else if (height[1].height == 2) {
            disks[topDisk].yPos = 155;
        } else if (height[1].height == 3) {
            disks[topDisk].yPos = 145;
        } else if (height[1].height == 4) {
            disks[topDisk].yPos = 135;
        } else if (height[1].height == 5) {
            disks[topDisk].yPos = 125;
        } else if (height[1].height == 6) {
            disks[topDisk].yPos = 115;
        } else if (height[1].height == 7) {
            disks[topDisk].yPos = 105;
        }
    }
    try {
        Thread.sleep(50);
    } catch(Exception ex) {

    }
    repaint();
}

Answer 1

一旦 UI 线程可用，

repaint() 发送重绘屏幕的指令。如果您还没有这样做，我建议您在不同的线程中完成所有转换，然后 repaint() 将相对快速地刷新屏幕（因为 UI 线程没有做任何事情）。

在 Applet 中调用函数 repaint() 后如何重新绘制？

How do I repaint once the function repaint() is called in an Applet?

java

applet

swing

paint

repaint