我必须创建一个清除按钮，按下该按钮可清除屏幕上的所有图像。图像目前在一个数组中。我刚刚将数组中的内容保存到save.txt文件中。现在我需要点击load，它会在加载之前清除屏幕上的所有图像。我该怎么做？这是我的保存代码
else if (savePicture.isPointInElement(clickX, clickY)){
FileWriter fw = new FileWriter("save.txt");
for (int i = 0; i < image; i++){
if (arraysticker[image] != null){
String name;
int x,y;
name = sticker.getname();
x = sticker.getx();
y = sticker.gety();
fw.write(name + " " + x + " " + y + "\n");
}
}
fw.flush();
fw.close();
System.out.println("saved");
}
我的整个代码是
public class main {
public static void main(String[] args) throws IOException {
EZ.initialize(1644,1022);//sets page size
sticker [] arraysticker = new sticker [20];//creates an array to hold 20 sticker
EZImage backgroundPicture = EZ.addImage("background.png", EZ.getWindowWidth() / 2, EZ.getWindowHeight() / 2); //set position of background
EZImage rectanglePicture = EZ.addImage("rectangle.png", EZ.getWindowWidth() / 2, EZ.getWindowHeight () / 7); //set position of palette
EZImage hatPicture = EZ.addImage("hat.png",1* EZ.getWindowWidth() / 10, EZ.getWindowHeight () / 6); //set position of stickers
EZImage bluntPicture = EZ.addImage("blunt.png",1* EZ.getWindowWidth() / 3, EZ.getWindowHeight () / 6); //set position of stickers
EZImage dealwithitPicture = EZ.addImage("dealwithit.png",3* EZ.getWindowWidth() / 5, EZ.getWindowHeight () / 6); //set position of stickers
EZImage weedPicture = EZ.addImage("weed.png",10* EZ.getWindowWidth() / 11, EZ.getWindowHeight () / 6); //set position of stickers
EZImage savePicture = EZ.addImage("save.png", 19* EZ.getWindowWidth() / 20, 3* EZ.getWindowHeight () / 9); //set position of save button
EZImage loadPicture = EZ.addImage("load.png", 19* EZ.getWindowWidth() / 20, 4* EZ.getWindowHeight () / 9);
EZImage clearPicture = EZ.addImage("clear.png", 19* EZ.getWindowWidth() / 20, 5* EZ.getWindowHeight () / 9);
EZSound hatsound = EZ.addSound("airhorn.wav"); //imports airhorn.wav and assigns it to hatsound
EZSound bluntsound = EZ.addSound("yungdog.wav"); //import yungdog.wav and assigns it to bluntsound
EZSound dealwithitsound = EZ.addSound("sandstorm.wav"); //imports sandstorm.wav and assigns it to dealwithitsound
EZSound weedsound = EZ.addSound("weed.wav"); //imports weed.wav and assigns it to weedsound
sticker arrayhat = new sticker (20, "hat.png");
sticker arrayblunt = new sticker (20, "blunt.png");
sticker arraydealwithit = new sticker (20, "dealwithit.png");
sticker arrayweed = new sticker (20, "weed.png");
int image = 0;//declares an integer variable named image
//creates a boolean variable and sets it to false
boolean hatSoundPlay = false;
boolean bluntSoundPlay = false;
boolean dealwithitSoundPlay = false;
boolean weedSoundPlay = false;
while (true){//while it is true
if (EZInteraction.wasMouseLeftButtonReleased()){//if left button is released
int clickX = EZInteraction.getXMouse(); //get x coordinates
int clickY = EZInteraction.getYMouse();//get y coordinates
if (hatPicture.isPointInElement(clickX, clickY)){//if hat is in the x and y coordinates
bluntSoundPlay = false; //turn all sounds false
weedSoundPlay = false;
dealwithitSoundPlay = false;
if (!hatSoundPlay) { //if hatsound not play
hatsound.play(); //hatsound will play
hatSoundPlay = true; //hat sound is now true
}
}
else if(bluntPicture.isPointInElement(clickX, clickY)){//if blunt is in the x and y coordinates
hatSoundPlay = false;//turn all sounds false
weedSoundPlay = false;
dealwithitSoundPlay = false;
if (!bluntSoundPlay) {//if bluntsound not play
bluntsound.play(); //then bluntsound will play
bluntSoundPlay = true; //bluntSoundPLay is now assigned to true
}
}
else if(dealwithitPicture.isPointInElement(clickX, clickY)){//if dealwithit is in the x and y coordinates
hatSoundPlay = false;//turn all sounds false
bluntSoundPlay = false;
weedSoundPlay = false;
if (!dealwithitSoundPlay) {//if dealwithitsound not play
dealwithitsound.play(); //then dealwithitsound will pay
dealwithitSoundPlay = true; //dealwithitSoundPlay is assigned as true
}
}
else if(weedPicture.isPointInElement(clickX, clickY)){//if weed is in the x and y coordinates
dealwithitSoundPlay = false;//turn all sounds false
hatSoundPlay = false;
bluntSoundPlay = false;
if (!weedSoundPlay) {//if weedsound not play
weedsound.play(); //then weedsound will play
weedSoundPlay = true; //sets the varialbe weedSoundPlay to true
}
}
else if (backgroundPicture.isPointInElement(clickX, clickY) && !savePicture.isPointInElement(clickX, clickY)
&& !loadPicture.isPointInElement(clickX, clickY) && !clearPicture.isPointInElement(clickX, clickY)
&& !rectanglePicture.isPointInElement(clickX, clickY)){
if (hatSoundPlay){ //if hatSoundPlay is true
hatsound.play(); //and a hatsound will play
sticker sticker1 = new sticker();//creates a new sticker1
sticker1.arraysticker(hatPicture, "hat.png", clickX, clickY);//places sticker
image ++;//increments image by 1
arraysticker[image] = sticker1;//puts sticker 1 into the array
FileWriter fw = new FileWriter("save.txt");
} else if (bluntSoundPlay){ //else if bluntSound is true
bluntsound.play(); //and blunt sound will play
sticker sticker2 = new sticker();
sticker2.arraysticker(bluntPicture, "blunt.png", clickX, clickY);//places sticker
image ++;//increments image by 1
arraysticker[image] = sticker2;//puts sticker 2 into the array
}else if (dealwithitSoundPlay){ //if dealwithitsound is true
dealwithitsound.play(); //dealwithitsound will play
sticker sticker3 = new sticker();
sticker3.arraysticker(dealwithitPicture, "dealwithit.png", clickX, clickY);//places sticker
image ++;//increments image by 1
arraysticker[image] = sticker3;//puts sticker 3 into the array
}else if (weedSoundPlay){ //if weedsound is true
weedsound.play(); //weedsound will also play
sticker sticker4 = new sticker();
sticker4.arraysticker(weedPicture, "weed.png", clickX, clickY);//places sticker
image ++;//increments image by 1
arraysticker[image] = sticker4;//puts sticker 4 into the array
}
}
else if (savePicture.isPointInElement(clickX, clickY)){
FileWriter fw = new FileWriter("save.txt");
for (int i = 0; i < image; i++){
if (arraysticker[image] != null){
String name;
int x,y;
name = sticker.getname();
x = sticker.getx();
y = sticker.gety();
fw.write(name + " " + x + " " + y + "\n");
}
}
fw.flush();
fw.close();
System.out.println("saved");
}
/*else if (loadPicture.isPointInElement(clickX, clickY)){
Scanner sc = new Scanner (new File ("save.txt"));
for (int i = 0; i < image; i++){
arraysticker.removeImage(arraysticker.image1[image]);
}
}*/
}
EZ.refreshScreen();
}
}
}
答案 0 :(得分：1)
如果arraysticker不是final，那么简单的重新分配就可以了：
arraysticker = new sicker[arraysticker.length];
这假设您需要数组保持相同的大小。如果没有必要，那么创建一个空数组：
arraysticker = new sicker[0];
如果它是最终的那么你可以将所有元素归零：
Arrays.fill( arraysticker, null );
答案 1 :(得分：0)
只需将null指定给参考。
arraysticker = null; // garbage collector will take care
或
arraysticker = new sicker[arraysticker.length]; // initialized to new length
或使用
Arrays.fill(arraysticker, null);
它只是遍历每个元素并将其设置为null。这个 当然不允许你调整数组的大小（为零），如果这是什么 你的意思是“空”。
public static void fill(Object[] a,Object val)
将指定的Object引用分配给。的每个元素 指定的对象数组。
参数： a - 要填充的数组 val - 要存储在数组的所有元素中的值抛出： ArrayStoreException - 如果指定的值不是可以存储在指定数组中的运行时类型