[我意识到这个主题有很多文章,并且我已经使用它们使事情发展了很多,但是我觉得我还需要一些额外的知识来克服困难,因为他们都没有演示如何在此过程中使用数组。
我正在构建一个儿童友好的数学应用程序,因此,我正在使用.png文件显示相关数字。我在drawable文件夹中有png格式的数字0-9(透明属性需要),并且仅使用数字0-9进行了测试,但是我希望应用程序的范围更广-数字> 10(也许> 100) )-但是如果我为每个数字创建一个png文件并因此希望以编程方式组合多个png文件以进行显示,然后再将其删除(如果唯一的方法是创建一个要显示的新文件),则应用程序的尺寸将会太大)。
首先,我已经将文件输入到位图数组中-
bitmapNumbers[0] = BitmapFactory.decodeResource(getResources(), R.drawable.zero);
bitmapNumbers[1] = BitmapFactory.decodeResource(getResources(), R.drawable.one);
bitmapNumbers[2] = BitmapFactory.decodeResource(getResources(), R.drawable.two);
bitmapNumbers[3] = BitmapFactory.decodeResource(getResources(), R.drawable.three);
bitmapNumbers[4] = BitmapFactory.decodeResource(getResources(), R.drawable.four);
bitmapNumbers[5] = BitmapFactory.decodeResource(getResources(), R.drawable.five);
bitmapNumbers[6] = BitmapFactory.decodeResource(getResources(), R.drawable.six);
bitmapNumbers[7] = BitmapFactory.decodeResource(getResources(), R.drawable.seven);
bitmapNumbers[8] = BitmapFactory.decodeResource(getResources(), R.drawable.eight);
bitmapNumbers[9] = BitmapFactory.decodeResource(getResources(), R.drawable.nine);
并且在活动加载时,它会调用一种方法来生成总和并将其显示给用户,然后需要用户输入,该用户需要调用另一种方法来检查答案。以下是generateSum方法-
public void generateSum () {
String stringFirst;
String stringSecond;
Bitmap[] buildFirst;
Bitmap[] buildSecond;
String newFile = "";
Random rand = new Random();
// generate first random number
firstNumber = rand.nextInt(highestNumber + 1);
stringFirst = String.valueOf(firstNumber);
int[] splitFirst = new int[stringFirst.length()];
for (int i = 0; i < stringFirst.length(); i++) {
// split number down to individual 'single-digit' elements
splitFirst[i] = Integer.parseInt(stringFirst.substring(i, i + 1));
}
// generate second random number
secondNumber = rand.nextInt(highestNumber + 1);
stringSecond = String.valueOf(secondNumber);
int[] splitSecond = new int[stringSecond.length()];
for (int i = 0; i < stringSecond.length(); i++) {
// split number down to individual 'single-number' elements
splitSecond[i] = Integer.parseInt(stringSecond.substring(i, i + 1));
}
// calculate sum answer depending on mode selected in setup
switch (sPrefs.getString("sumMethod", null)) {
case ("Addition"):
answer = firstNumber + secondNumber;
break;
case ("Subtraction"):
if (secondNumber > firstNumber) {
while (secondNumber > firstNumber) {
firstNumber = rand.nextInt(highestNumber + 1);
secondNumber = rand.nextInt(highestNumber + 1);
}
}
answer = firstNumber - secondNumber;
break;
case ("Multiplication"):
answer = firstNumber * secondNumber;
break;
default:
return;
}
// build Bitmap array based on first number generated and split
buildFirst = new Bitmap[splitFirst.length];
for (int i = 0; i < splitFirst.length; i++) {
for (int j = 0; j <= 9; j++) {
if (j == splitFirst[i]) {
// built from Bitmap array containing .png drawable resources
buildFirst[i] = bitmapNumbers[j];
}
}
}
// code to generate new merged .png file based on built arrays and .png files
Bitmap builtFirst = Bitmap.createBitmap(buildFirst[0].getWidth(), buildFirst[0].getHeight(), buildFirst[0].getConfig());
Canvas canvas = new Canvas(builtFirst);
newFile = buildFirst[0].toString();
if (buildFirst.length > 1) {
for (int i = 1; i < buildFirst.length; i++) {
canvas.drawBitmap(buildFirst[i], 0, 0, null);
canvas.drawBitmap(builtFirst, new Matrix(), null);
newFile = newFile + buildFirst[i].toString();
}
}
try {
FileOutputStream out = new FileOutputStream("android.resource://com.app.numberup/drawable/" + newFile);
builtFirst.compress(Bitmap.CompressFormat.PNG, 100, out);
imageViewFirstNumber.setImageBitmap(builtFirst);
} catch (Exception e) {
Log.i("Error caught", e.getMessage());
e.printStackTrace();
}
/*
buildSecond = new int[splitSecond.length];
for (int i = 0; i <= splitSecond.length; i++) {
for (int j = 0; j <= 9; j++) {
if (j == splitSecond[i]) {
buildSecond[i] = numbers[j];
}
}
}*/
// original code to display single numbers - worked
//imageViewFirstNumber.setImageResource(numbers[i]);
//imageViewSecondNumber.setImageResource(numbers[i]);
}
根据我的观察,这段代码至少应该在drawable目录中建立一个.png文件(如果生成的数字称为72.png。我知道这行-
imageViewFirstNumber.setImageBitmap(builtFirst);
不会显示该文件。我不确定如何引用新生成的文件,但是更大的问题是newFile不在可绘制的文件夹中查找。
我也知道-
if (buildFirst.length > 1) {
for (int i = 1; i < buildFirst.length; i++) {
canvas.drawBitmap(buildFirst[i], 0, 0, null);
canvas.drawBitmap(builtFirst, new Matrix(), null);
newFile = newFile + buildFirst[i].toString();
}
}
这只会将一个数字图像堆放在另一个数字的上面,我在想如果我使用buildFirst[i].getwidth * i
作为'left'参数会将图像放置在最后一个图像的右边,但我希望能够显示任何生成的图像,然后进行细化。目前,我只在生成总和后才显示默认数字文件。
我的错误处理程序确实在此代码行上捕获了FileNotFoundException-
Bitmap builtFirst = Bitmap.createBitmap(buildFirst[0].getWidth(), buildFirst[0].getHeight(), buildFirst[0].getConfig());
[我认为这是由于buildFirst[0]
的内容为'android.graphics.Bitmap@1852540c',其内容与[1]类似(生成了2位数字),. png文件不能完成此过程吗?如果是这样,我如何合并它们,同时保留原始.png文件的透明属性?也许有更好的方法填充原始Bitmap数组?
任何人都没有解决此图像处理步骤的指针吗?
2天的反复试验终于解决了问题。
这里没有问题,无需压缩文件或编写任何新文件,也无需使用任何位图作为模板,也无需引用新的drawable作为资源(而是仅应用创建的Bitmap变量)。]
Bitmap builtFirst = Bitmap.createBitmap(500 * splitFirst.length, 700, ARGB_8888);
Canvas canvas = new Canvas(builtFirst);
if (buildFirst.length > 1) {
for (int i = 0; i < buildFirst.length; i++) {
canvas.drawBitmap(buildFirst[i], 300 * i, 0, null);
canvas.drawBitmap(builtFirst, new Matrix(), null);
}
}
imageViewFirstNumber.setImageBitmap(builtFirst);