尝试计算以下代码的百分比， 代码说明：增强的for循环是来自外部mysql数据库的int编号列表。 if语句为从数据库接收到的int分配1、0或-1。
基本上，我想将所有的1加起来并除以for循环中的总数，并显示一个百分比。有人可以帮我这个吗。
/**
* Float variable which contains a percentage of positive moods recorded by the user.
*/
float percentage;
/**
* Float Variable which contains the total number of positive moods recorded by the user.
*/
float total;
/**
* Float variable which contains the mood number which is transferred from the MYSQL database.
*/
float val;
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
// Used for debugging purposed - displays string in the logcat
Log.d(TAG, "onCreateView: Starting to Create LineChart");
// Used to get the users ID from the stored shared preferences
loginPref = getContext().getSharedPreferences("loginPref", Context.MODE_PRIVATE);
// Displays the layout fragment_mood_log_line_graph.xml file
View view = inflater.inflate(R.layout.fragment_mood_log_line_graph, container, false);
// Initialises the pieChart view
mLineChart = view.findViewById(R.id.lineGraph);
// Method call to getPieChart();
getLineGraph();
moodLogTitle1 = view.findViewById(R.id.moodLogTitle);
moodLogTitle1.setText("moodlog"+percentage);
// Initialises all of the above on screen.
return view;
}
@Override
public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
}
/**
* Method whichs contains the linegraph
*/
private void getLineGraph() {
// Used for debugging purposes.
Log.d(TAG, "getLineChart: GetLineChart Method");
// Declare the userID which is obtained from the shared preferences.
final int userId = loginPref.getInt("userId", 0);
// Retrofit call to the MYSQL server.
Call<List<MoodLogLineGraph>> call = RetrofitClient.getInstance().getApi().moodLogLineGraph(userId);
call.enqueue(new Callback<List<MoodLogLineGraph>>() {
@Override
public void onResponse(Call<List<MoodLogLineGraph>> call, Response<List<MoodLogLineGraph>> response) {
// All JSON entries form the MYSQL server are parsed into an ArrayList.
ArrayList<Entry> yVals = new ArrayList<Entry>();
// For loop which dynamically adds all entries to the ArrayList
// response.body() contains the JSON parsed from the database. The JSON
// contains all the information requested from the database such as moodId,
// moodName, posted(date) etc.
// Getters are used to select specific pieces of information form the JSON array.
for (MoodLogLineGraph moodLogList : response.body()) {
// The getter .getMoodBefore contains an int between 1-11. These ints represent
// the mood the user has inputted to the database i.e 1=happy, 11= Depressed etc.
// The float val is used to store the integer so it can used in a LineGraph.
val = (float) moodLogList.getMoodBefore();
// The ints 1-11 which are received form the MYSQL database are then
// manually assigned a 1, 0 or -1.
// 1 = positive mood.
// 0 = Neutral mood.
// -1 = Negative mood.
// These values are then uses to plot a simple LineGraph showing increases and
// decreases in the users mood.
if ((moodLogList.getMoodBefore() == 1) || (moodLogList.getMoodBefore() == 2) || (moodLogList.getMoodBefore() == 3) || (moodLogList.getMoodBefore() == 4) ) {
// If the JSON contains a 1-4 it is assigned the value 1 which represents
// a positive mood on the LineGraph
val = 1;
// If a positive mood is recorded 1 is added to the total variable.
total++;
}
if ((moodLogList.getMoodBefore() == 8) || (moodLogList.getMoodBefore() == 9) || (moodLogList.getMoodBefore() == 10) || (moodLogList.getMoodBefore() == 5) ) {
// If the JSON contains an 5, 8. 9, or 10 it is assigned the value 0 which represents
// a neutral mood on the LineGraph
val = 0;
}
if ((moodLogList.getMoodBefore() == 6) || (moodLogList.getMoodBefore() == 7) || (moodLogList.getMoodBefore() == 11) ) {
// If the JSON contains an 6, 7. or 11 it is assigned the value -1 which represents
// a negative mood on the LineGraph
val = -1;
}
// Takes the total of positive moods i.e. 1's and divides them by the entire list received
// from the MYSQL database to work out a percentage total of positive moods.
percentage = total / response.body().size();
// Obtains the date the mood was recorded from the MYSQL database.
float date = (float) moodLogList.getDay();
// Adds the values and dates to the LineGraph ArrayList.
yVals.add(new Entry(date, val));
}
** Just to be clear the response.body() is the MYSQL JSON which is a long list of ints ranging from 1-11.
These ints are assigned a value of 1. 0 or -1 for the purpose of a linegraph. Thats why theres 11 if statements, assigning each int from the MYSQL to a 1, 0 or -1.
I need to total all the ints from the respnse.body() aka the mysql list and work out how many of them have a 1 value. Then display this value as a percentage.
答案 0 :(得分：1)
更改了代码以反映我相信您的发言。 response.body（）并非总是 一个数字，而是为您提供了不正确的百分比。
int totalInts = 0;
int positiveMoods = 0;
ArrayList<Entry> yVals = new ArrayList<Entry>();
for (MoodLogLineGraph moodLogList : response.body()) {
// Obtains the date the mood was recorded from the MYSQL database.
float date = (float) moodLogList.getDay();
if (moodLogList.getMoodBefore() >= 1 && moodLogList.getMoodBefore() <= 11)
{
totalInts++;
if (moodLogList.getMoodBefore() >= 1 && moodLogList.getMoodBefore() <= 4)
{
yVals.add(date, 1);
positiveMoods++;
}
if (moodLogList.getMoodBefore() == 6 || moodLogList.getMoodBefore() == 7 || moodLogList.getMoodBefore() == 11)
yVals.add(date, -1);
if (moodLogList.getMoodBefore() == 5 || (moodLogList.getMoodBefore() => 8 && moodLogList.getMoodBefore() <= 10))
yVals.add(date, 0);
}
float percentage = positiveMoods / totalInts;