如何基于sqlite中存储的某些单个值更改MPandroidCharts中的条形颜色? [英] how to change Bar color in MPandroidCharts based on some individual value stored in sqlite?

问题描述

如果有一个SQLite可以存储3个值名称，贷方和标记.我有一个带有x-axis:names，y-axis:bunks的mpandroid条形图.我想更改单个条形颜色或基于存储在SQLite中的每个条目的信用来添加限制线.这可能吗? 我是新手，请帮帮我.

If have an SQLite which stores 3 values names,credits,bunks. I have an mpandroid bar chart with x-axis:names,y-axis:bunks. I want to change the individual bar color or add limitline based on their credits for each entry,stored in SQLite. Is this possible? I am new to this please help me out.

public class Myhelper extends SQLiteOpenHelper {
public static final String DATABASE_NAME="mydatabase.db";
    public static final String TABLE_NAME="mytable";
    public static final String COLUMN_ID="_id";
    public static final String COL_1="NAME";
    public static  final String COL_2="CREDIT";
    public  static final String COL_3="BUNKS";
    public static final String[] COLUMNS ={COLUMN_ID,COL_1,COL_2,COL_3};
    Context con;

    public Myhelper(Context context) {
        super(context, DATABASE_NAME, null, 1);
        con = context;
    }


    @Override
    public void onCreate(SQLiteDatabase db) {
        String createTable= "CREATE TABLE " + TABLE_NAME + " (" + COLUMN_ID +" INTEGER PRIMARY KEY AUTOINCREMENT, " + " NAME TEXT, CREDIT TEXT, BUNKS INTEGER )";
        db.execSQL(createTable);
        Toast.makeText(con,"table created",Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("DROP TABLE IF EXISTS "+ TABLE_NAME);
        onCreate(db);

    }
    public boolean insertData(String x,String y,int z){
        SQLiteDatabase db=this.getWritableDatabase();
        ContentValues contentValues = new ContentValues();
        contentValues.put(COL_1, String.valueOf(x));
        contentValues.put(COL_2,String.valueOf(y));
       contentValues.put(COL_3,z);
        long result = db.insert(TABLE_NAME, null, contentValues);
        if (result == -1) {
            return false;
        } else {
            return true;
        }
    }

    public ArrayList<String> queryXdata(){
        ArrayList<String> xnewdata= new ArrayList<String>();
        String query = "SELECT "+ COL_1 + " FROM " + TABLE_NAME;
        SQLiteDatabase db=this.getWritableDatabase();
        Cursor cursor= db.rawQuery(query,null);
        for (cursor.moveToFirst(); !cursor.isAfterLast(); cursor.moveToNext()){
            xnewdata.add(cursor.getString(cursor.getColumnIndex(COL_1)));
        }
        cursor.close();
        return xnewdata;

    }
    public ArrayList<Integer> queryYdata(){
        ArrayList<Integer> ynewdata= new ArrayList<Integer>();
        String query = "SELECT "+ COL_3+ " FROM " + TABLE_NAME;
        SQLiteDatabase db=this.getWritableDatabase();
        Cursor cursor= db.rawQuery(query,null);
        for (cursor.moveToFirst(); !cursor.isAfterLast(); cursor.moveToNext()){
            ynewdata.add(cursor.getInt(cursor.getColumnIndex(COL_3)));
        }
        cursor.close();
        return ynewdata;

    }
    public  ArrayList<Integer> queryZdata(){
       ArrayList<Integer> znewdata= new ArrayList<Integer>();
        String query = "SELECT "+ COL_2+ " FROM " + TABLE_NAME;
        SQLiteDatabase db=this.getWritableDatabase();
        Cursor cursor= db.rawQuery(query,null);
        for (cursor.moveToFirst(); !cursor.isAfterLast(); cursor.moveToNext()){
            znewdata.add(((cursor.getColumnIndex(COL_2))));
        }
        cursor.close();
        return znewdata;
    }

    public attendence getdetails(long id){
        SQLiteDatabase db = this.getWritableDatabase();
        String query= "SELECT" + COL_2+" FROM " + TABLE_NAME +" WHERE _id=" + id;
        Cursor cursor= db.rawQuery(query,null);
        attendence attendence1= new attendence();
        if (cursor.getCount()>0){
            cursor.moveToFirst();
            attendence1.setSubname(cursor.getString(cursor.getColumnIndex(COL_1)));
            attendence1.setCredit(cursor.getString(cursor.getColumnIndex(COL_2)));
            attendence1.setBunks(cursor.getInt(cursor.getColumnIndex(COL_3)));
        }
        return attendence1;
    }

    public void delete(long id,Context context){
        SQLiteDatabase db=this.getWritableDatabase();
        db.execSQL("DELETE FROM "+TABLE_NAME+" WHERE _id='"+id+"'");
        Toast.makeText(context,"delted",Toast.LENGTH_SHORT).show();
    }
    public List<attendence> list(String  filter){
        String query;
        if (filter.equals("")){
            query = "SELECT * FROM " + TABLE_NAME ;

        }
        else {
            query= " SELECT * FROM " + TABLE_NAME ;

        }
        List<attendence> linkedlist = new LinkedList<>();
        SQLiteDatabase db = this.getWritableDatabase();
        Cursor cursor = db.rawQuery(query,null);
        attendence attendence;
        if (cursor.moveToFirst()){
            do {
                attendence = new attendence();
                attendence.setId(cursor.getLong(cursor.getColumnIndex(COLUMN_ID)));
                attendence.setSubname(cursor.getString(cursor.getColumnIndex(COL_1)));
                attendence.setCredit(cursor.getString(cursor.getColumnIndex(COL_2)));
                attendence.setBunks(cursor.getInt(cursor.getColumnIndex(COL_3)));
                linkedlist.add(attendence);
            }
            while (cursor.moveToNext());
        }
        return linkedlist;
    }


    public int getbunk(long id) {
        SQLiteDatabase db = this.getReadableDatabase();
        Cursor cursor = db.rawQuery("SELECT * FROM " + TABLE_NAME + " WHERE " + COLUMN_ID + " = " + String.valueOf(id), null);
        int output = -1;
        if (cursor != null) {
            if (cursor.moveToFirst()) {
                output = cursor.getInt(cursor.getColumnIndex(COL_3));
            }
            cursor.close();
        }
        return output;

    }
    public int updatebunk(long id){
        SQLiteDatabase db = this.getWritableDatabase();
        int bunk = getbunk(id);
        if (bunk<0){
            Log.i("error", "updatebunk:below 0 ");

        }
        int bunkinc= ++bunk;
        ContentValues contentValues= new ContentValues();
        contentValues.put(COL_3, bunkinc);
        db.update(TABLE_NAME,contentValues,COLUMN_ID+ "=?",new String[]{String.valueOf(id)});
        db.close();

        return bunkinc;
    }
    public int updatebunkdelete(long id){
        SQLiteDatabase db = this.getWritableDatabase();
        int bunk = getbunk(id);
        int bunkdec= --bunk;
        ContentValues contentValues= new ContentValues();
        contentValues.put(COL_3,bunkdec);
        db.update(TABLE_NAME,contentValues,COLUMN_ID+ "=?",new String[]{String.valueOf(id)});
        db.close();
        return bunkdec;
    }
}

我的活动(条形图)

public  void addData(){
        ArrayList<BarEntry> yVals = new ArrayList<>();
        for (int i=0; i<myhelper.queryYdata().size(); i++){
            yVals.add(new BarEntry((((myhelper.queryYdata().get(i)))),i));
        }
        ArrayList<String> xvals= new ArrayList<>();
    for (int i=0;i<myhelper.queryXdata().size();i++){
        xvals.add(myhelper.queryXdata().get(i));
    }


    MyBarDataset dataSet= new MyBarDataset(yVals,"");
    dataSet.setColors(new int[]{ContextCompat.getColor(mcontext,R.color.green),
    ContextCompat.getColor(mcontext,R.color.yellow),
    ContextCompat.getColor(mcontext,R.color.red)});
    BarData data = new BarData(xvals,dataSet);
    mychart.setData(data);
    //bar custamization
    mychart.animateY(1000);
    mychart.setDrawGridBackground(false);
    mychart.setBackgroundColor(Color.WHITE);
    mychart.getXAxis().setPosition(XAxis.XAxisPosition.BOTTOM);
    mychart.getAxisRight().setEnabled(false);
    mychart.setDescription("");
    mychart.getLegend().setEnabled(false);
    mychart.getXAxis().setDrawGridLines(false);
    mychart.getAxisLeft().setDrawGridLines(false);
    mychart.getAxisLeft().setStartAtZero(true);
    mychart.getAxisLeft().setAxisMinValue(0);


}
public class MyBarDataset extends BarDataSet{

    public MyBarDataset(List<BarEntry> yVals, String label) {
        super(yVals, label);
    }

    @Override
    public int getColor(int index){


        if (getEntryForXIndex(index).getVal()<8){
            return mColors.get(0);
        }
        else if (getEntryForXIndex(index).getVal()<13)
            return mColors.get(1);
        else
            return mColors.get(2);

    }
}

推荐答案

据我了解，您希望基于bunk绘制条形，但基于credits绘制条形.使用自定义条形数据集是正确的方法，只需稍作修改即可.下面的代码获取您正在描述的内容.

As I understand it, you want to plot the bars based on bunk but color them based on credits. Using the custom bar dataset is the right approach, just need to modify it a bit. The code below gets what you're describing.

我所做的更改:

• 无法将名称列表传递给BarData，请改用轴值格式化程序
• 更改了自定义栏数据集，使其也保存了credits数组.不知道您的getEntryForXIndex方法是否在其他地方定义，但是不在您发布的代码中.
• 已删除不赞成使用的调用和无效的语法(无法调用setDescription("");)

• Cannot pass list of names to BarData, use an axis value formatter instead
• Changed custom bar dataset to also hold the credits array. Not sure if your getEntryForXIndex method is defined elsewhere, but it's not in the code you posted.
• Removed deprecated calls and invalid syntax (can't call setDescription("");)

如果这不是您要查找的内容，请更新有关您所看到的内容的更多详细信息，等等.据我所知，问题与图表有关，与SQL数据库无关.

If this isn't what you're looking for, update the question with more detail about what you're seeing etc... As far as I could tell the question was about the chart and not about the SQL database.

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    BarChart chart = findViewById(R.id.test_chart);

    // Some made up data - replace these with your
    //  queryYdata, queryXdata, and queryZdata methods
    String[] names = new String[]{"foo","bar","fiz","bam","boo"};
    List<Float> credits = new ArrayList<>(Arrays.asList(1f,9f,2.5f,15f,50f));
    float[] bunks = new float[]{10f,15f,16f,20f,5f};

    List<BarEntry> entries = new ArrayList<>();
    for(int i = 0; i < bunks.length; ++i) {
        entries.add(new BarEntry(i, bunks[i]));
    }

    float textSize = 16f;

    MyBarDataset dataSet = new MyBarDataset(entries, "data", credits);
    dataSet.setColors(ContextCompat.getColor(this,R.color.green),
            ContextCompat.getColor(this,R.color.yellow),
            ContextCompat.getColor(this,R.color.red));
    BarData data = new BarData(dataSet);
    data.setDrawValues(false);
    data.setBarWidth(0.9f);

    chart.setData(data);
    chart.setFitBars(true);
    chart.getXAxis().setValueFormatter(new IndexAxisValueFormatter(names));
    chart.getXAxis().setPosition(XAxis.XAxisPosition.BOTTOM);
    chart.getXAxis().setTextSize(textSize);
    chart.getAxisLeft().setTextSize(textSize);
    chart.setExtraBottomOffset(10f);

    chart.getAxisRight().setEnabled(false);
    Description desc = new Description();
    desc.setText("");
    chart.setDescription(desc);
    chart.getLegend().setEnabled(false);
    chart.getXAxis().setDrawGridLines(false);
    chart.getAxisLeft().setDrawGridLines(false);

    chart.invalidate();
}

public class MyBarDataset extends BarDataSet{

    private List<Float> credits;

    MyBarDataset(List<BarEntry> yVals, String label, List<Float> credits) {
        super(yVals, label);
        this.credits = credits;
    }

    @Override
    public int getColor(int index){
        float c = credits.get(index);

        if (c < 8){
            return mColors.get(0);
        }
        else if (c < 13) {
            return mColors.get(1);
        }
        else {
            return mColors.get(2);
        }
    }
}

编辑:关于SQL数据库的一句话-不要在循环内调用queryXData和queryYData！这将在每次循环迭代时提取整个数据数组，然后在循环本身中再次提取(非常昂贵).只需使用类似这样的内容即可:

An aside about the SQL database - don't call queryXData and queryYData inside the loop! This will extract the entire data array every loop iteration, then again inside the loop itself (very expensive). Just use something like this instead:

ArrayList<BarEntry> yVals = new ArrayList<>();
ArrayList<Integer> yData = myhelper.queryYdata();
for (int i=0; i<yData.size(); i++){
    yVals.add(new BarEntry(i,yData.get(i)));
}

ArrayList<String> xData = myhelper.queryXdata();

这篇关于如何基于sqlite中存储的某些单个值更改MPandroidCharts中的条形颜色?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！