如果我措辞不好，我道歉，但为了清楚起见，我会尽力解释 . 我正在使用MPAndroidChart绘制折线图，我按照本教程启动并运行https://www.numetriclabz.com/android-line-chart-using-mpandroidchart-tutorial/#Defining_X-axis_labels . 我做了一些调整以满足我的需求等等 .

在按钮单击时，我调用一个方法，使用编辑文本字段的值添加另一个条目，在我按下每个按钮按下的位置，这样代码就像 entries.add(new Entry(editTextValue, numEntries)); 这样做我想要它做我'm looking at the current activity screen, with the previous value remaining, and the next value being added. However, once i leave that activity and return to it, only the last value remains. My understanding is that I need to have a for loop that will iterate over each element in arraylist when I call the drawGraph method that I' m使用，但我没有't had any luck with this. I'试图使用 for(Entry e: entries) 并使用e代替numEntries，但数据类型不兼容 . 任何帮助是极大的赞赏！

编辑：`public class testActivity扩展AppCompatActivity {int counter = 0; public ArrayList entries = new ArrayList <>（）; public static int lifetimeNums; public static int nums = 0; public static int numEntries;

public static String entryLabel = Integer.toString(numEntries);


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



// Graphing method
public void reDrawGraph(){

    LineChart chart = (LineChart) findViewById(R.id.chart);

    XAxis xAxis = chart.getXAxis();
    xAxis.setPosition(XAxis.XAxisPosition.BOTTOM);

    chart.getAxisLeft().setAxisMaxValue(100);
    chart.getXAxis().setAxisMaxValue(100);


    //Creating list of entries


    LineDataSet dataset = new LineDataSet(entries, "# of Calls");

    // creating labels
    ArrayList<String> labels = new ArrayList<String>();
    for (int i = 0; i < 10 + numEntries; i++) {
        labels.add(Integer.toString(i));
    }


    LineData data = new LineData(labels, dataset);

    entries.add(new Entry(testActivity.nums, numEntries));

    chart.animateXY(1000,1000);
    chart.notifyDataSetChanged();
    chart.invalidate();
    chart.setData(data); // set the data and list of lables into chart

}

public void counterClicked(View view){

    try {

        EditText inputText = (EditText) findViewById(R.id.edit_text_val);
        int localNums = Integer.parseInt(inputText.getText().toString());

        if (counter < 3) {
            nums += localNums;
            counter++;
            numEntries++;

            Toast.makeText(this, "Total Entries" + entries.get(0),
                    Toast.LENGTH_SHORT).show();
            reDrawGraph();
            inputText.getText().clear();
        }

        if (counter == 3){
            lifetimeNums++;
            numEntries++;
            Intent intent = new Intent(this, SelectionActivity.class);

            startActivity(intent);
        }

    }catch (Exception e) {


        Toast.makeText(this, "Please enter a value",
                Toast.LENGTH_SHORT).show();
    }`
java android arraylist mpandroidchart