Question

因此，对于我的代码，我要做的是在包含整数的.txt文件中读取，通过parseInt（）将这些整数存储到数组列表中，然后通过GraphView绘制这些点。我已经为我的代码做了一些调试，我注意到没有任何一点被绘图，当我通过标签打印我的数组列表的值来测试我的代码时，它会崩溃我的应用程序。我不确定发生了什么，因为我认为我在这个过程中走在正确的轨道上。这是我的代码如下。 *注意：我使用TextView标签作为测试来确定数据是否实际被读入（在这种情况下它不是）。提前致谢！

MainActivity.java

package com.example.anjanarajagopal.graph;

import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;

import com.jjoe64.graphview.GraphView;
import com.jjoe64.graphview.series.DataPoint;
import com.jjoe64.graphview.series.LineGraphSeries;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;

public class MainActivity extends ActionBarActivity {

    private static final String TAG = MainActivity.class.getName();
    private static final String FILENAME = "data.txt";
    private TextView textview1;
    private TextView textview2;
    private TextView textview3;
    private TextView textview4;
    private TextView textview5;

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

        List<Integer> data = new ArrayList<Integer>();
        try
        {
            InputStream inputStream = openFileInput(FILENAME);
            if(inputStream != null){
                InputStreamReader streamReader = new InputStreamReader(inputStream);
                BufferedReader bufferedReader = new BufferedReader(streamReader);
                String line;
                while((line = bufferedReader.readLine()) != null)
                {
                    int i = Integer.parseInt(line);
                    data.add(i);
                }
            }
            inputStream.close();
        }
        catch(Exception e)
        {
            System.err.format("Exception occurred trying to read '%s'.", FILENAME);
            e.printStackTrace();
            //return null;
        }
        //for(int i = 0; i < data.size(); i++)
        //{
        //    int value = data.get(i);
        //    System.out.print(value + " ");
        //}
        //textview1 = (TextView)findViewById(R.id.textView1);
        //textview2 = (TextView)findViewById(R.id.textView2);
        //textview3 = (TextView)findViewById(R.id.textView3);
        //textview4 = (TextView)findViewById(R.id.textView4);
        //textview5 = (TextView)findViewById(R.id.textView5);
        //textview1.setText(Integer.toString(data.get(0)));
        //textview2.setText(Integer.toString(data.get(1)));
        //textview3.setText(Integer.toString(data.get(2)));
        //textview4.setText(Integer.toString(data.get(3)));
        //textview5.setText(Integer.toString(data.get(4)));

        GraphView graph;
        graph = (GraphView) findViewById(R.id.graph);
        for(int i = 0; i < data.size(); i++) {
            LineGraphSeries<DataPoint> series = new LineGraphSeries<DataPoint>(new DataPoint[]{
                    new DataPoint(i, data.get(i))
            });
            graph.addSeries(series);
        }
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
    }

}

data.txt中 142 149 146 142 152 165 178 188 171 169 179 155 129 117 125 155 204 251 270 265

activity_main.xml中

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">

<TextView android:text="@string/hello_world" android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/textView5"
    android:layout_below="@+id/textView4"
    android:layout_alignLeft="@+id/textView3"
    android:layout_alignStart="@+id/textView3" />
<com.jjoe64.graphview.GraphView
    android:layout_width="match_parent"
    android:layout_height="200dip"
    android:id="@+id/graph"
    android:layout_alignParentTop="true"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true" />

<TextView
    android:text="@string/hello_world"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/textView2"
    android:layout_centerVertical="true"
    android:layout_centerHorizontal="true" />

<TextView
    android:text="@string/hello_world"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/textView3"
    android:layout_below="@+id/textView2"
    android:layout_alignRight="@+id/graph"
    android:layout_alignEnd="@+id/graph" />

<TextView
    android:text="@string/hello_world"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/textView4"
    android:layout_below="@+id/textView3"
    android:layout_alignLeft="@+id/textView2"
    android:layout_alignStart="@+id/textView2" />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Hello world!"
    android:id="@+id/textView1"
    android:layout_below="@+id/textView5"
    android:layout_alignRight="@+id/textView4"
    android:layout_alignEnd="@+id/textView4" />
</RelativeLayout>

Answer 1

在您的特定情况下，您应该将data.txt放在 src / main / assets 文件夹中。然后代替行

InputStream inputStream = openFileInput(FILENAME);

使用以下行

InputStream inputStream = getAssets().open(FILENAME);

Android Java - 读取整数文本文件，在数组中存储整数，并绘制图形

1 个答案: