Question

我是Android开发的新手，我想用TextView中的文件替换TextView中的文件并将其显示在textView1中。我搜索了很多问题，但解决方案对我不起作用。感谢帮助。这是我的代码：

fragment_profile中的文本视图：

<TextView
    android:id="@+id/textView1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:text="@string/nick"
    android:textColor="#FFFFFF" />

这就是活动：

package com.tom411.pyzdit;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import android.app.Activity;
import android.app.Fragment;
import android.content.Intent;
import android.os.Bundle;
import android.os.Environment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

public class ProfileActivity extends Activity {

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

    if (savedInstanceState == null) {
        getFragmentManager().beginTransaction()
                .add(R.id.container, new PlaceholderFragment()).commit();
    }
    TextView tv = (TextView) findViewById(R.id.textView1);
    File dir = Environment.getExternalStorageDirectory();    
    File file = new File(dir,"/PyzdIt/name.txt");   

    if(file.exists())  
    {   
        StringBuilder text = new StringBuilder();  

        try {  
            BufferedReader br = new BufferedReader(new FileReader(file));  
            String line;  

            while ((line = br.readLine()) != null) {  
                text.append(line);  
                text.append('\n');  
            }
            br.read();
            br.close();
        }  
        catch (IOException e) {  
        }  
        tv.setText(text);  
    } 
}   

public void Back(View view) 
{
    Intent intent = new Intent(ProfileActivity.this, MainActivity.class);
    startActivity(intent);
}

public static class PlaceholderFragment extends Fragment {

    public PlaceholderFragment() {
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_profile,
                container, false);
        return rootView;
    }
}

}

Answer 1

我还没有测试过您的代码，但我要检查的第一件事是访问ExternalStorage 。也许您必须在应用清单中添加<uses-permission>条目以允许访问外部存储（android.permission.READ_EXTERNAL_STORAGE）。

Answer 2

使用此代码可以正常工作：

File logFile = new File("sdcard/text.txt");
               if (logFile.exists())
               {
                  try
                  { FileInputStream fIn = new FileInputStream(logFile);
                        BufferedReader myReader = new BufferedReader(
                                new InputStreamReader(fIn));
                        String aDataRow = "";
                        String aBuffer = "";
                        while ((aDataRow = myReader.readLine()) != null) {
                            aBuffer += aDataRow + "\n";}
                        text.setText(aBuffer); 
                        myReader.close(); 
                      logFile.createNewFile();
                  } 
                  catch (IOException e)
                  {
                     // TODO Auto-generated catch block
                     e.printStackTrace();
                  }

               }

并确保使用清单上的权限

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>

如何从SD卡读取文件并显示文本？

2 个答案: