Question

我正在开发一个使用Printing API的应用。我的手机通过OTG线连接到打印机。

    fis = new FileInputStream("/storage/emulated/0/Download/someFile.pdf");

路径提到的文件被正确打印。没问题。但是当我尝试打印.docx文件或.txt文件时，该应用程序无效。

这是整个代码

package com.example.aditya.print3;
import android.content.Context;
import android.os.Build;
import android.os.Bundle;
import android.os.CancellationSignal;
import android.os.ParcelFileDescriptor;
import android.print.PageRange;
import android.print.PrintAttributes;
import android.print.PrintDocumentAdapter;
import android.print.PrintDocumentInfo;
import android.print.PrintManager;
import android.support.annotation.RequiresApi;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;



public class MainActivity extends AppCompatActivity {



@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
}
@RequiresApi(api = Build.VERSION_CODES.KITKAT)
public void clicked(View view){
    PrintManager printManager = (PrintManager) this.getSystemService(Context.PRINT_SERVICE);
    String jobName = this.getString(R.string.app_name) + " Document";
    printManager.print(jobName, pda, null);
}
PrintDocumentAdapter pda = new PrintDocumentAdapter()
{
    @RequiresApi(api = Build.VERSION_CODES.KITKAT)
    @Override
    public void onLayout(PrintAttributes oldAttributes, PrintAttributes newAttributes, CancellationSignal cancellationSignal, LayoutResultCallback callback, Bundle extras)
    {
        if (cancellationSignal.isCanceled())
        {
            callback.onLayoutCancelled();
            return;
        }

        PrintDocumentInfo pdi = new PrintDocumentInfo.Builder("2.pdf").setContentType(PrintDocumentInfo.CONTENT_TYPE_DOCUMENT).build();
        callback.onLayoutFinished(pdi, true);
    }
    @RequiresApi(api = Build.VERSION_CODES.KITKAT)
    @Override
    public void onWrite(PageRange[] pages, ParcelFileDescriptor destination, CancellationSignal cancellationSignal, WriteResultCallback callback)
    {
        String collected = null;
        InputStream fis = null;
        OutputStream fos = null;
        try {
            fis = new FileInputStream("/storage/emulated/0/Download/fileName.docx");
            fos = new FileOutputStream(destination.getFileDescriptor());
            byte[] dataArray = new byte[fis.available()];
            while (fis.read(dataArray)!=-1){
                fos.write(dataArray);
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            try {
                fis.close();
                fos.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }


        callback.onWriteFinished(new PageRange[]{PageRange.ALL_PAGES});
    }
};
}

这是清单文件。

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.aditya.print3">
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:roundIcon="@mipmap/ic_launcher_round"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">
    <activity android:name=".MainActivity">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>

布局文件。

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.aditya.print3.MainActivity"
android:onClick="clicked">

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Hello World!"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintRight_toRightOf="parent"
    app:layout_constraintTop_toTopOf="parent" />

</android.support.constraint.ConstraintLayout>

我现在已经很久没遇到这个问题了。搜索并尝试了很多东西，但没有运气。任何帮助将不胜感激。

感谢。

Answer 1

引用the documentation for onWrite() of PrintDocumentAdapter（强调补充）：

当内容的特定页面应以的形式>写入给定的文件描述符时调用。

Android不支持打印任意文件格式，例如DOCX或TXT。

如何打印.docx文件

1 个答案: