为什么我的云打印不起作用

Question

我只是从我的SD卡上打印PDF文件。但是当我单击打印按钮时什么都没有发生。

main.xml

<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"
tools:context=".MainActivity" >
<Button
    android:id="@+id/button1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerHorizontal="true"
    android:layout_centerVertical="true"
    android:text="Print" />

main.java

public class MainActivity extends AppCompatActivity {
//to declare a button
Button btnPrint;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    btnPrint = (Button)findViewById(R.id.button1);
    //set OnclickListener
    btnPrint.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            //check the network is available or not
            if(isNetworkAvailable() == false){
                Toast.makeText(MainActivity.this, "Network Connection Not Available Please Try Again Later", Toast.LENGTH_LONG).show();
            }else{
                File file = new File(Environment.getExternalStorageDirectory().getPath() + "personal/Brain Stuff.pdf");
                Intent printIntent = new Intent(MainActivity.this,PrintDialogActivity.class);
                printIntent.setDataAndType(Uri.fromFile(file),"application/pdf");
                printIntent.putExtra("Title","Test Print");
            }
        }
    });
}
public boolean isNetworkAvailable(){
    ConnectivityManager cm = (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo networkInfo = cm.getActiveNetworkInfo();
    //if no network is available means network ingo will be null
    //otherwise check if we are connected
    if(networkInfo!=null && networkInfo.isConnected()){
        Log.e("Network Testing","Available");
        return true;
    }
    Log.e("Network Testing","No Network Available");
    return false;
}

}

print_dialog.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<WebView
    android:id="@+id/webview"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" />

清单

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

当我单击按钮时，什么都没有发生，就在那里。而且我还添加了 printDialogactivity 。我犯了什么错误？指导我

Answer 1

您需要使用

开始活动

startActivity(printIntent);