Android webview转PDF的方法示例

compile 'org.droidparts.dexmaker:dexmaker-mockito:1.5'

File file = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM + "/PDFTest.pdf");
File dexCacheFile;
// 获取需要打印的webview适配器
PrintDocumentAdapter printAdapter;
PageRange[] ranges;
ParcelFileDescriptor descriptor;
/**
a* @param webView
*/
private void printPDFFile(WebView webView) {
if (android.os.Build.VERSION.SDK_INT  = android.os.Build.VERSION_CODES.KITKAT) {
/**
* android 5.0之后，出于对动态注入字节码安全性德考虑，已经不允许随意指定字节码的保存路径了，需要放在应用自己的包名文件夹下。
*/
//新的创建DexMaker缓存目录的方式，直接通过context获取路径
dexCacheFile = getDir("dex", 0);
if (!dexCacheFile.exists()) {
dexCacheFile.mkdir();
}
try {
//创建待写入的PDF文件，pdfFilePath为自行指定的PDF文件路径
if (file.exists()) {
file.delete();
}
file.createNewFile();
descriptor = ParcelFileDescriptor.open(file, ParcelFileDescriptor.MODE_READ_WRITE);
// 设置打印参数
PrintAttributes attributes = new PrintAttributes.Builder()
.setMediaSize(PrintAttributes.MediaSize.ISO_A4)
.setResolution(new PrintAttributes.Resolution("id", Context.PRINT_SERVICE, 300, 300))
.setColorMode(PrintAttributes.COLOR_MODE_COLOR)
.setMinMargins(PrintAttributes.Margins.NO_MARGINS)
.build();
//打印所有界面
ranges = new PageRange[]{PageRange.ALL_PAGES};
printAdapter = webView.createPrintDocumentAdapter();
// 开始打印
printAdapter.onStart();
printAdapter.onLayout(attributes, attributes, new CancellationSignal(), getLayoutResultCallback(new InvocationHandler() {
@Override
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
if (method.getName().equals("onLayoutFinished")) {
// 监听到内部调用了onLayoutFinished()方法，即打印成功
onLayoutSuccess();
} else {
// 监听到打印失败或者取消了打印
}
return null;
}
}, dexCacheFile.getAbsoluteFile()), new Bundle());
} catch (IOException e) {
e.printStackTrace();
}
}
}
/**
* @throws IOException
*/
private void onLayoutSuccess() throws IOException {
if (Build.VERSION.SDK_INT  = Build.VERSION_CODES.KITKAT) {
PrintDocumentAdapter.WriteResultCallback callback = getWriteResultCallback(new InvocationHandler() {
@Override
public Object invoke(Object o, Method method, Object[] objects) throws Throwable {
if (method.getName().equals("onWriteFinished")) {
Toast.makeText(MainActivity.this,"Success",Toast.LENGTH_SHORT).show();
// PDF文件写入本地完成，导出成功
Log.e("onLayoutSuccess","onLayoutSuccess");
} else {
Toast.makeText(MainActivity.this,"导出失败",Toast.LENGTH_SHORT).show();
}
return null;
}
}, dexCacheFile.getAbsoluteFile());
//写入文件到本地
printAdapter.onWrite(ranges, descriptor, new CancellationSignal(), callback);
}else {
Toast.makeText(MainActivity.this,"不支持4.4.以下",Toast.LENGTH_SHORT).show();
}
}
@SuppressLint("NewApi")
public static PrintDocumentAdapter.LayoutResultCallback getLayoutResultCallback(InvocationHandler invocationHandler, File dexCacheDir) throws IOException {
return ProxyBuilder.forClass(PrintDocumentAdapter.LayoutResultCallback.class)
.dexCache(dexCacheDir)
.handler(invocationHandler)
.build();
}
@SuppressLint("NewApi")
public static PrintDocumentAdapter.WriteResultCallback getWriteResultCallback(InvocationHandler invocationHandler, File dexCacheDir) throws IOException {
return ProxyBuilder.forClass(PrintDocumentAdapter.WriteResultCallback.class)
.dexCache(dexCacheDir)
.handler(invocationHandler)
.build();
}