android - 这些利润从何而来？-6ren

android - 这些利润从何而来？

转载作者：行者123 更新时间：2023-11-30 00:10:15

我正在编写专有的 PrintService，我在接收到由 Android PrintManager 生成的 PDF 文件时遇到了一些问题。我想某些打印属性设置不正确。

这是我用来打印东西的简单代码。这是我的测试应用程序:

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

    webView = new WebView(this);
    webView.setScrollBarStyle(View.SCROLLBARS_INSIDE_OVERLAY);

    // I also set padding to 0 in case....
    webView.setPadding(0, 0, 0, 0);

    // So I tried to set html margin/padding to 0 but it doesn't change the print preview
    String summary = "<html><body style=\"margin: 0; padding: 0; width:100%; height: 100%;\">" +
            "-------------------------------------<br/>" +
            "I'm just printing something!<br/>" +
            "-------------------------------------<br/>" +
            "</body></html>";
    webView.loadData(summary, "text/html; charset=utf-8", "utf-8");

}

public void createWebPrintJob(View view) {

    PrintManager printManager = (PrintManager) this
            .getSystemService(Context.PRINT_SERVICE);

    if (printManager != null) {
        String jobName = getString(R.string.app_name);
        PrintJob job = null;

        PrintDocumentAdapter printAdapter =
                webView.createPrintDocumentAdapter(jobName);

        if ((job = (printManager.print(jobName, printAdapter,
                new PrintAttributes.Builder().build()))) != null) {
            Toast.makeText(this, "Job succesfully created", Toast.LENGTH_SHORT).show();
        }
    }
}

现在在 PrintService 端，下面是我如何初始化打印机功能:

@Override
public void onStartPrinterStateTracking(@NonNull PrinterId printerId) {
    Log.d(TAG, "onStartPrinterStateTracking");
    PrinterInfo printer = findPrinterInfo(printerId);

    if (printer != null) {

    PrintAttributes.MediaSize rollSize = new PrintAttributes.MediaSize("Roll58mm", "Roll58mm", 1892, 5676);
    PrintAttributes.Margins rollMargins = new PrintAttributes.Margins(0, 0, 0, 0);

        PrinterCapabilitiesInfo capabilities = new PrinterCapabilitiesInfo.Builder(printerId)
                .addMediaSize(rollSize, true)
                .setColorModes(PrintAttributes.COLOR_MODE_MONOCHROME, PrintAttributes.COLOR_MODE_MONOCHROME)
                .addResolution(new PrintAttributes.Resolution("200dpi", "paperRoll", 203,203), true)
                .setMinMargins(rollMargins)
                .build();

        printer = new PrinterInfo.Builder(printer)
                            .setCapabilities(capabilities)
                            .build();
        List<PrinterInfo> printers = new Vector<>();
        printers.add(printer);
        addPrinters(printers);
    } else {
        Log.e(TAG, "Unable to find requested printer !");
    }
}

这是打印预览，所以我不明白为什么我的文本周围有边距或填充，而我为所有指定了 0。

为什么我在这里看到边距，因为我为所有指定了 0？

-编辑-我已经根据一些讨论类似问题但没有成功的帖子更新了我的 onCreate 方法!

最佳答案

我通过向 HTML 添加 css 样式解决了这个问题。

<style type="text/css" media="print">
@page
{
    size:  auto;   /* auto is the initial value */
    margin: 0mm;  /* this affects the margin in the printer settings */
}

html
{
    background-color: #FFFFFF;
    margin: 0px;  /* this affects the margin on the html before sending to printer */
}

body
{
    margin: 0mm; /* margin you want for the content */
}
</style>