Question

当设备上有软件底部导航按钮（Back，Home，Menu）时，我试图在屏幕（或屏幕上的元素）上添加底部填充。但是，看起来没有100％准确的方法来获得高度。

我尝试过的是：

  var androidApp = Application.android;
  var context = Utility.ad.getApplicationContext();
  var resources = context.getResources();

  var resourceId = resources.getIdentifier("navigation_bar_height", "dimen", "android");
  if (resourceId > 0) {
    console.log(resources.getDimensionPixelSize(resourceId))
  }

但是这似乎总是返回一些值--126（在模拟器和带有可配置的开启/关闭软件按钮的真实设备上，否则都是硬件按钮））。由于SO的许多答案已经证实，这个解决方案不适用于HTC，OnePlus和其他一些设备。

接下来我想尝试的是这个答案 - How to get height and width of navigation bar programmatically。不幸的是，我正在努力将其转化为Nativescript。

答案：

通过将应用程序可用屏幕大小与实际屏幕大小进行比较，我获得了导航栏大小。我认为当应用程序可用的屏幕尺寸小于实际屏幕尺寸时，存在导航栏。然后我计算导航栏的大小。此方法适用于API 14及更高版本。

public static Point getNavigationBarSize(Context context) {
    Point appUsableSize = getAppUsableScreenSize(context);
    Point realScreenSize = getRealScreenSize(context);

    // navigation bar on the right
    if (appUsableSize.x < realScreenSize.x) {
        return new Point(realScreenSize.x - appUsableSize.x, appUsableSize.y);
    }

    // navigation bar at the bottom
    if (appUsableSize.y < realScreenSize.y) {
        return new Point(appUsableSize.x, realScreenSize.y - appUsableSize.y);
    }

    // navigation bar is not present
    return new Point();
}

public static Point getAppUsableScreenSize(Context context) {
    WindowManager windowManager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
    Display display = windowManager.getDefaultDisplay();
    Point size = new Point();
    display.getSize(size);
    return size;
}

public static Point getRealScreenSize(Context context) {
    WindowManager windowManager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
    Display display = windowManager.getDefaultDisplay();
    Point size = new Point();

    if (Build.VERSION.SDK_INT >= 17) {
        display.getRealSize(size);
    } else if (Build.VERSION.SDK_INT >= 14) {
        try {
            size.x = (Integer) Display.class.getMethod("getRawWidth").invoke(display);
            size.y = (Integer) Display.class.getMethod("getRawHeight").invoke(display);
        } catch (IllegalAccessException e) {} catch (InvocationTargetException e) {} catch (NoSuchMethodException e) {}
    }

    return size;
}

我正在使用NS3，Angular 4并且对Java或Nativescript编程没有任何线索：）

关于如何实现此问题以及如何转换代码的任何想法（如果您认为这是最佳选择）？

Answer 1

我在typescript中给出了代码：

var app = require("application");
declare var android:any;

export function getNavigationBarSize() {
    let context = app.android.context;
    let appUsableSize = getAppUsableScreenSize();
    let realScreenSize = getRealScreenSize();

    // navigation bar on the right
    // I dont care about right nav bar, so i return 0
    if (appUsableSize.x < realScreenSize.x) {
        return 0; // new android.graphics.Point(realScreenSize.x - appUsableSize.x, appUsableSize.y);
    }

    // navigation bar at the bottom
    if (appUsableSize.y < realScreenSize.y) {
        return realScreenSize.y - appUsableSize.y; //new android.graphics.Point(appUsableSize.x, realScreenSize.y - appUsableSize.y);
    }

    // navigation bar is not present
    return 0; //new android.graphics.Point();
}

export function getAppUsableScreenSize() {
    let context = app.android.context;
    let windowManager = context.getSystemService(android.content.Context.WINDOW_SERVICE);
    let display = windowManager.getDefaultDisplay();
    let size = new android.graphics.Point();
    display.getSize(size);
    return size;
}

export function getRealScreenSize() {
    let context = app.android.context;
    let windowManager = context.getSystemService(android.content.Context.WINDOW_SERVICE);
    let display = windowManager.getDefaultDisplay();
    let size = new android.graphics.Point();

    if (android.os.Build.VERSION.SDK_INT >= 17) {
        display.getRealSize(size);
    } else if (android.os.Build.VERSION.SDK_INT >= 14) {
        try {
            size.x = android.view.Display.class.getMethod("getRawWidth").invoke(display);
            size.y = android.view.Display.class.getMethod("getRawHeight").invoke(display);
        } catch (e) {
            console.log(e);
            console.log(e.stack);
        }
    }
    return size;
}

然后我常常检查实际的显示高度：

import platform = require("tns-core-modules/platform");

let navHeight = getNavigationBarSize() / platform.screen.mainScreen.scale;
let usableHeight = platform.screen.mainScreen.heightDIPs - navHeight;

Nativescript中的Android底部导航栏大小

1 个答案: