我创建了一些自定义元素,并希望以编程方式将它们放置在右上角(距离上边缘n个像素,距离右边缘m个像素)。因此,我需要获得屏幕宽度和屏幕高度,然后设置位置:
int px = screenWidth - m;
int py = screenHeight - n;
如何在主活动中获取screenWidth和screenHeight?
我创建了一些自定义元素,并希望以编程方式将它们放置在右上角(距离上边缘n个像素,距离右边缘m个像素)。因此,我需要获得屏幕宽度和屏幕高度,然后设置位置:
int px = screenWidth - m;
int py = screenHeight - n;
如何在主活动中获取screenWidth和screenHeight?
当前回答
这不是更好的解决方案吗?DisplayMetrics提供了您所需的一切,并从API 1开始工作。
public void getScreenInfo(){
DisplayMetrics metrics = new DisplayMetrics();
getActivity().getWindowManager().getDefaultDisplay().getMetrics(metrics);
heightPixels = metrics.heightPixels;
widthPixels = metrics.widthPixels;
density = metrics.density;
densityDpi = metrics.densityDpi;
}
您也可以使用getRealMetrics获得实际显示(包括屏幕装饰,如状态栏或软件导航栏),但这仅适用于17+。
我错过了什么吗?
其他回答
我发现这起了作用。
Rect dim = new Rect();
getWindowVisibleDisplayFrame(dim);
这不是OP的答案,因为他希望以真实像素显示尺寸。我想要“设备无关像素”的尺寸,并从这里汇总答案https://stackoverflow.com/a/17880012/253938在这里https://stackoverflow.com/a/6656774/253938我想到了这个:
DisplayMetrics displayMetrics = Resources.getSystem().getDisplayMetrics();
int dpHeight = (int)(displayMetrics.heightPixels / displayMetrics.density + 0.5);
int dpWidth = (int)(displayMetrics.widthPixels / displayMetrics.density + 0.5);
如果您想要以像素为单位的显示尺寸,可以使用getSize:
Display display = getWindowManager().getDefaultDisplay();
Point size = new Point();
display.getSize(size);
int width = size.x;
int height = size.y;
如果您不在“活动”中,则可以通过WINDOW_SERVICE获取默认显示:
WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
Display display = wm.getDefaultDisplay();
如果您在一个片段中,并且想要实现这一点,只需使用Activity.WindowManager(在Xamarin.Android中)或getActivity().getWindowManager()(在java中)。
在引入getSize之前(在API级别13中),您可以使用现在已弃用的getWidth和getHeight方法:
Display display = getWindowManager().getDefaultDisplay();
int width = display.getWidth(); // deprecated
int height = display.getHeight(); // deprecated
然而,对于用例,您正在描述布局中的边距/填充似乎更合适。
另一种方法是:DisplayMetrics
一种结构,描述有关显示器的一般信息,如大小、密度和字体比例。要访问DisplayMetrics成员,请初始化如下对象:
DisplayMetrics metrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(metrics);
我们可以使用widthPixels获取以下信息:
“显示的绝对宽度(以像素为单位)。”
例子:
Log.d("ApplicationTagName", "Display width in px is " + metrics.widthPixels);
API等级30更新
final WindowMetrics metrics = windowManager.getCurrentWindowMetrics();
// Gets all excluding insets
final WindowInsets windowInsets = metrics.getWindowInsets();
Insets insets = windowInsets.getInsetsIgnoringVisibility(WindowInsets.Type.navigationBars()
| WindowInsets.Type.displayCutout());
int insetsWidth = insets.right + insets.left;
int insetsHeight = insets.top + insets.bottom;
// Legacy size that Display#getSize reports
final Rect bounds = metrics.getBounds();
final Size legacySize = new Size(bounds.width() - insetsWidth,
bounds.height() - insetsHeight);
以下是低于/高于API 30代码的Kotlin扩展函数:
fun Activity.getScreenWidth(): Int {
return if (Build.VERSION.SDK_INT < 30) {
val displayMetrics = DisplayMetrics()
windowManager.defaultDisplay.getMetrics(displayMetrics)
displayMetrics.widthPixels
} else {
val metrics = windowManager.currentWindowMetrics
val insets = metrics.windowInsets
.getInsetsIgnoringVisibility(WindowInsets.Type.systemBars())
metrics.bounds.width() - insets.left - insets.right
}
}
fun Activity.getScreenHeight(): Int {
return if (Build.VERSION.SDK_INT < 30) {
val displayMetrics = DisplayMetrics()
windowManager.defaultDisplay.getMetrics(displayMetrics)
displayMetrics.heightPixels
} else {
val metrics = windowManager.currentWindowMetrics
val insets = metrics.windowInsets
.getInsetsIgnoringVisibility(WindowInsets.Type.systemBars())
metrics.bounds.height() - insets.top - insets.bottom
}
}
对应的Java助手方法:
public int getScreenWidth(Activity activity) {
if (Build.VERSION.SDK_INT < 30) {
DisplayMetrics displayMetrics = new DisplayMetrics();
activity.getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
return displayMetrics.widthPixels;
} else {
WindowMetrics metrics = activity.getWindowManager().getCurrentWindowMetrics();
Insets insets = metrics.getWindowInsets()
.getInsetsIgnoringVisibility(WindowInsets.Type.systemBars());
return metrics.getBounds().width() - insets.left - insets.right;
}
}
public int getScreenHeight(Activity activity) {
if (Build.VERSION.SDK_INT < 30) {
DisplayMetrics displayMetrics = new DisplayMetrics();
activity.getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
return displayMetrics.heightPixels;
} else {
WindowMetrics metrics = activity.getWindowManager().getCurrentWindowMetrics();
Insets insets = metrics.getWindowInsets()
.getInsetsIgnoringVisibility(WindowInsets.Type.systemBars());
return metrics.getBounds().height() - insets.bottom - insets.top;
}
}
现在在Api 30级别上,应该这样做
final WindowMetrics metrics = windowManager.getCurrentWindowMetrics();
// Gets all excluding insets
final WindowInsets windowInsets = metrics.getWindowInsets();
Insets insets = windowInsets.getInsetsIgnoreVisibility(WindowInsets.Type.navigationBars()
| WindowInsets.Type.displayCutout());
int insetsWidth = insets.right + insets.left;
int insetsHeight = insets.top + insets.bottom;
// Legacy size that Display#getSize reports
final Rect bounds = metrics.getBounds();
final Size legacySize = new Size(bounds.width() - insetsWidth,
bounds.height() - insetsHeight);