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首页 > 软件编程 > Android > Android获取屏幕宽高与获取控件宽高

Android编程获取屏幕宽高与获取控件宽高的方法

作者:chenguang79

这篇文章主要介绍了Android编程获取屏幕宽高与获取控件宽高的方法,实例分析了Android针对屏幕及控件常用属性的相关操作技巧,需要的朋友可以参考下

本文实例讲述了Android编程获取屏幕宽高与获取控件宽高的方法。分享给大家供大家参考,具体如下:

获取屏幕宽高

// 获取屏幕宽高(方法1)
int screenWidth = getWindowManager().getDefaultDisplay().getWidth(); // 屏幕宽(像素,如:480px)
int screenHeight = getWindowManager().getDefaultDisplay().getHeight(); // 屏幕高(像素,如:800p)
Log.e(TAG + " getDefaultDisplay", "screenWidth=" + screenWidth + "; screenHeight=" + screenHeight);
// 获取屏幕密度(方法2)
DisplayMetrics dm = new DisplayMetrics();
dm = getResources().getDisplayMetrics();
float density = dm.density; // 屏幕密度(像素比例:0.75/1.0/1.5/2.0)
int densityDPI = dm.densityDpi; // 屏幕密度(每寸像素:120/160/240/320)
float xdpi = dm.xdpi;
float ydpi = dm.ydpi;
Log.e(TAG + " DisplayMetrics", "xdpi=" + xdpi + "; ydpi=" + ydpi);
Log.e(TAG + " DisplayMetrics", "density=" + density + "; densityDPI=" + densityDPI);
screenWidth = dm.widthPixels; // 屏幕宽(像素,如:480px)
screenHeight = dm.heightPixels; // 屏幕高(像素,如:800px)
Log.e(TAG + " DisplayMetrics(111)", "screenWidth=" + screenWidth + "; screenHeight=" + screenHeight);
// 获取屏幕密度(方法3)
dm = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(dm);
density = dm.density; // 屏幕密度(像素比例:0.75/1.0/1.5/2.0)
densityDPI = dm.densityDpi; // 屏幕密度(每寸像素:120/160/240/320)
xdpi = dm.xdpi;
ydpi = dm.ydpi;
Log.e(TAG + " DisplayMetrics", "xdpi=" + xdpi + "; ydpi=" + ydpi);
Log.e(TAG + " DisplayMetrics", "density=" + density + "; densityDPI=" + densityDPI);
int screenWidthDip = dm.widthPixels; // 屏幕宽(dip,如:320dip)
int screenHeightDip = dm.heightPixels; // 屏幕宽(dip,如:533dip)
Log.e(TAG + " DisplayMetrics(222)", "screenWidthDip=" + screenWidthDip + "; screenHeightDip=" + screenHeightDip);
screenWidth = (int)(dm.widthPixels * density + 0.5f); // 屏幕宽(px,如:480px)
screenHeight = (int)(dm.heightPixels * density + 0.5f); // 屏幕高(px,如:800px)
Log.e(TAG + " DisplayMetrics(222)", "screenWidth=" + screenWidth + "; screenHeight=" + screenHeight);

获取控件的宽高

一般来说,我们在onCreate里面得到的控件的宽高全是0.采用下面的方法,可以得到真实的宽高

方法一:

int w = View.MeasureSpec.makeMeasureSpec(0,View.MeasureSpec.UNSPECIFIED);
int h = View.MeasureSpec.makeMeasureSpec(0,View.MeasureSpec.UNSPECIFIED);
imageView.measure(w, h);
int height =imageView.getMeasuredHeight();
int width =imageView.getMeasuredWidth();
textView.append("\n"+height+","+width);

此方法会加载onMeasure三次

方法二:

ViewTreeObserver vto = imageView.getViewTreeObserver();
vto.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
  public boolean onPreDraw() {
    int height = imageView.getMeasuredHeight();
    int width = imageView.getMeasuredWidth();
    textView.append("\n"+height+","+width);
    return true;
  }
});

此方法会加载onMeasure二次,但是回调函数会回调很多次

方法三:

ViewTreeObserver vto2 = imageView.getViewTreeObserver();
vto2.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
  @Override
  public void onGlobalLayout() {
    imageView.getViewTreeObserver().removeGlobalOnLayoutListener(this);
    textView.append("\n\n"+imageView.getHeight()+","+imageView.getWidth());
  }
});

此方法会加载onMeasure二次,但是回调函数只回调一次

希望本文所述对大家Android程序设计有所帮助。

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