android getWidth()和getMeasuredWidth()方法的区别

getWidth()

Return the width of the your view.

Returns

  • The width of your view, in pixels.

源代码:

public final int getWidth() {  
        return mRight - mLeft;  
    }

getwidth返回的是右边坐标减轻坐标减去左边坐标,这要在布局之后才能确定它们的坐标,也就是说在布局后才能调用getwidth来获取。所以getWidth()获得的宽度是View在设定好布局后整个View的宽度。

getMeasuredWidth()

Return the full width measurement information for this view as computed by the most recent call to measure(int, int). This result is a bit mask as defined byMEASURED_SIZE_MASK and MEASURED_STATE_TOO_SMALL. This should be used during measurement and layout calculations only. Use getWidth() to see how wide a view is after layout.

Returns

The measured width of this view as a bit mask.

得到的是最近一次调用measure()方法测量后得到的是View的宽度,它应该仅仅用在测量和Layout的计算中。再看源码:

public final int getMeasuredWidth() {  
    return mMeasuredWidth & MEASURED_SIZE_MASK;  
}  

return The raw measured width of this view 获得的是原始的测量宽度。所以说getMeasuredWidth()是对View上的内容进行测量后得到的View内容占据的宽度。前提是你必须在父布局的onLayout()方法或者此View的onDraw()方法里调用measure(0,0);(measure中的参数的值你自己可以定义),否则你得到的结果和getWidth()得到的结果是一样的。

区别

getMeasuredWidth:对View上的内容进行测量后得到的View内容占据的宽度的。

getWidth:View在设定号布局后整个View的宽度。

使用场合

getMeasuredWidth:在自定义view重写onLayout时、在我们用layoutinflater动态加载view后想获得view的原始宽度时。

getWidth:一般在view已经布局后呈现出来了,想获取宽度时。


 
Android <wbr>一张图理解getWidth和getMeasuredWidth
view.getMeasuredHeight()可能隐藏在上头.可能在下头.如果view没有超出屏幕的时候view.getMeasuredHeight() 有可能小于 view.getHeight()
 
 getWidth(): View在設定好佈局後整個View的寬度。
  getMeasuredWidth(): 對View上的內容進行測量後得到的View內容佔據的寬度
原文地址:https://www.cnblogs.com/zquan/p/9623912.html