按钮的setHeight（）和setWidth（）

Question

Button's setHeight() and setWidth() API becomes invalid in some situation described below In the official doc , it says about the set API

Makes the TextView exactly this many pixels tall. You could do the same thing by specifying this number in the LayoutParams. Note that setting this value overrides any other (minimum / maximum) number of lines or height setting.

But in my practice, i found the set API becomes invalid when less than some value. In another word, it seems to take effect when the value being set is bigger than some default value.

Can somebody explain this to me ?

Answer 1

Every View has it's onMeasure Method you can override. As you can see in Source Code of Android, for a View there is a suggested minimum. Hope it helps :)

protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
setMeasuredDimension(getDefaultSize(getSuggestedMinimumWidth(), widthMeasureSpec),
getDefaultSize(getSuggestedMinimumHeight(), heightMeasureSpec));
 }

Here you can see full Source Code of View: http://grepcode.com/file/repository.grepcode.com/java/ext/com.google.android/android/5.0.0_r1/android/view/View.java#View.onMeasure%28int%2Cint%29