我的问题很简单，
如何设置我的按钮layout_gravity编程?
我在互联网上找到了这个，但它只是抛出了一个空指针异常:
Button MyButton = new Button(this);
LinearLayout.LayoutParams lllp=(LinearLayout.LayoutParams)MyButton.getLayoutParams();
lllp.gravity=Gravity.RIGHT;
MyButton.setLayoutParams(lllp);
MyLinearLayout.addView(MyButton);
有解决方案吗?
当前回答
到RelativeLayout，试试这段代码，它为我工作: yourLayoutParams.addRule (RelativeLayout.ALIGN_PARENT_RIGHT);
其他回答
其余的答案都是对的，我想补充更多的解释。layout_gravity是关于如何在父视图中定位视图。
在调用方法parentView.addView() **后，必须设置重力**。我们可以看到代码:
public void setLayoutParams(ViewGroup.LayoutParams params) {
if (params == null) {
throw new NullPointerException("Layout parameters cannot be null");
}
mLayoutParams = params;
resolveLayoutParams();
if (mParent instanceof ViewGroup) {
((ViewGroup) mParent).onSetLayoutParams(this, params);
}
requestLayout();
}
空指针的问题是因为它在getLayoutParams()之前没有调用addView。
注释已经说过“如果这个视图没有附加到父视图组，或者{@link#setLayoutParams(android.view.ViewGroup.LayoutParams)}没有成功调用，这个方法可能会返回null。”当一个View附加到父ViewGroup时，这个方法不能返回null。
FloatingActionButton sendFab = new FloatingActionButton(this);
FrameLayout.LayoutParams layoutParams = new FrameLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
layoutParams.setMargins(32, 32, 32, 32);
layoutParams.gravity = Gravity.END|Gravity.BOTTOM;
sendFab.setLayoutParams(layoutParams);
sendFab.setImageResource(android.R.drawable.ic_menu_send);
layoutParams2.gravity = Gravity.RIGHT|Gravity.BOTTOM;
用它来增加一个以上的重力
KOTLIN在FrameLayout上设置多个重力而不改变大小:
// assign more than one gravity,Using the operator "or"
var gravity = Gravity.RIGHT or Gravity.CENTER_VERTICAL
// update gravity
(pagerContainer.layoutParams as FrameLayout.LayoutParams).gravity = gravity
// refresh layout
pagerContainer.requestLayout()
int width=getResources().getDisplayMetrics().widthPixels;
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams
(width, width);
params.gravity = Gravity.CENTER;
iv_main_text = new HTextView(getContext());
iv_main_text.setLayoutParams(params);
iv_main_text.setBackgroundColor(Color.BLUE);
iv_main_text.setTextSize(60);
iv_main_text.setGravity(Gravity.CENTER);
iv_main_text.setTextColor(Color.BLACK);
