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
我从LinearLayout切换过来。LayoutParams to RelativeLayout。LayoutParams来最终得到我在创建的自定义圆环视图上想要的结果。
但是你用的不是gravity而是addRule
RelativeLayout。mCircleParams = new RelativeLayout.LayoutParams(circleheight,circleheight);
mCircleParams.addRule(RelativeLayout.CENTER_IN_PARENT);
其他回答
Java
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.MATCH_PARENT);
params.weight = 1.0f;
params.gravity = Gravity.TOP;
button.setLayoutParams(params);
科特林
val params = LinearLayout.LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT,
LinearLayout.LayoutParams.WRAP_CONTENT
).apply {
weight = 1.0f
gravity = Gravity.TOP
}
对于重力值和如何设置重力检查重力。
基本上，你应该根据父类选择LayoutParams。它可以是RelativeLayout, LinearLayout等等…
我使用类似这样的东西:(Xamarin和c#代码)
LinearLayout linLayout= new LinearLayout(this);
linLayout.SetGravity(GravityFlags.Center);
TextView txtView= new TextView(this);
linLayout.AddView(txtView);
SetGravity把我的textView放在布局的中心。 SetGravity layout属性引用布局内容
完美的工作! !以上答案都不适合我。在Xml文件中设置gravity和设置layout_gravity是不同的。检查下面的代码
// here messageLL is the linear layout in the xml file
// Before adding any view just remove all views
messageLL.removeAllViews();
// FrameLayout is the parent for LinearLayout
FrameLayout.LayoutParams params = new
FrameLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
params.gravity = Gravity.CENTER|Gravity.CENTER_VERTICAL;
messageLL.setLayoutParams(params);
messageText.setVisibility(View.GONE);
messageNoText.setVisibility(View.VISIBLE);
messageLL.addView(messageNoText);
也检查这个，在那里你可以找到关于重力和layout_gravity的清楚解释。
修改现有的布局参数并重新设置布局参数
//Get the current layout params and update the Gravity
(iv.layoutParams as FrameLayout.LayoutParams).gravity = Gravity.START
//Set layout params again (this updates the view)
iv.layoutParams = layoutParams
以上大部分答案都是对的，所以写了一个辅助方法，让你可以使用它 直接在你的项目中。
以编程方式设置layout_gravity
// gravity types : Gravity.BOTTOM, Gravity.START etc.
// view : can be any view example : button, textview, linearlayout, image etc.
// for single view
public static void setLayoutGravity(int gravity, View view){
((LinearLayout.LayoutParams) view.getLayoutParams()).gravity = gravity;
}
// for mulitple views
public static void setLayoutGravity(int gravity, View ...view){
for(View item : view)
((LinearLayout.LayoutParams) item.getLayoutParams()).gravity = gravity;
}
