以编程方式将按钮宽度设置为父级LinearLayout的50％ [英] Programmatically set button width to 50% of parent LinearLayout

问题描述

我使用LinearLayout创建了一个对话框，在此对话框中，我有一个按钮.我想将其宽度设置为对话框宽度的50％，但是无论我做什么，该按钮仍会填满整个宽度.主要问题似乎是我无法以编程方式设置按钮的重量.我尝试创建第二个水平LinearLayout，以将按钮的权重设置为0.5f(父级的weightSum为1)，但是没有任何改变.如何将按钮设置为宽度的一半?

我查看了所有其他问题，但是大多数问题都使用xml，因此它们不相关，而以编程方式解决该问题的一个问题是使用像素中的硬编码值，这显然是解决该问题的不正确方法.

添加一些代码

LinearLayout linearLayout = new LinearLayout(mContext);
linearLayout.setOrientation(LinearLayout.VERTICAL);
linearLayout.setWeightSum(1);

// I use these params when I call addContentView
LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.MATCH_PARENT);

testButton = new Button(mContext);
testButton.setText("Test");
testButton.setId(1);
testButton.setWidth(0);
testButton.setGravity(Gravity.CENTER);

LinearLayout buttonLayout = new LinearLayout(mContext);
butonLayout.setOrientation(LinearLayout.HORIZONTAL);

LinearLayout.LayoutParams buttonParams = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT, 0.5f);
testButton.setLayoutParams(buttonParams);
buttonLayout.addView(testButton);

linearLayout.addView(buttonLayout);

...

this.addContentView(scrollView, layoutParams);

解决方案

随着我尝试越来越多的选项，代码变得一团糟.我决定从头开始，这段代码最终奏效:

LinearLayout forButton = new LinearLayout(mContext);
forButton.setOrientation(LinearLayout.HORIZONTAL);
LinearLayout.LayoutParams forButtonParams = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);
forButton.setGravity(Gravity.CENTER);

DisplayMetrics dm = new DisplayMetrics();
this.getWindow().getWindowManager().getDefaultDisplay().getMetrics(dm);
int width = dm.widthPixels;

forButton.addView(testButton);
testButton.getLayoutParams().width = width/2;

I created a Dialog using LinearLayout and in this Dialog, I have a Button. I want to set its width to 50% of the Dialog's width, but no matter what I do, the button is still filling the entire width. The main problem seems to be that I cannot set the button's weight programmatically. I tried creating a second horizontal LinearLayout that would hold the button with weight set to 0.5f (the parent has a weightSum of 1), but that did not change anything. How can I set the button to be half the width?

I've looked at all the other questions but most of them were using xml so they were not relevant, and the one that solved it programmatically was using hardcoded values in pixels which is obviously an incorrect solution to the problem.

EDIT: Adding some code

LinearLayout linearLayout = new LinearLayout(mContext);
linearLayout.setOrientation(LinearLayout.VERTICAL);
linearLayout.setWeightSum(1);

// I use these params when I call addContentView
LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.MATCH_PARENT);

testButton = new Button(mContext);
testButton.setText("Test");
testButton.setId(1);
testButton.setWidth(0);
testButton.setGravity(Gravity.CENTER);

LinearLayout buttonLayout = new LinearLayout(mContext);
butonLayout.setOrientation(LinearLayout.HORIZONTAL);

LinearLayout.LayoutParams buttonParams = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT, 0.5f);
testButton.setLayoutParams(buttonParams);
buttonLayout.addView(testButton);

linearLayout.addView(buttonLayout);

...

this.addContentView(scrollView, layoutParams);

解决方案

As I tried more and more options, the code became a mess. I decided to start from scratch and this code worked in the end:

LinearLayout forButton = new LinearLayout(mContext);
forButton.setOrientation(LinearLayout.HORIZONTAL);
LinearLayout.LayoutParams forButtonParams = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);
forButton.setGravity(Gravity.CENTER);

DisplayMetrics dm = new DisplayMetrics();
this.getWindow().getWindowManager().getDefaultDisplay().getMetrics(dm);
int width = dm.widthPixels;

forButton.addView(testButton);
testButton.getLayoutParams().width = width/2;

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