java - 以编程方式更改布局权重

Question

我正在尝试以编程方式将 View 的布局权重设置为随机数。我认为我有正确的方法，但我无法获得一些技术细节。这是我到目前为止所拥有的:

public class EnterText extends Activity {

    View view = findViewById(R.id.view1);

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_enter_text);

        Random r = new Random();
        int i1 = r.nextInt(5 - 1) + 1;

        //This is to put the weight in a format like "1f"
        String weight = new StringBuilder(String.valueOf(i1)).append("f").toString();

        int height1;
        view.getLayoutParams().height = height1;    

        int width1;
        view.getLayoutParams().height = width1; 

        //Set the weight
        view.setLayoutParams(new LayoutParams(LayoutParams.height1, LayoutParams.width1, weight));

    }

}

我相信这已经接近工作了，但我遇到了一些错误。首先，我收到错误 The method StringBuilder(String) is undefined for the type EnterText，我认为不应该发生这种情况。其次，在 0dip 处，我收到错误 Syntax error on token ".0d", 。预期。有谁知道如何解决这个问题，有谁知道更好的方法来做我想做的事情？

Answer 1

在 setContentView 调用之后添加对 View 的引用

    setContentView(R.layout.activity_enter_text);
    view = findViewById(R.id.view1);

对于StringBuilder(String)对于EnterText类型未定义，使用new关键字来创建一个新的StringBuilder(我认为你不需要这个)

String weight = new StringBuilder(String.valueOf(i1)).append("f").toString();

对于标记“.0d”的语法错误，。预期，只需使用 getLayoutParams().weight 并为其分配一个 float 而不是 int 值，

LinearLayout.LayoutParams lllp = (LinearLayout.LayoutParams) view.getLayoutParams();
lllp.weight = 0.25f
view.setLayoutParams(lllp); // this one may not be needed

应该看起来像:

View view;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_enter_text);
    view = findViewById(R.id.view1);


    //Set the weight using a float n

    LinearLayout.LayoutParams lllp = (LinearLayout.LayoutParams) view.getLayoutParams();
    lllp.weight = 0.25f; // supply a float like this
    int height1 = 200; // you have to supply a value
    int width1 = 300;  // you have to supply a value
    lllp.width = width1;
    lllp.height = height1; 
    view.setLayoutParams(lllp); // this one may not be needed

}