以編程方式更改布局權重

Question

我試圖以編程方式將 view的布局權重設置為隨機數 。 我認為我有正確的方法，但是我無法獲得一些技術細節。 這是我到目前為止的內容：

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));

    }

}

我相信這接近工作，但是我遇到了一些錯誤。 首先，我收到錯誤消息The method StringBuilder(String) is undefined for the type EnterText ， The method StringBuilder(String) is undefined for the type EnterText ，我認為這不應該發生。 其次，在0dip ，我收到Syntax error on token ".0d", . expected的錯誤Syntax error on token ".0d", . expected Syntax error on token ".0d", . expected 。 有人知道如何解決這個問題，有人知道做我想做的更好的方法嗎？

Answer 1

在setContentView調用之后，將引用添加到那里的視圖

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

對於StringBuilder(String) is undefined for the type EnterText ，請使用new關鍵字創建一個新的StringBuilder（我認為您不需要此方法）

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

對於Syntax error on token ".0d", . expected Syntax error on token ".0d", . expected ，只需使用getLayoutParams（）。weight並為其分配浮點數而不是int值，

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

應該看起來像：

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

}