Question

例如，我想在屏幕上添加3个按钮：一个左对齐，一个对齐中心，最后一个右对齐。

如何在代码中设置布局，而不是xml？

Answer 1

只是一个基本的例子：

RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
params.addRule(RelativeLayout.ALIGN_PARENT_LEFT, RelativeLayout.TRUE);
Button button1;
button1.setLayoutParams(params);

params = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
params.addRule(RelativeLayout.RIGHT_OF, button1.getId());
Button button2;
button2.setLayoutParams(params);

如您所见，这就是您必须要做的事情：

创建RelativeLayout.LayoutParams对象。
使用addRule(int)或addRule(int, int)设置规则。第一种方法用于添加不需要值的规则。
将参数设置为视图（在本例中为每个按钮）。

Answer 2

    RelativeLayout layout = new RelativeLayout(this);
    RelativeLayout.LayoutParams labelLayoutParams = new RelativeLayout.LayoutParams(
            LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT);
    layout.setLayoutParams(labelLayoutParams);


   // If you want to add some controls in this Relative Layout
    labelLayoutParams = new RelativeLayout.LayoutParams(
            LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
    labelLayoutParams.addRule(RelativeLayout.CENTER_IN_PARENT);


    ImageView mImage = new ImageView(this);
    mImage.setBackgroundResource(R.drawable.popupnew_bg);        
    layout.addView(mImage,labelLayoutParams);

    setContentView(layout);

Answer 3

像这样......

 RelativeLayout linearLayout = (RelativeLayout) findViewById(R.id.widget43);
                // ListView listView = (ListView) findViewById(R.id.ListView01);

                LayoutInflater inflater = (LayoutInflater) this
                        .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
                // View footer = inflater.inflate(R.layout.footer, null);
                View footer = LayoutInflater.from(this).inflate(R.layout.footer,
                        null);
                final RelativeLayout.LayoutParams layoutParams = new RelativeLayout.LayoutParams(
                        RelativeLayout.LayoutParams.FILL_PARENT,
                        RelativeLayout.LayoutParams.FILL_PARENT);
                layoutParams.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM, 1);
footer.setLayoutParams(layoutParams);

Answer 4

如果您创建它，只需从视图中拉出布局参数。

$((RelativeLayout)findViewById(R.id.imageButton1)).getLayoutParams();

Answer 5

我希望下面的代码会有所帮助。它将创建一个EditText和一个Log In按钮。两者都相对而言。全部在MainActivity.java中完成。

package com.example.atul.allison;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.RelativeLayout;
import android.widget.Button;
import android.graphics.Color;
import android.widget.EditText;
import android.content.res.Resources;
import android.util.TypedValue;     
    public class MainActivity extends AppCompatActivity {

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            //Layout
            RelativeLayout atulsLayout = new RelativeLayout(this);
            atulsLayout.setBackgroundColor(Color.GREEN);

            //Button
            Button redButton = new Button(this);
            redButton.setText("Log In");
            redButton.setBackgroundColor(Color.RED);

            //Username input
            EditText username =  new EditText(this);

            redButton.setId(1);
            username.setId(2);

            RelativeLayout.LayoutParams buttonDetails= new RelativeLayout.LayoutParams(
                    RelativeLayout.LayoutParams.WRAP_CONTENT,
                    RelativeLayout.LayoutParams.WRAP_CONTENT
            );

            RelativeLayout.LayoutParams usernameDetails= new RelativeLayout.LayoutParams(
                    RelativeLayout.LayoutParams.WRAP_CONTENT,
                    RelativeLayout.LayoutParams.WRAP_CONTENT
            );

            //give rules to position widgets
            usernameDetails.addRule(RelativeLayout.ABOVE,redButton.getId());
            usernameDetails.addRule(RelativeLayout.CENTER_HORIZONTAL);
            usernameDetails.setMargins(0,0,0,50);

            buttonDetails.addRule(RelativeLayout.CENTER_HORIZONTAL);
            buttonDetails.addRule(RelativeLayout.CENTER_VERTICAL);

            Resources r = getResources();
            int px = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 200,r.getDisplayMetrics());
            username.setWidth(px);

            //Add widget to layout(button is now a child of layout)
            atulsLayout.addView(redButton,buttonDetails);
            atulsLayout.addView(username,usernameDetails);

            //Set these activities content/display to this view
            setContentView(atulsLayout);
        }
    }

如何在不在xml中的代码中设置RelativeLayout布局参数？

5 个答案: