android - 为什么我的 RelativeLayout 背景在我添加按钮时变成黑色？

Question

我在下面有一些代码创建了一个 RelativeLayout 并向其添加了一个按钮。从 onCreate() 创建时它绘制得很好，在红色背景上显示蓝色按钮。

但是当点击第一个新按钮时创建一个新的 ReltativeLayout 时，新按钮显示在黑色背景上，所以我的 RelativeLayout 不显示。

有趣的是，如果我注释掉添加按钮的行，它就会起作用，所以按钮会以某种方式影响相对布局。

感谢您的帮助。

package com.android.mikeviewtester;

import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.RelativeLayout;

public class ViewTesterActivity extends Activity {

    void createNewView( int bgColor, int btnColor ) {

        // create a new relative layout
        android.widget.RelativeLayout newView = new android.widget.RelativeLayout( this );

        // create a button
        Button btn = new Button( this );

        // set the background color
        btn.setBackgroundColor( btnColor );

        // create a layoutParams struct for adding the button to the relative layout view
        ViewGroup.LayoutParams params = new ViewGroup.LayoutParams( 100, 100 );

        // add the button to the relative layout
        newView.addView( btn, params );

        // set the relative layout background color
        newView.setBackgroundColor( bgColor );

        // set the ontouch listener for the relativeLayout
        newView.setOnTouchListener( (android.view.View.OnTouchListener) mOnTouchListener );

        // create the layout to fill the activity
        RelativeLayout.LayoutParams viewParams = new RelativeLayout.LayoutParams( RelativeLayout.LayoutParams.FILL_PARENT, RelativeLayout.LayoutParams.FILL_PARENT);

        // set the relative layout as the view
        setContentView( newView, viewParams );
    }

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate( savedInstanceState );

        // create and set the initial view
        createNewView( Color.RED, Color.BLUE );
    }

    // ios - (void)buttonWasPressed:(id)whichButton {
    private android.view.View.OnTouchListener mOnTouchListener = new android.view.View.OnTouchListener() {
        public boolean onTouch(View v, MotionEvent event) {

            if ( v != null )
                v.onTouchEvent( event );

            if ( event.getAction() == MotionEvent.ACTION_UP ) {

                // create and set a new view
                createNewView( Color.GREEN, Color.MAGENTA );
            }

            return true;
        }
    };
}

Answer 1

更改您的代码，即在调用 createNewView(Color.GREEN, Color.MAGENTA); 之前添加 v.setVisibility(View.GONE);;