连续改变布局的背景 [英] Change Layout background continuously

问题描述

我正在在我改变了布局背景不断翻转一样的背景，我在执行使用 Activity.runOnUiThread（）函数，因为背景变化的应用程序它是一个用户界面功能以及使用等待2秒钟线程（）。睡眠（），但应用程序只显示我在末尾提到的布局颜色。

 包com.tutorial.flasher;进口android.app.Activity;
进口android.graphics.Color;
进口android.os.Bundle;
//进口android.os.SystemClock;
//进口android.os.SystemClock;
进口android.widget.LinearLayout;
公共类闪光延伸活动{
    / **当第一次创建活动调用。 * /
     的LinearLayout llaLayout;
     日=新主题（ThreadOne）螺纹;
     活动_activity =新活动（）;
@覆盖
公共无效的onCreate（捆绑savedInstanceState）{
    super.onCreate（savedInstanceState）;
    的setContentView（R.layout.main）;
    llaLayout =（的LinearLayout）findViewById（R.id.layo）;    螺纹T1 =新主题（新的Runnable（）{        公共无效的run（）{
            尝试
            {
                视频下载（2000）;
            }
            赶上（例外五）{
                // TODO：处理异常
            }
        }
    }）;    t1.start（）;
    t1.run（）;
    t1.stop（）;
     _activity.runOnUiThread（新的Runnable（）{
        公共无效的run（）{
            llaLayout.setBackgroundColor（Color.parseColor（＃00FF00））;        }
    }）;
    //t1.currentThread（）;
    t1.start（）;
  t1.run（）;
    t1.stop（）;    _activity.runOnUiThread（新的Runnable（）{
        公共无效的run（）{
                                布局//颜色蓝色
            llaLayout.setBackgroundColor（Color.parseColor（＃0000FF））;        }
    }）;
}
 

}

两者用户界面的变化和螺纹凝视将在一个循环中发生（未示出），但仍然在应用程序改变布局颜色只有一次。
谢谢，
希德

解决方案

1. 您不应该新活动，活动由Android系统的创建。


2. 呼叫 Thread.start 将启动线程，没有必要调用 Thread.run 。

Activity.runOnUiThread 也许不是存档最好的方法，尝试处理程序。下面是示例code：

 公共类BroadcastActivity延伸活动{    公共静态最终诠释CHANGE_BGCOLOR = 1;    私人的LinearLayout llaLayout;    私人处理程序处理程序=新的处理程序（）{
        公共无效的handleMessage（android.os.Message MSG）{
            如果（msg.what == 1）{
                串色=（字符串）msg.obj;
                llaLayout.setBackgroundColor（Color.parseColor（彩色））;
                串nextColor =; //接下来背景颜色;
                消息m = obtainMessage（CHANGE_BGCOLOR，nextColor）;
                sendMessageDelayed（M，200）;
            }
        }
    };    @覆盖
    公共无效的onCreate（捆绑savedInstanceState）{
        super.onCreate（savedInstanceState）;
        的setContentView（R.layout.main）;
        llaLayout =（的LinearLayout）findViewById（R.id.layo）;
        串nextColor =; //接下来背景颜色;
        消息m = handler.obtainMessage（CHANGE_BGCOLOR，nextColor）;
        handler.sendMessageDelayed（M，200）;
    }
}
 

I am making an application in which i am changing the the layout background continually like flipping the background, I am implementing the background change using Activity.runOnUiThread() function since it is a UI function and waiting for 2 seconds using Thread().sleep() but the application only shows the layout color I mentioned in the end.

package com.tutorial.flasher;

import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
//import android.os.SystemClock;
//import android.os.SystemClock;
import android.widget.LinearLayout;


public class flasher extends Activity {
    /** Called when the activity is first created. */
     LinearLayout llaLayout;
     Thread th = new Thread("ThreadOne");
     Activity _activity = new Activity();


@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    llaLayout = (LinearLayout)findViewById(R.id.layo);



    Thread t1 = new Thread(new Runnable() {

        public void run() {
            try
            {
                Thread.sleep(2000);
            }
            catch (Exception e) {
                // TODO: handle exception
            }
        }
    });

    t1.start();
    t1.run();
    t1.stop();


     _activity.runOnUiThread(new Runnable(){
        public void run(){
            llaLayout.setBackgroundColor(Color.parseColor("#00FF00"));

        }
    });
    //t1.currentThread();
    t1.start();
  t1.run();
    t1.stop();

    _activity.runOnUiThread(new Runnable(){
        public void run(){
                                //Color BLUE of layout
            llaLayout.setBackgroundColor(Color.parseColor("#0000FF"));

        }
    });


}

}

Both the UI changes and Thread staring would be happening in a loop(which is not shown) but still the application is changing the layout color only once. Thanks, Sid

解决方案

1. You should not new Activity, Activity is created by Android system.
2. Call Thread.start will start the thread, there is no need to call Thread.run.

Activity.runOnUiThread maybe not the best way to archive this, try Handler. Here is sample code:

public class BroadcastActivity extends Activity {

    public static final int CHANGE_BGCOLOR = 1;

    private LinearLayout llaLayout;

    private Handler handler = new Handler() {
        public void handleMessage(android.os.Message msg) {
            if (msg.what == 1) {
                String color = (String) msg.obj;
                llaLayout.setBackgroundColor(Color.parseColor(color));
                String nextColor = ""; // Next background color;
                Message m = obtainMessage(CHANGE_BGCOLOR, nextColor);
                sendMessageDelayed(m, 200);
            }
        }
    };

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        llaLayout = (LinearLayout)findViewById(R.id.layo);
        String nextColor = ""; // Next background color;
        Message m = handler.obtainMessage(CHANGE_BGCOLOR, nextColor);
        handler.sendMessageDelayed(m, 200);
    }
}

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