按下和返回时如何更改按钮的图像？答案

【问题标题】：How to change Image of button when press and Back press?按下和返回时如何更改按钮的图像？
【发布时间】：2017-06-02 06:14:15
【问题描述】：

我正在做直播。我的问题是，当我按下播放按钮时，图像应该变为停止按钮，当我按下停止按钮时，它应该再次变为播放按钮。我很困惑如何做到这一点？这是我的按钮点击监听器..

 btnPublish.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            btnPublish.setImageResource(R.drawable.recordactive);
            SharedPreferences.Editor editor = sp.edit();
            editor.putString("rtmpUrl", rtmpUrl);
            editor.apply();
            mPublisher.startPublish(rtmpUrl);
            mPublisher.startCamera();
        }
    });

当我按下播放按钮时，它会更改为停止图像，但是当我按下停止按钮时，我的应用程序崩溃了。因为我还没有为此编写任何代码。请指导我如何操作。基本上按下那个停止按钮后我想调用这个函数..

   mPublisher.stopPublish();
                mPublisher.stopRecord();

【问题讨论】：

使用布尔变量来管理启动和停止。
你能告诉我任何示例代码吗？？
分享你的完整代码
我看不到变量“sp”的初始化位置？

标签： android android-layout android-studio imagebutton

【解决方案1】：

boolean showing = false;

 btnPublish.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        if(showing){
            mPublisher.stopPublish();
            mPublisher.stopRecord();
            showing = false;
        }
        else
         {
            btnPublish.setImageResource(R.drawable.recordactive);
          SharedPreferences.Editor editor = sp.edit();
           editor.putString("rtmpUrl", rtmpUrl);
        editor.apply();
        mPublisher.startPublish(rtmpUrl);
        mPublisher.startCamera();
        showing = true;
         }
    }
});

【讨论】：

【解决方案2】：

正如 Ronak 所说，您希望跟踪当前状态。您可以使用布尔变量来做到这一点。像这样的

boolean isRecordActive = false;
btnPublish.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        if (isRecordActive) {
            btnPublish.setImageResource(R.drawable.recordinactive);
            // stop streaming
        } else {
            btnPublish.setImageResource(R.drawable.recordactive);
            SharedPreferences.Editor editor = sp.edit();
            editor.putString("rtmpUrl", rtmpUrl);
            editor.apply();
            mPublisher.startPublish(rtmpUrl);
            mPublisher.startCamera();
        }

        isRecordActive != isRecordActive;
    }
});

【讨论】：

是的。 @Abhishek，尝试这样实现。

【解决方案3】：

我做了这样的事情......

        btnPublish.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            //rtmpUrl = efu.getText().toString();
            btnPublish1.setVisibility(View.VISIBLE);
            btnPublish.setVisibility(View.GONE);
            SharedPreferences.Editor editor = sp.edit();
            editor.putString("rtmpUrl", rtmpUrl);
            editor.apply();
            mPublisher.startPublish(rtmpUrl);
            mPublisher.startCamera();
        }
    });



    btnPublish1.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            //rtmpUrl = efu.getText().toString();
            btnPublish.setVisibility(View.VISIBLE);
            btnPublish1.setVisibility(View.GONE);
            mPublisher.stopPublish();
            mPublisher.stopRecord();
        }
    });

【讨论】：

【解决方案4】：

    btnPublish.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            btnPublish.setImageResource(R.drawable.recordactive);
            SharedPreferences.Editor editor = sp.edit();
            editor.putString("rtmpUrl", rtmpUrl);
            editor.apply();
            //Check what is the image embedded on the button. Assuming button is //ImageButton
            Integer integer = (Integer) btnPublish.getTag();
            integer = integer == null ? 0 : integer;
   switch(integer) {
    case R.drawable.recordactive:
     btnPublish.setDrawableResource(R.drawable.recordstop);  //On click of active, //it should change to recordstop first
     btnPublish.setTag(R.drawable.recordstop);
            mPublisher.startPublish(rtmpUrl);
            mPublisher.startCamera();
     break;
    case R.drawable.recordstop:
btnPublish.setDrawableResource(R.drawable.recordactive);  //On click of stop, 
//it should change to recordactive  first
     btnPublish.setTag(R.drawable.recordactive);
mPublisher.stopPublish();
                mPublisher.stopRecord();
    default:
btnPublish.setDrawableResource(R.drawable.recordactive);  //default is record //active
     btnPublish.setTag(R.drawable.recordactive);
     break;
  }

        }
    });

代码是模拟代码。希望有帮助！！！

【讨论】：

【解决方案5】：

您必须设置一个变量来存储按钮的当前状态，然后相应地工作。下面给出一个例子

boolean isPlaying = false;

btnPublish.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if(isPlaying){
              isPlaying = false;
              //what to do when pressing stop button
              //change your button image
              //stop camera and other things...

            }else{
              isPlaying = true;
              //what to do when pressing the play button
              btnPublish.setImageResource(R.drawable.recordactive);
              SharedPreferences.Editor editor = sp.edit();
              editor.putString("rtmpUrl", rtmpUrl);
              editor.apply();
              mPublisher.startPublish(rtmpUrl);
              mPublisher.startCamera();
            }

        }
    });

【讨论】：