android 点击更换Button背景出现重叠

Button

android：src=" android:src="@drawable/voice"（A）
点击时A一直存在，怎么办，写了search_voice.setBackgroundResource(0);不起作用
voice.xml
voice_press.xml

 public void onClick(View arg0) {
                         search_voice.setBackgroundResource(0);
                        if(flag){
                            Toast.makeText(getApplicationContext(), "语音开启",Toast.LENGTH_SHORT).show();
                            search_voice.setBackgroundResource(R.drawable.vocie_press);
                            flag = false;
                        }
                        else{
                            Toast.makeText(getApplicationContext(), "语音屏蔽",Toast.LENGTH_SHORT).show();
                            search_voice.setBackgroundResource(R.drawable.vocie);
                            flag = true;
                        }

                    }
                });

你默认先别设置背景呢，你这代码没啥问题，或者你用drawlable的xml来设置各种状态下的效果，比如下面的三态效果

 <?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android" >
    <!-- unpressed -->
    <item android:state_pressed="false" android:state_enabled="false" android:color="@color/white">
        <shape>
             <solid android:color="#bfbfbf"/>
             <corners android:radius="5dp"/>
        </shape>
    </item>
    <item android:state_pressed="false" android:state_enabled="true" android:color="@color/white">
        <shape>
             <solid android:color="#23a8f0"/>
             <corners android:radius="5dp"/>
        </shape>
    </item>
    <!-- pressed -->
    <item android:state_pressed="true" android:state_enabled="true" android:color="@color/white">
        <shape>
             <solid android:color="#176b99"/>
             <corners android:radius="5dp"/>
        </shape>
    </item>
</selector>