5.7

public void onClick(View v) {
 switch (v.getId()) {
 case R.id.btn_main_test1://常用简单的
  startActivity(new Intent(this,SimpleComponent.class));
  break;

 @Override
   public void onClick(View v) {
    //得到内容
    String number = et_simple_num.getText().toString().trim();
    //提示
    Toast.makeText(SimpleComponent.this, number, Toast.LENGTH_SHORT).show();
   }
  });
  iv_simple_play = (ImageView) findViewById(R.id.iv_simple_play);
  iv_simple_play.setOnClickListener(new View.OnClickListener() {
   
   @Override
   public void onClick(View v) {
    // TODO Auto-generated method stub
    if (status) {
     //设置背景图片
     iv_simple_play.setBackgroundResource(android.R.drawable.alert_light_frame);
     //设置前景图片
     iv_simple_play.setImageResource(android.R.drawable.ic_media_pause);
     status=false;
    }else{
    //设置背景图片
    iv_simple_play.setBackgroundResource(android.R.drawable.alert_dark_frame);
    //设置前景图片
    iv_simple_play.setImageResource(android.R.drawable.ic_media_play);
    status=true;
    }
   }
  });
  cb_simple_football = (CheckBox) findViewById(R.id.cb_simple_football);
  cb_simple_lan = (CheckBox) findViewById(R.id.cb_simple_lan);
  cb_simple_pingpong = (CheckBox) findViewById(R.id.cb_simple_pingpong);
  
  //设置选中状态改变的监听
  cb_simple_football.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
   
   @Override
   public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
    // TODO Auto-generated method stub
    if (isChecked) {
     Toast.makeText(SimpleComponent.this, "选中了篮球", Toast.LENGTH_SHORT).show();
    }else{
     Toast.makeText(SimpleComponent.this, "取消选中篮球", Toast.LENGTH_SHORT).show();
    }
   }
  });
  rg_simple_sex = (RadioGroup) findViewById(R.id.rg_simple_sex);
  rg_simple_sex.setOnCheckedChangeListener(new OnCheckedChangeListener() {
   
   @Override
   public void onCheckedChanged(RadioGroup group, int checkedId) {
    // checkedId就是选中的radiobutton的id
    //找到选中的radiobutton
    RadioButton radiobutton=(RadioButton) findViewById(checkedId);
   }

//提示
  Toast.makeText(SimpleComponent.this, "lll", 2).show();

常见的异常:
   1. NullPointerException
    原因: 调用对象的方法/属性，但是对象为null
   2. ClassCastException
    原因: 类型转换异常
  3. ActivityNotFoundException:
   原因: 没有在清单文件中注册Activity,或注册不正确
 基本常见异常的一般分析步骤:
  1. 在lagcat中从上向下找，尽量找到Caused by(会显示有那中异常导致的)
  2. 找出异常的类以及行号，双击进入对应的行