安卓第二课

1 吐司制作

public void makeToast(String str, int showTime){
    Toast toast = Toast.makeText(global_context, str, showTime);            
    toast.setGravity(Gravity.CENTER_VERTICAL|Gravity.CENTER_HORIZONTAL , 0, 0);  //设置显示位置
    TextView v = (TextView) toast.getView().findViewById(android.R.id.message);
    v.setTextColor(Color.YELLOW);     //设置字体颜色
    toast.show();   
}

下面来一个高级的吐司

private void midToast(String str, int showTime)
{
    Toast toast = Toast.makeText(mContext, str, showTime);
    toast.setGravity(Gravity.CENTER_HORIZONTAL|Gravity.BOTTOM , 0, 0);  //设置显示位置
    LinearLayout layout = (LinearLayout) toast.getView();
    layout.setBackgroundColor(Color.BLUE);
    ImageView image = new ImageView(this);
    image.setImageResource(R.mipmap.ic_icon_qitao);
    layout.addView(image, 0);
    TextView v = (TextView) toast.getView().findViewById(android.R.id.message);
    v.setTextColor(Color.YELLOW);     //设置字体颜色
    toast.show();
}

完全自定义toast

private void midToast(String str, int showTime)
{
    LayoutInflater inflater = getLayoutInflater();
    View view = inflater.inflate(R.layout.view_toast_custom,
            (ViewGroup) findViewById(R.id.lly_toast));
    ImageView img_logo = (ImageView) view.findViewById(R.id.img_logo);
    TextView tv_msg = (TextView) view.findViewById(R.id.tv_msg);
    tv_msg.setText(str);
    Toast toast = new Toast(mContext);
    toast.setGravity(Gravity.CENTER, 0, 0);
    toast.setDuration(Toast.LENGTH_LONG);
    toast.setView(view);
    toast.show();
}

圆角背景：bg_toast.xml：
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <!-- 设置透明背景色 -->
    <solid android:color="#BADB66" />
    <!-- 设置一个黑色边框 -->
    <stroke
        android:width="1px"
        android:color="#FFFFFF" />
    <!-- 设置四个圆角的半径 -->
    <corners
        android:bottomLeftRadius="50px"
        android:bottomRightRadius="50px"
        android:topLeftRadius="50px"
        android:topRightRadius="50px" />
    <!-- 设置一下边距,让空间大一点 -->
    <padding
        android:bottom="5dp"
        android:left="5dp"
        android:right="5dp"
        android:top="5dp" />
</shape>  

view_toast_custom.xml：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/lly_toast"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/bg_toast"
    android:orientation="horizontal">

    <ImageView
        android:id="@+id/img_logo"
        android:layout_width="24dp"
        android:layout_height="24dp"
        android:layout_marginLeft="10dp"
        android:src="@mipmap/iv_lol_icon1" />

    <TextView
        android:id="@+id/tv_msg"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="10dp"
        android:textSize="20sp" />

</LinearLayout>

2.scrollView

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private Button btn_down;
    private Button btn_up;
    private ScrollView scrollView;
    private TextView txt_show;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        bindViews();
    }


    private void bindViews() {
        btn_down = (Button) findViewById(R.id.btn_down);
        btn_up = (Button) findViewById(R.id.btn_up);
        scrollView = (ScrollView) findViewById(R.id.scrollView);
        txt_show = (TextView) findViewById(R.id.txt_show);
        btn_down.setOnClickListener(this);
        btn_up.setOnClickListener(this);

        StringBuilder sb = new StringBuilder();
        for (int i = 1; i <= 100; i++) {
            sb.append("呵呵 * " + i + "\n");
        }
        txt_show.setText(sb.toString());

    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.btn_down:
                scrollView.fullScroll(ScrollView.FOCUS_DOWN);
                break;
            case R.id.btn_up:
                scrollView.fullScroll(ScrollView.FOCUS_UP);
                break;
        }
    }
}

3 处理事件

public class MainActivity extends Activity {    
    private Button btnshow;    
        
    @Override    
    protected void onCreate(Bundle savedInstanceState) {    
        super.onCreate(savedInstanceState);    
        setContentView(R.layout.activity_main);    
        btnshow = (Button) findViewById(R.id.btnshow);    
        btnshow.setOnClickListener(new OnClickListener() {    
            //重写点击事件的处理方法onClick()    
            @Override    
            public void onClick(View v) {    
                //显示Toast信息    
                Toast.makeText(getApplicationContext(), "你点击了按钮", Toast.LENGTH_SHORT).show();    
            }    
        });    
    }        
} 

在我看来下面这个是野路子

public class MainActivity extends Activity {    
    @Override    
    protected void onCreate(Bundle savedInstanceState) {    
        super.onCreate(savedInstanceState);    
        setContentView(R.layout.activity_main);     
    }    
    //自定义一个方法,传入一个view组件作为参数    
    public void myclick(View source)    
    {    
        Toast.makeText(getApplicationContext(), "按钮被点击了", Toast.LENGTH_SHORT).show();    
    }    
} 

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    
    xmlns:tools="http://schemas.android.com/tools"    
    android:id="@+id/LinearLayout1"    
    android:layout_width="match_parent"    
    android:layout_height="match_parent"    
    android:orientation="vertical" >    
    <Button     
        android:layout_width="wrap_content"    
        android:layout_height="wrap_content"    
        android:text="按钮"    
        android:onClick="myclick"/>    
 </LinearLayout> 

4 Handler

public void onReflash() {
        // TODO Auto-generated method stub\
        Handler handler = new Handler();
        handler.postDelayed(new Runnable() {
            
            @Override
            public void run() {
                setReflashData();
                showList(apk_list);
                listview.reflashComplete();
            }
        }, 2000);
    }

不说了，这不就是js的settimeout

public class MainActivity extends Activity {  
  
    //定义切换的图片的数组id  
    int imgids[] = new int[]{  
        R.drawable.s_1, R.drawable.s_2,R.drawable.s_3,  
        R.drawable.s_4,R.drawable.s_5,R.drawable.s_6,  
        R.drawable.s_7,R.drawable.s_8  
    };  
    int imgstart = 0;  
      
    final Handler myHandler = new Handler()  
    {  
      @Override  
      //重写handleMessage方法,根据msg中what的值判断是否执行后续操作  
      public void handleMessage(Message msg) {  
        if(msg.what == 0x123)  
           {  
            imgchange.setImageResource(imgids[imgstart++ % 8]);  
           }  
        }  
    };  
    
      
    @Override  
    protected void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.activity_main);  
        final ImageView imgchange = (ImageView) findViewById(R.id.imgchange);  
         
        //使用定时器,每隔200毫秒让handler发送一个空信息  
        new Timer().schedule(new TimerTask() {            
            @Override  
            public void run() {  
                myHandler.sendEmptyMessage(0x123);  
                  
            }  
        }, 0,200);  
    }  
  
} 

5 ViewPager

public class MyPagerAdapter extends PagerAdapter {
    private ArrayList<View> viewLists;

    public MyPagerAdapter() {
    }

    public MyPagerAdapter(ArrayList<View> viewLists) {
        super();
        this.viewLists = viewLists;
    }

    @Override
    public int getCount() {
        return viewLists.size();
    }

    @Override
    public boolean isViewFromObject(View view, Object object) {
        return view == object;
    }

    @Override
    public Object instantiateItem(ViewGroup container, int position) {
        container.addView(viewLists.get(position));
        return viewLists.get(position);
    }

    @Override
    public void destroyItem(ViewGroup container, int position, Object object) {
        container.removeView(viewLists.get(position));
    }
}

public class OneActivity extends AppCompatActivity{

    private ViewPager vpager_one;
    private ArrayList<View> aList;
    private MyPagerAdapter mAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_one);
        vpager_one = (ViewPager) findViewById(R.id.vpager_one);

        aList = new ArrayList<View>();
        LayoutInflater li = getLayoutInflater();
        aList.add(li.inflate(R.layout.view_one,null,false));
        aList.add(li.inflate(R.layout.view_two,null,false));
        aList.add(li.inflate(R.layout.view_three,null,false));
        mAdapter = new MyPagerAdapter(aList);
        vpager_one.setAdapter(mAdapter);
    }
}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/LinearLayout1"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="48dp"
        android:background="#FFC3AB"
        android:gravity="center"
        android:text="简单的ViewPager使用"
        android:textSize="18sp"
        android:textColor="#000000"
        android:textStyle="bold" />


    <android.support.v4.view.ViewPager
        android:id="@+id/vpager_one"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center" />
</LinearLayout>