setAdapter(viewPagerAdapter);作用
时间: 2024-01-02 07:04:54 浏览: 68
setAdapter()方法是设置ViewPager的Adapter,将其绑定到ViewPager上,使得ViewPager能够展示Adapter中的数据。在这里,viewPagerAdapter是一个自定义的PagerAdapter,它负责管理ViewPager中的View,包括创建和销毁View以及设置View的内容。调用setAdapter(viewPagerAdapter)可以将viewPagerAdapter与ViewPager关联起来,从而实现数据的展示。
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优化这段代码 private void initPager() { ArrayList<User> list=new ArrayList<>(); ViewPager2 viewPager = findViewById(R.id.view_pager); ArrayList<Fragment> fragments=new ArrayList<>(); User user1=new User(); user1.setSong("等风吹"); user1.setSinger("不是花火呀/小田音乐社"); user1.setImageid(R.drawable.song1); list.add(user1); fragments.add(new ExampleFragment(list)); ViewPagerAdapter pagerAdapter = new ViewPagerAdapter(getSupportFragmentManager(),getLifecycle(),fragments); viewPager.setAdapter(pagerAdapter); }
private void initPager() {
ViewPager2 viewPager = findViewById(R.id.view_pager);
ArrayList<Fragment> fragments = new ArrayList<>();
User user1 = new User();
user1.setSong("等风吹");
user1.setSinger("不是花火呀/小田音乐社");
user1.setImageid(R.drawable.song1);
fragments.add(ExampleFragment.newInstance(user1));
ViewPagerAdapter pagerAdapter = new ViewPagerAdapter(getSupportFragmentManager(), getLifecycle(), fragments);
viewPager.setAdapter(pagerAdapter);
}
// 在 ExampleFragment 中添加 newInstance() 静态方法
public static ExampleFragment newInstance(User user) {
ExampleFragment fragment = new ExampleFragment();
Bundle args = new Bundle();
args.putSerializable("user", user);
fragment.setArguments(args);
return fragment;
}
// 在 ExampleFragment 中获取 User 数据
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mUser = (User) getArguments().getSerializable("user");
}
}
编写Android应用程序代码:请设计一个“掌上驴友”的软件,其中登录界面上密码输入部分要求密码显示。登陆后的中心框架界面用选项卡的形式来设计,“掌上驴友”的功能分为四个模块。
好的,以下是一个简单的Android应用程序代码示例,实现了“掌上驴友”软件的基本功能。请注意,此代码只是示例,您需要根据自己的需求进行修改和扩展。
```java
import android.os.Bundle;
import android.support.design.widget.TabLayout;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
public class MainActivity extends AppCompatActivity {
private TabLayout tabLayout;
private ViewPager viewPager;
private ViewPagerAdapter viewPagerAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tabLayout = (TabLayout) findViewById(R.id.tab_layout);
viewPager = (ViewPager) findViewById(R.id.view_pager);
viewPagerAdapter = new ViewPagerAdapter(getSupportFragmentManager());
// 添加四个模块页面
viewPagerAdapter.addFragment(new Module1Fragment(), "模块1");
viewPagerAdapter.addFragment(new Module2Fragment(), "模块2");
viewPagerAdapter.addFragment(new Module3Fragment(), "模块3");
viewPagerAdapter.addFragment(new Module4Fragment(), "模块4");
viewPager.setAdapter(viewPagerAdapter);
tabLayout.setupWithViewPager(viewPager);
// 在登录界面上密码输入部分要求密码显示
PasswordEditText passwordEditText = (PasswordEditText) findViewById(R.id.password_edit_text);
passwordEditText.setTransformationMethod(new PasswordTransformationMethod());
}
}
```
其中,`Module1Fragment`、`Module2Fragment`、`Module3Fragment`和`Module4Fragment`是四个模块的页面。您需要根据自己的需求编写这些页面的代码。
另外,`PasswordEditText`是一个自定义的带密码显示功能的EditText控件,您需要自己实现这个控件。以下是一个简单的示例代码:
```java
import android.content.Context;
import android.graphics.drawable.Drawable;
import android.support.v4.content.ContextCompat;
import android.text.InputType;
import android.text.method.PasswordTransformationMethod;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.widget.EditText;
public class PasswordEditText extends EditText {
private Drawable showPasswordDrawable;
private Drawable hidePasswordDrawable;
private boolean isPasswordVisible = false;
public PasswordEditText(Context context) {
super(context);
init();
}
public PasswordEditText(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public PasswordEditText(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init();
}
private void init() {
// 获取显示密码和隐藏密码的drawable
showPasswordDrawable = ContextCompat.getDrawable(getContext(), R.drawable.ic_show_password);
hidePasswordDrawable = ContextCompat.getDrawable(getContext(), R.drawable.ic_hide_password);
// 设置显示密码的drawable的点击事件
showPasswordDrawable.setCallback(new Callback() {
@Override
public void invalidateDrawable(Drawable who) {
invalidate();
}
@Override
public void scheduleDrawable(Drawable who, Runnable what, long when) {
scheduleDrawable(who, what, when);
}
@Override
public void unscheduleDrawable(Drawable who, Runnable what) {
unscheduleDrawable(who, what);
}
});
showPasswordDrawable.setBounds(0, 0, showPasswordDrawable.getIntrinsicWidth(), showPasswordDrawable.getIntrinsicHeight());
// 设置隐藏密码的drawable的点击事件
hidePasswordDrawable.setCallback(new Callback() {
@Override
public void invalidateDrawable(Drawable who) {
invalidate();
}
@Override
public void scheduleDrawable(Drawable who, Runnable what, long when) {
scheduleDrawable(who, what, when);
}
@Override
public void unscheduleDrawable(Drawable who, Runnable what) {
unscheduleDrawable(who, what);
}
});
hidePasswordDrawable.setBounds(0, 0, hidePasswordDrawable.getIntrinsicWidth(), hidePasswordDrawable.getIntrinsicHeight());
// 设置EditText的输入类型为密码
setInputType(InputType.TYPE_CLASS_TEXT | InputType.TYPE_TEXT_VARIATION_PASSWORD);
setTransformationMethod(new PasswordTransformationMethod());
// 设置EditText的右侧drawable为显示密码的drawable
setCompoundDrawables(null, null, showPasswordDrawable, null);
// 设置EditText的drawable的点击事件
setOnTouchListener(new OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
if (event.getAction() == MotionEvent.ACTION_UP) {
// 判断是否点击了drawable
if (event.getX() >= getWidth() - getCompoundPaddingRight()) {
// 切换密码可见性
isPasswordVisible = !isPasswordVisible;
if (isPasswordVisible) {
setCompoundDrawables(null, null, hidePasswordDrawable, null);
setInputType(InputType.TYPE_CLASS_TEXT);
} else {
setCompoundDrawables(null, null, showPasswordDrawable, null);
setInputType(InputType.TYPE_CLASS_TEXT | InputType.TYPE_TEXT_VARIATION_PASSWORD);
}
setSelection(length());
}
}
return false;
}
});
}
}
```