Question

不在文本视图中键入任何内容我的代码;

公共类MainActivity扩展Activity { 私人按钮按钮;

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



    button=(Button)findViewById(R.id.button);

    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {

            Intent intent = new Intent(MainActivity.this,page.class);
            startActivity(intent);

        }
    });

}

}

public class CustomPagerAdapter extends PagerAdapter {

private Context mContext;

public CustomPagerAdapter(Context context) {
    mContext = context;
}

@Override
public Object instantiateItem(ViewGroup collection, int position) {
    ModelObject modelObject = ModelObject.values()[position];
    LayoutInflater inflater = LayoutInflater.from(mContext);
    ViewGroup layout = (ViewGroup) inflater.inflate(modelObject.getLayoutResId(), collection, false);
    collection.addView(layout);
    return layout;
}

@Override
public void destroyItem(ViewGroup collection, int position, Object view) {
    collection.removeView((View) view);
}

@Override
public int getCount() {
    return ModelObject.values().length;
}

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

@Override
public CharSequence getPageTitle(int position) {
    ModelObject customPagerEnum = ModelObject.values()[position];

    return mContext.getString(customPagerEnum.getTitleResId());
}

}

public enum ModelObject {

WHİTE(R.string.white,R.layout.view_white),
GREEN(R.string.green, R.layout.view_green);

private int mTitleResId;
private int mLayoutResId;

ModelObject(int titleResId, int layoutResId) {
    mTitleResId = titleResId;
    mLayoutResId = layoutResId;
}

public int getTitleResId() {
    return mTitleResId;
}

public int getLayoutResId() {
    return mLayoutResId;
}

}

public class page extends Activity {


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.view_white);

    ViewPager viewPager = (ViewPager) findViewById(R.id.viewpager);
    viewPager.setAdapter(new CustomPagerAdapter(this));




}

}

public class greenPage extends Activity { 私有TextView文本;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.view_green);

    ViewPager viewPager = (ViewPager) findViewById(R.id.viewpager);
    viewPager.setAdapter(new CustomPagerAdapter(this));

    text=(TextView)findViewById(R.id.textView2);

    /*not working ->*/  text.setText("HELLO");

}

}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
          android:layout_width="match_parent"
          android:layout_height="match_parent">

<android.support.v4.view.ViewPager
    android:id="@+id/viewpager"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_alignParentTop="true"
    android:layout_alignParentLeft="true">
    <TextView
        android:id="@+id/textview1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:textAppearance="?android:attr/textAppearanceMedium"
        android:textSize="30sp"
        android:textStyle="normal"
        />



</android.support.v4.view.ViewPager>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
            android:orientation="vertical"
            android:layout_width="match_parent"
            android:background="@android:color/holo_red_dark"
            android:layout_height="match_parent">

<TextView
    android:text="TextView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="193dp"
    android:id="@+id/textView2"/>

请帮帮我。我不是很清楚。请你描述一下吗？

Answer 1

确保您投射TextView的textView2的ID实际上在您的activity.xml

中

尝试使用字符串：

final String HELLO = "HELLO";

TextView text = (TextView)findViewById(R.id.textView2);
text.setText("" + HELLO);

替代方法，如果textView2上当前可用的文本不重要，请将其作为提示，然后在onCreate上更改文本

如果此方法不起作用，请尝试重建项目，这可能是因为您在某处复制了代码，并且项目不知道新添加的值。

我无法在ViewPager中设置文本

1 个答案: