android - 如何设置 android.widget.textview 的可见性选项

Question

FC 对此有问题

private TextView msg, NameOut, DateOut;
msg = (TextView) findViewById(R.id.txtviewOut) ;

线下...(问题出在这里)

msg.setVisibility(View.INVISIBLE);//set visibility to false on create

如何在应用程序启动时将此 TextView (msg) 的可见性设置为 false？

#1 答案编辑后更新

好的，这是所有的代码:

fragment _main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    tools:context=".MainActivity$PlaceholderFragment">

    <EditText
        android:id="@+id/textenter"
        android:layout_height="wrap_content"
        android:layout_width="match_parent"
        android:layout_below="@+id/lbledt1"
        android:layout_alignParentLeft="true" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Enter Name"
        android:id="@+id/lbledt1"
        android:layout_marginTop="26dp"
        android:layout_centerHorizontal="true" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Enter your date of birth (e.g. xx July 19xx)"
        android:id="@+id/textView"
        android:layout_below="@+id/textenter"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="57dp" />

    <EditText
        android:id="@+id/editText"
        android:layout_height="wrap_content"
        android:layout_width="match_parent"
        android:layout_below="@+id/textView"
        android:layout_alignParentLeft="true" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Press this button"
        android:id="@+id/button"
        android:layout_centerVertical="true"
        android:layout_centerHorizontal="true" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceLarge"
        android:text="You have been awesome since"
        android:id="@+id/txtviewOut"
        android:layout_marginTop="86dp"
        android:textIsSelectable="false"
        android:layout_below="@+id/button"
        android:layout_centerHorizontal="true" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceLarge"
        android:id="@+id/txtoutName"
        android:textIsSelectable="false"
        android:layout_alignBottom="@+id/txtviewOut"
        android:layout_centerHorizontal="true"
        android:layout_marginBottom="41dp" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceLarge"
        android:id="@+id/txtOutDate"
        android:layout_marginTop="28dp"
        android:textIsSelectable="false"
        android:layout_below="@+id/txtviewOut"
        android:layout_centerHorizontal="true" />

MainActivity.java:



 package com.example.helloandroidstudio;

    import android.support.v7.app.ActionBarActivity;
    import android.support.v7.app.ActionBar;
    import android.support.v4.app.Fragment;
    import android.os.Bundle;
    import android.view.LayoutInflater;
    import android.view.Menu;
    import android.view.MenuItem;
    import android.view.View;
    import android.view.ViewGroup;
    import android.os.Build;
    import android.widget.Button;
    import android.widget.EditText;
    import android.widget.TextView;

    public class MainActivity extends ActionBarActivity {

        private Button btnClick;
        private EditText Name, Date;
        private TextView msg, NameOut, DateOut;
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.main);
            btnClick = (Button) findViewById(R.id.button) ;
            Name = (EditText) findViewById(R.id.textenter) ;
            Date = (EditText) findViewById(R.id.editText) ;
            msg = (TextView) findViewById(R.id.txtviewOut) ;
            NameOut = (TextView) findViewById(R.id.txtoutName) ;
            DateOut = (TextView) findViewById(R.id.txtOutDate) ;

    //        msg.setVisibility(View.GONE);//set visibility to false on create
            if (savedInstanceState == null) {
                getSupportFragmentManager().beginTransaction()
                        .add(R.id.container, new PlaceholderFragment())
                        .commit();
            }
        }

        public void onClick(View v)
        {
            if (v == btnClick)
            {
                if (Name.equals("") == false && Date.equals("") == false)
                {
                    NameOut = Name;
                    DateOut = Date;
                    msg.setVisibility(View.VISIBLE);
                }
                else
                {
                    msg.setText("Please complete both fields");
                    msg.setVisibility(View.VISIBLE);
                }
            }

        }


        @Override
        public boolean onCreateOptionsMenu(Menu menu) {

            // Inflate the menu; this adds items to the action bar if it is present.
            getMenuInflater().inflate(R.menu.main, menu);
            return true;
        }

        @Override
        public boolean onOptionsItemSelected(MenuItem item) {
            // Handle action bar item clicks here. The action bar will
            // automatically handle clicks on the Home/Up button, so long
            // as you specify a parent activity in AndroidManifest.xml.
            switch (item.getItemId()) {
                case R.id.action_settings:
                    return true;
            }
            return super.onOptionsItemSelected(item);
        }

        /**
         * A placeholder fragment containing a simple view.
         */
        public static class PlaceholderFragment extends Fragment {

            public PlaceholderFragment() {
            }

            @Override
            public View onCreateView(LayoutInflater inflater, ViewGroup container,
                    Bundle savedInstanceState) {
                View rootView = inflater.inflate(R.layout.fragment_main, container, false);
                return rootView;
            }
        }

    }

我用setInvisibility(View.GONE)试过了，还是FC

我检查了 id 值，分配了一个辅助值，我确实对对象进行了类型转换...

请记住，我已经完成了 c#，但这是我的第一个 java/android 应用程序，所以请多多包涵

Answer 1

好吧，我有点怀疑你到底想完成什么，但我会试着澄清一些概念

if you want to hide your view completely then use Visibility.Gone or if you want to hide it but want to keep the place then use Visibility.Invisible

msg.setVisibility(View.INVISIBLE); // for hiding but keeping the place of your view 

msg.setVisibility(View.GONE);// for  hiding it completely , view will not take any place