我正在尝试两个活动。编辑和查看活动。我想从edit活动中获取输入,并在view活动中显示。在编辑活动中,我具有“确定/提交”按钮,该按钮批准更改并返回到查看活动,在这种情况下,应使用输入的数据更新输入文本字段。如果按下了“取消”按钮,则显然不会进行任何更改,并且用户将被带回到视图活动。
我已经正确完成了大多数实现,但是无法将输入的数据显示在视图活动中。我想念什么?
这是我用于编辑和查看活动的代码。
ViewActivity.java
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
public class ViewActivity extends AppCompatActivity {
public static final String EXTRA_FNAME = "EXTRA_TEXT";
public static final String EXTRA_LNAME = "EXTRA_TEXT";
public static final String EXTRA_EMAIL = "EXTRA_TEXT";
String Fname, Lname, email;
EditText FNInput, LNInput, emailInput;
Button editButton;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_view);
FNInput = (EditText) findViewById(R.id.FNInput);
LNInput = (EditText) findViewById(R.id.LNInput);
emailInput = (EditText) findViewById(R.id.emailInput);
editButton = (Button) findViewById(R.id.okButton);
editButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
openEditActivity();
}
});
Fname = FNInput.getText().toString();
Lname = LNInput.getText().toString();
email = emailInput.getText().toString();
}
public void openEditActivity(){
Intent intent = new Intent(this, EditActivity.class);
intent.putExtra(EXTRA_FNAME, Fname);
intent.putExtra(EXTRA_LNAME, Lname);
intent.putExtra(EXTRA_EMAIL, email);
startActivity(intent);
}
}
EditActivity.java
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
public class EditActivity extends AppCompatActivity {
public static final String EXTRA_FNAME = "EXTRA_TEXT";
public static final String EXTRA_LNAME = "EXTRA_TEXT";
public static final String EXTRA_EMAIL = "EXTRA_TEXT";
String Fname, Lname, email;
EditText FNInput, LNInput, emailInput;
Button okButton, cancelButton;
private static final String TAG = "EditActivity";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_edit);
FNInput = (EditText) findViewById(R.id.FNInput);
LNInput = (EditText) findViewById(R.id.LNInput);
emailInput = (EditText) findViewById(R.id.emailInput);
okButton = (Button) findViewById(R.id.okButton);
cancelButton = (Button) findViewById(R.id.cancelButton);
okButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
updateViewActivity();
}
});
cancelButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
FNInput.setText("");
LNInput.setText("");
emailInput.setText("");
finish();
}
});
}
public void updateViewActivity(){
Fname = FNInput.getText().toString();
Lname = LNInput.getText().toString();
email = emailInput.getText().toString();
FNInput.setText(Fname);
LNInput.setText(Lname);
emailInput.setText(email);
Intent intent = new Intent(this, ViewActivity.class);
intent.putExtra(EXTRA_FNAME, Fname);
intent.putExtra(EXTRA_LNAME, Lname);
intent.putExtra(EXTRA_EMAIL, email);
startActivity(intent);
}
}
activity_view.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".ViewActivity">
<LinearLayout
android:layout_width="270dp"
android:layout_height="374dp"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_marginStart="57dp"
android:layout_marginTop="75dp"
android:orientation="vertical">
<EditText
android:id="@+id/FNInput"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:ems="10"
android:hint="First Name"
android:inputType="textPersonName" />
<EditText
android:id="@+id/LNInput"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:ems="10"
android:hint="Last Name"
android:inputType="textPersonName" />
<EditText
android:id="@+id/emailInput"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:ems="10"
android:hint="[email protected]"
android:inputType="textEmailAddress" />
<Button
android:id="@+id/okButton"
android:layout_width="153dp"
android:layout_height="wrap_content"
android:text="Edit" />
</LinearLayout>
<TextView
android:id="@+id/viewTV"
android:layout_width="134dp"
android:layout_height="33dp"
android:layout_alignParentEnd="true"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginEnd="135dp"
android:layout_marginBottom="18dp"
android:text="View Activity"
tools:layout_editor_absoluteX="15dp"
tools:layout_editor_absoluteY="687dp" />
</RelativeLayout>
activity_edit.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".EditActivity">
<LinearLayout
android:layout_width="270dp"
android:layout_height="374dp"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_marginStart="57dp"
android:layout_marginTop="75dp"
android:orientation="vertical">
<EditText
android:id="@+id/FNInput"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:ems="10"
android:hint="First Name"
android:inputType="textPersonName" />
<EditText
android:id="@+id/LNInput"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:ems="10"
android:hint="Last Name"
android:inputType="textPersonName" />
<EditText
android:id="@+id/emailInput"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:ems="10"
android:hint="[email protected]"
android:inputType="textEmailAddress" />
<TableRow
android:layout_width="match_parent"
android:layout_height="match_parent" >
<Button
android:id="@+id/okButton"
style="@style/Widget.AppCompat.Button.Borderless.Colored"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="OK"
android:textColor="#03A9F4" />
<Button
android:id="@+id/cancelButton"
style="@style/Widget.AppCompat.Button.ButtonBar.AlertDialog"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Cancel"
android:textAlignment="center" />
</TableRow>
</LinearLayout>
<TextView
android:id="@+id/viewTV"
android:layout_width="108dp"
android:layout_height="38dp"
android:layout_alignParentStart="true"
android:layout_alignParentBottom="true"
android:layout_marginStart="169dp"
android:layout_marginBottom="18dp"
android:text="Edit Activity" />
</RelativeLayout>
嗯,我分享从上面的代码中发现的问题:-
您的ViewActivity.java
应该由一些TextView
组成,您打算在其中显示EditActivity.java
中的数据,但该数据不存在。key
发送数据(另一种复制粘贴证明,不知道发生了什么),即-public static final String EXTRA_FNAME = "EXTRA_TEXT"; // use it as EXTRA_FNAME
public static final String EXTRA_LNAME = "EXTRA_TEXT"; // use it as EXTRA_LNAME
public static final String EXTRA_EMAIL = "EXTRA_TEXT"; // use it as EXTRA_EMAIL
当您向视图活动发送数据时,您需要使用getIntent()
来接收所发送的内容,例如:-String s = getIntent().getString("EXTRA_FNAME");
,它将返回先前活动中分配给此key
的值,同时发送到当前活动。
收到期望值后,在下一行中以如下方式填充TextView
:-textView.setText(s); // fetched from getIntent() previously