Question

我正在开发一个Android应用程序，在我将textview添加到主要活动布局中之前，它一直工作良好。

正在显示所有图像。但是，与textview无关，而是在显示屏上显示了无关的内容。下面是mainactivity.java中的代码。

import android.content.Intent;
import android.database.sqlite.SQLiteDatabase;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.InputType;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.TextView;
import android.widget.Toast;

import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;

public class MainActivity extends AppCompatActivity {

ImageButton showBalDialog, showExpDialog, showIncomebtn, showExpbtn;
TextView bal_dialog, total_incomes;

public static final String DB_name = "mydb";

DatabaseHelper m_db;

private String amnt, src, exp, rzn;

private String incomes = "sum";

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

    m_db = new DatabaseHelper(this);

    showBalDialog = findViewById(R.id.btnshowBalDialog);
    showExpDialog = findViewById(R.id.btnshowExpDialog);
    showIncomebtn = findViewById(R.id.btnshowIncomes);
    showExpbtn = findViewById(R.id.btnshowExpenses);
    total_incomes = findViewById(R.id.totalincomes);

    incomes = String.valueOf(total_incomes);
    total_incomes.setText(incomes);
 }
}

下面是来自activity_main.xml的代码

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 
 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:screenOrientation="portrait"
android:layout_height="match_parent"
tools:context=".MainActivity">



<ImageButton
    android:id="@+id/btnshowBalDialog"
    android:scaleType="fitXY"
    android:layout_width="150dp"
    android:layout_height="150dp"
    android:layout_marginStart="20dp"
    android:layout_marginTop="40dp"
    android:cropToPadding="false"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    android:background="@drawable/add_inc"> // this is the image(eye)
</ImageButton>

<ImageButton
    android:id="@+id/btnshowExpDialog"
    android:scaleType="fitXY"
    android:layout_width="150dp"
    android:layout_height="150dp"
    android:layout_marginEnd="20dp"
    android:layout_marginTop="40dp"
    android:cropToPadding="false"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    android:background="@drawable/add_exp"> // this is the image(eye)
</ImageButton>

<ImageButton
    android:id="@+id/btnshowIncomes"
    android:scaleType="fitXY"
    android:layout_width="150dp"
    android:layout_height="150dp"
    android:layout_marginStart="20dp"
    android:layout_marginTop="40dp"
    android:cropToPadding="false"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toBottomOf="@id/btnshowBalDialog"
    android:background="@drawable/income_his"> // this is the image(eye)
</ImageButton>

<ImageButton
    android:id="@+id/btnshowExpenses"
    android:scaleType="fitXY"
    android:layout_width="150dp"
    android:layout_height="150dp"
    android:layout_marginEnd="20dp"
    android:layout_marginTop="40dp"
    android:cropToPadding="false"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintTop_toBottomOf="@id/btnshowExpDialog"
    android:background="@drawable/expense_his"> // this is the image(eye)
</ImageButton>

<TextView
    android:id="@+id/totalincomes"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:gravity="center"
    android:layout_marginTop="20dp"
    android:text="TextView"
    app:layout_constraintTop_toBottomOf="@id/btnshowIncomes"
    app:layout_constraintStart_toStartOf="parent">
</TextView>
 </android.support.constraint.ConstraintLayout>

下面是我得到的，而不是应用程序gui上的Textview。

Answer 1

total_incomes 是Textview，您将TextView与xml中存在的R.id.totalincome绑定。

incomes = String.valueOf(total_incomes);
total_incomes.setText(incomes);

您要获取 total_incomes 的字符串值，并将其存储在 incomes 中，并与在 total_incomes 中设置的值相同。简而言之，您要设置textview ID。

Answer 2

您必须这样做：

total_incomes.setText(incomes);

您的收入值已经在字符串中，无需使用String.valueOf()

代替

incomes = String.valueOf(total_incomes);
    total_incomes.setText(incomes);

应用显示一些不相关的文本而不是Textview

2 个答案: