Question

我创建了简单的计算器应用程序，我想在它下面画一个矩形。矩形边的大小必须是为计算输入的第一个数字乘以10.我不知道我是否正确行事，但我试图在LinearLayout中绘制浅蓝色的矩形。单击“立即绘制”按钮后，必须绘制矩形。运行应用程序后，输入数字并单击立即绘制LinearLayout的颜色消失。

这是我的MainActivity：

package com.example.whodatboy.calculator;

import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.drawable.BitmapDrawable;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.TextView;

import org.w3c.dom.Text;

public class MainActivity extends AppCompatActivity {

    TextView result;
    EditText number1, number2;
    Button addN,subtract,divide,multiplyN,clearAll,drawMe;
    LinearLayout rect;

    int result_num,num1,num2;
    float numm1, numm2;

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

        number1 = (EditText) findViewById(R.id.number1);
        number2 = (EditText) findViewById(R.id.number2);
        result = (TextView)findViewById(R.id.result);

        addN = (Button)findViewById(R.id.addN);
        subtract = (Button)findViewById(R.id.subtract);
        divide = (Button)findViewById(R.id.divide);
        multiplyN = (Button)findViewById(R.id.multiplyN);

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

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

        addN.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                num1 = Integer.parseInt(number1.getText().toString());
                num2 = Integer.parseInt(number2.getText().toString());

                result_num = num1 + num2;
                result.setText(String.valueOf(result_num));

            }
        });

        subtract.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                num1 = Integer.parseInt(number1.getText().toString());
                num2 = Integer.parseInt(number2.getText().toString());

                result_num = num1 - num2;
                result.setText(String.valueOf(result_num));

            }
        });

        divide.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                num1 = Integer.parseInt(number1.getText().toString());
                num2 = Integer.parseInt(number2.getText().toString());

                result_num = num1 / num2;
                result.setText(String.valueOf(result_num));

            }
        });

        multiplyN.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                num1 = Integer.parseInt(number1.getText().toString());
                num2 = Integer.parseInt(number2.getText().toString());

                result_num = num1 * num2;
                result.setText(String.valueOf(result_num));

            }
        });

        clearAll.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                number1.setText("");
                number2.setText("");
                result.setText("");
            }
        });


        drawMe.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                numm1 = Float.parseFloat(number1.getText().toString());

                Paint paint = new Paint();
                paint.setColor(Color.parseColor("#F4D03F"));

                Bitmap bg = Bitmap.createBitmap(480,800,Bitmap.Config.ARGB_8888);

                Canvas canvas  = new Canvas(bg);
                canvas.drawRect(num1*10,num1*10,num1*10,num1*10,paint);

                LinearLayout linearDraw = (LinearLayout)findViewById(R.id.rect);
                linearDraw.setBackground(new BitmapDrawable(bg));

            }
        });



    }
}

这是我的XML文件：

<?xml version="1.0" encoding="utf-8"?>
<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"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <EditText
        android:id="@+id/number1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Number 1"
        android:ems="10"
        android:inputType="number" />

    <EditText
        android:id="@+id/number2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        android:layout_marginTop="35dp"
        android:ems="10"
        android:hint="Number 2"
        android:inputType="number" />

    <TextView
        android:id="@+id/result"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentStart="true"
        android:layout_below="@+id/number2"
        android:text="Result"
        android:textSize="25sp" />

    <Button
        android:id="@+id/addN"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignTop="@+id/subtract"
        android:layout_toEndOf="@+id/divide"
        android:text="+" />

    <Button
        android:id="@+id/subtract"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignTop="@+id/multiplyN"
        android:layout_toEndOf="@+id/multiplyN"
        android:text="-" />

    <Button
        android:id="@+id/multiplyN"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        android:layout_marginTop="122dp"
        android:text="*" />

    <Button
        android:id="@+id/divide"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignTop="@+id/subtract"
        android:layout_toEndOf="@+id/subtract"
        android:text="/" />

    <Button
        android:id="@+id/clearAll"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentStart="true"
        android:layout_below="@+id/addN"
        android:text="Clear" />

    <LinearLayout
        android:id="@+id/rect"
        android:layout_width="match_parent"
        android:layout_height="238dp"
        android:layout_alignParentBottom="true"
        android:layout_alignParentStart="true"
        android:layout_marginBottom="9dp"
        android:layout_marginStart="0dp"
        android:background="#89C4F4"
        android:orientation="vertical">

    </LinearLayout>

    <Button
        android:id="@+id/drawMe"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentEnd="true"
        android:layout_below="@+id/clearAll"
        android:layout_marginEnd="0dp"
        android:text="Draw NOW" />

</RelativeLayout>

Answer 1

您可以尝试将height和width设为num1*10

LinearLayout layout(LinearLayout)findViewById(R.id.rect);
layout.getLayoutParams().height=num1*10;
layout.getLayoutParams().width=num1*10;
layout.setBackgroundColor(Color.parseColor("#F4D03F"));

通过获取第一个输入数字的数字在计算器app下方绘制矩形

1 个答案: