java - 我的代码有什么错误...？

Question

我是 Android studio 的新手..正在制作一个 calci 应用程序。

我有一个不同的算法，无论点击什么按钮，数字都会出现在文本框中，但这并没有发生，你能告诉我一个解决方案吗？

java文件:

package bichkondilla.cal;
import android.app.Activity;
import android.content.Context;
import android.content.SharedPreferences;
import android.preference.PreferenceManager; 
import android.support.v7.app.ActionBarActivity; 
import android.os.Bundle;
import android.text.Editable;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import java.lang.*;
import android.view.View.OnClickListener;

public class MainActivity extends Activity implements OnClickListener {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
}
public void onclick(View v) {
    Button button = (Button) findViewById(R.id.button);
    Button button2 = (Button) findViewById(R.id.button2);
    Button button3 = (Button) findViewById(R.id.button3);
    Button button4 = (Button) findViewById(R.id.button4);
    Button button5 = (Button) findViewById(R.id.button5);
    Button button6 = (Button) findViewById(R.id.button6);
    Button button7 = (Button) findViewById(R.id.button7);
    Button button8 = (Button) findViewById(R.id.button8);
    Button button9 = (Button) findViewById(R.id.button9);
    Button button10 = (Button) findViewById(R.id.button10);
    Button button11 = (Button) findViewById(R.id.button11);
    Button button12 = (Button) findViewById(R.id.button12);
    Button button13 = (Button) findViewById(R.id.button13);
    Button button14 = (Button) findViewById(R.id.button14);
    Button button15 = (Button) findViewById(R.id.button15);
    Button button16 = (Button) findViewById(R.id.button16);
    Button button17 = (Button) findViewById(R.id.button17);
    Button button18 = (Button) findViewById(R.id.button18);
    Button button19 = (Button) findViewById(R.id.button19);
    Button button20 = (Button) findViewById(R.id.button20);
    button.setOnClickListener(this);
    button2.setOnClickListener(this);
    button3.setOnClickListener(this);
    button4.setOnClickListener(this);
    button5.setOnClickListener(this);
    button6.setOnClickListener(this);
    button7.setOnClickListener(this);
    button8.setOnClickListener(this);
    button9.setOnClickListener(this);
    button10.setOnClickListener(this);
    button18.setOnClickListener(this);
    button11.setOnClickListener(this);
    button12.setOnClickListener(this);
    button13.setOnClickListener(this);
    button14.setOnClickListener(this);
    button19.setOnClickListener(this);
    button15.setOnClickListener(this);
    button16.setOnClickListener(this);
    button17.setOnClickListener(this);
    button20.setOnClickListener(this);




}
  public String stpu="";
  public void onClick(View v) {
    String st = " ";
    int sum1 = 0;
    TextView down = (TextView) findViewById(R.id.textView2);
    while (v.getId() != R.id.button20) {
        switch (v.getId()) {

            case R.id.button:
                st = st + 1;
                down.setText(st);
                break;

            case R.id.button2:
                st = st + 2;
                down.setText(st);
                break;

            case R.id.button3:
                st = st + 0;
                down.setText(st);
                break;
            case R.id.button4:
                st = st + 3;
                down.setText(st);
                break;
            case R.id.button5:
                st = st + 4
                down.setText(st);
                break;
            case R.id.button6:
                st = st + 5;
                down.setText(st);
                break;
            case R.id.button7:
                st = st + 6;
                down.setText(st);
                break;
            case R.id.button8:
                st = st + 7;
                down.setText(st);
                break;
            case R.id.button9:
                st = st + 8;
                down.setText(st);
                break;
            case R.id.button10:
                st = st + 9;
                down.setText(st);
                break;
            case R.id.button14:
                st = st + ".";
                down.setText(st);
                break;
            case R.id.button15:
                st = st + "+";
                down.setText(st);
                break;
            case R.id.button16:
                st = st + "-";
                down.setText(st);
                break;
            case R.id.button17:
                st = st + "*";
                down.setText(st);
                break;
            case R.id.button18:
                st = st + "/";
                down.setText(st);
                break;
            case R.id.button19:
                st = " ";
                down.setText(st);
                break;


            default:
                break;

        }


    }
}}

xml 文件:

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="1"
    android:id="@+id/button"
    android:layout_alignParentBottom="true"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true"
    android:layout_marginBottom="66dp"
    android:clickable="true" />

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="2"
    android:id="@+id/button2"
    android:layout_alignTop="@+id/button"
    android:layout_toRightOf="@+id/button"
    android:layout_toEndOf="@+id/button"
    android:clickable="true" />

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="0"
    android:id="@+id/button3"
    android:layout_below="@+id/button2"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true"
    android:layout_alignRight="@+id/button2"
    android:layout_alignEnd="@+id/button2"
    android:clickable="true" />

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="3"
    android:id="@+id/button4"
    android:layout_alignTop="@+id/button2"
    android:layout_toRightOf="@+id/button2"
    android:layout_toEndOf="@+id/button2"
    android:clickable="true" />

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="4"
    android:id="@+id/button5"
    android:layout_above="@+id/button"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true"
    android:clickable="true" />

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="5"
    android:id="@+id/button6"
    android:layout_above="@+id/button2"
    android:layout_toLeftOf="@+id/button4"
    android:layout_toStartOf="@+id/button4"
    android:clickable="true" />

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="6"
    android:id="@+id/button7"
    android:layout_alignTop="@+id/button6"
    android:layout_alignLeft="@+id/button4"
    android:layout_alignStart="@+id/button4"
    android:clickable="true" />

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="7"
    android:id="@+id/button8"
    android:layout_above="@+id/button5"
    android:layout_toLeftOf="@+id/button6"
    android:layout_toStartOf="@+id/button6"
    android:clickable="true" />

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="8"
    android:id="@+id/button9"
    android:layout_alignTop="@+id/button8"
    android:layout_toLeftOf="@+id/button7"
    android:layout_toStartOf="@+id/button7"
    android:clickable="true" />

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="9"
    android:id="@+id/button10"
    android:layout_alignTop="@+id/button9"
    android:layout_alignLeft="@+id/button7"
    android:layout_alignStart="@+id/button7"
    android:clickable="true" />

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="."
    android:id="@+id/button14"
    android:layout_above="@+id/button3"
    android:layout_toRightOf="@+id/button4"
    android:layout_toEndOf="@+id/button4"
    android:clickable="true" />

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="+"
    android:id="@+id/button15"
    android:layout_toRightOf="@+id/button7"
    android:layout_toEndOf="@+id/button7"
    android:layout_alignTop="@+id/button10"
    android:layout_alignBottom="@+id/button7"
    android:clickable="true" />

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="-"
    android:id="@+id/button16"
    android:layout_above="@+id/button10"
    android:layout_alignLeft="@+id/button10"
    android:layout_alignStart="@+id/button10"
    android:layout_alignRight="@+id/button15"
    android:layout_alignEnd="@+id/button15"
    android:clickable="true" />

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="*"
    android:id="@+id/button17"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true"
    android:layout_toLeftOf="@+id/button10"
    android:layout_above="@+id/button8"
    android:clickable="true" />

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="/"
    android:id="@+id/button18"
    android:layout_above="@+id/button17"
    android:layout_toLeftOf="@+id/button15"
    android:layout_alignRight="@+id/button15"
    android:layout_alignEnd="@+id/button15"
    android:clickable="true" />

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="clear screen"
    android:id="@+id/button19"
    android:layout_above="@+id/button17"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true"
    android:layout_toLeftOf="@+id/button18"
    android:layout_toStartOf="@+id/button18"
    android:clickable="true" />

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="="
    android:id="@+id/button20"
    android:layout_below="@+id/button4"
    android:layout_alignLeft="@+id/button4"
    android:layout_alignStart="@+id/button4"
    android:layout_alignRight="@+id/button14"
    android:layout_alignEnd="@+id/button14"
    android:clickable="true" />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceLarge"
    android:id="@+id/textView2"
    android:layout_above="@+id/button18"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true"
    android:layout_alignParentRight="true"
    android:layout_alignParentEnd="true"
    android:clickable="true"
    android:layout_alignParentTop="true" />

Answer 1

因为你定义了双函数public void onclick(View v)，所以像这样改变你的代码。

public void init(){
Button button = (Button) findViewById(R.id.button);
Button button2 = (Button) findViewById(R.id.button2);
Button button3 = (Button) findViewById(R.id.button3);
Button button4 = (Button) findViewById(R.id.button4);
Button button5 = (Button) findViewById(R.id.button5);
Button button6 = (Button) findViewById(R.id.button6);
Button button7 = (Button) findViewById(R.id.button7);
Button button8 = (Button) findViewById(R.id.button8);
Button button9 = (Button) findViewById(R.id.button9);
Button button10 = (Button) findViewById(R.id.button10);
Button button11 = (Button) findViewById(R.id.button11);
Button button12 = (Button) findViewById(R.id.button12);
Button button13 = (Button) findViewById(R.id.button13);
Button button14 = (Button) findViewById(R.id.button14);
Button button15 = (Button) findViewById(R.id.button15);
Button button16 = (Button) findViewById(R.id.button16);
Button button17 = (Button) findViewById(R.id.button17);
Button button18 = (Button) findViewById(R.id.button18);
Button button19 = (Button) findViewById(R.id.button19);
Button button20 = (Button) findViewById(R.id.button20);
button.setOnClickListener(this);
button2.setOnClickListener(this);
button3.setOnClickListener(this);
button4.setOnClickListener(this);
button5.setOnClickListener(this);
button6.setOnClickListener(this);
button7.setOnClickListener(this);
button8.setOnClickListener(this);
button9.setOnClickListener(this);
button10.setOnClickListener(this);
button18.setOnClickListener(this);
button11.setOnClickListener(this);
button12.setOnClickListener(this);
button13.setOnClickListener(this);
button14.setOnClickListener(this);
button19.setOnClickListener(this);
button15.setOnClickListener(this);
button16.setOnClickListener(this);
button17.setOnClickListener(this);
button20.setOnClickListener(this);
}

并在onCreate中调用此函数

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