java - 随机按钮Android项目

Question

我想制作一个应用程序，当您单击按钮时，它会转到屏幕上的随机位置。我希望它是一个 ImageButton，当 onClick 时可以转到屏幕上的随机位置。我以前尝试过。但没有成功。这是我已经尝试过的一些代码。 --->

package com.example.e99900004533.candycollector;

import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.graphics.Point;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Display;
import android.view.ViewGroup.MarginLayoutParams;
import android.animation.ObjectAnimator;
import android.widget.RelativeLayout;
import android.widget.EditText;
import android.widget.ImageButton;
import java.util.Random;

public class MainActivity extends ActionBarActivity {

    public EditText collectedTextEdit;
    public ImageButton candyEdit;
    public int collected = 0;
    public int screenWidth = 300;
    public int screenHeight = 300;
    Random random = new Random();
    public boolean running = true;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        collectedTextEdit = (EditText) findViewById(R.id.collectedText);
        candyEdit = (ImageButton) findViewById(R.id.candy);
        collectedTextEdit.setText("Collected: " + collected);

        Display display = getWindowManager().getDefaultDisplay();
        Point size = new Point();
        display.getSize(size);
        screenWidth = size.x;
        screenHeight = size.y;

        addListenerOnButton();
    }

    public void addListenerOnButton() {
        candyEdit.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                collected += 1;
                collectedTextEdit.setText("Collected: " + collected);

                int candyX = random.nextInt(screenWidth - 50);
                int candyY = random.nextInt(screenHeight - 50);
                System.out.println(candyX + " : " + candyY);

                MarginLayoutParams marginParams = new MarginLayoutParams(candyEdit.getLayoutParams());
                marginParams.setMargins(candyX, candyY, 0, 0);
                RelativeLayout.LayoutParams layoutParams = new RelativeLayout.LayoutParams(marginParams);
                candyEdit.setLayoutParams(layoutParams);

                //if (candyX > screenWidth) {
                    //screenWidth -= 50;
                    //layoutParams.setMargins(candyX, candyY, candyX, LayoutParams.WRAP_CONTENT);
                    //candyEdit.setLayoutParams(layoutParams);
                //}
                //if (candyY > screenHeight) {
                    //screenHeight -= 50;
                    //layoutParams.setMargins(candyX, candyY, LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
                    //candyEdit.setLayoutParams(layoutParams);
                //}

                //while (running == true) {
                    //candyY -= 1;
                    //layoutParams.setMargins(candyX, candyY, candyX, candyY);
                    //candyEdit.setLayoutParams(layoutParams);
                //}
            }
        });
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.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.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

Answer 1

我希望您使用 Android Studio，因为它为您提供了一种享受 Android API 的所有优势的美妙方式。

无论如何，在我发布代码之前，您在 java 代码中设置了 onClickListener，虽然这很好，但它可能会使您的代码变得困惑。一个更美观的解决方案是使用 XML 和按钮的 android:onClick。您将在代码中看到这一点。

Java:

package testinc.com.randombutton;

import android.graphics.Point;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.*;
import android.widget.ImageButton;
import android.widget.LinearLayout;
import android.widget.TextView;

import java.util.Random;


public class MainActivity extends ActionBarActivity {

    // Encapsulating the data just to be safe...
    private int collected = 0;
    private int screenWidth = 300;
    private int screenHeight = 300;

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

        Display display = getWindowManager().getDefaultDisplay();
        Point size = new Point();
        display.getSize(size);
        screenWidth = size.x;
        screenHeight = size.y;

        TextView collectedView = (TextView) findViewById(R.id.collectedTV);
        collectedView.setText("Collected: " + collected);

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.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.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    public void toRandomPosition(View view) {
        // Based on our collection candy collection:
        collected += 1;
        TextView collectedView = (TextView) findViewById(R.id.collectedTV);
        collectedView.setText("Collected: " + collected);

        // Based on position of our candy:
        Random random = new Random();
        // Understand nextInt(N) will go from 0 -> N-1, also are you trying to control where it can go?
        float candyX = (float) random.nextInt(screenWidth - 50);
        float candyY = (float) random.nextInt(screenHeight - 50);
// I didn't write it, but you need to check these float values if they   exceed the screen width and the screen length. */
        // Sout to check coordinates
        System.out.println(candyX + " : " + candyY);

        // To change margins:
        ImageButton imgButton = (ImageButton) findViewById(R.id.changePlace);
        imgButton.setX(candyX);
        imgButton.setY(candyY);
    }
}

安卓:注意:我使用线性布局，因为我不喜欢相对的。我想你可以更改它而不会产生任何影响。

<LinearLayout 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">
    <TextView android:id="@+id/collectedTV"
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"/>
    <ImageButton android:id="@+id/changePlace"
                 android:onClick="toRandomPosition"
                 android:contentDescription="It's a button, ha za"
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"/>

</LinearLayout>

关键部分:

android:onClick="toRandomPosition" 连接到方法，public void toRandomPosition(View view)

setX 和 setY 需要 float 来设置位置。不幸的是，随机类似乎在其类中没有 nextFloat(float n) 。我建议暂时将 int 转换为 float 。

看到我现在正在这样做，这里有一个可能的(我没有检查过)解决坐标超出屏幕边界的方法:

while ( candyX >= screenWidth || candyY >= screenHeight) {
  candyX = (float) random.nextInt(screenWidth - 50); 
  candyY = (float) random.nextInt(screenHeight - 50);
}

我检查了位置是否相等，因为屏幕一角的按钮很难找到，并且可能会偏离显示屏。