Question

package com.example.paul_2.a5mai;

import android.content.pm.ActivityInfo;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.RelativeLayout;

import java.util.Random;

public class MainActivity extends AppCompatActivity {
int first=0;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
        start();
    }
    void start () {

//root layout
        LinearLayout root = new LinearLayout(this);
        root.setOrientation(LinearLayout.VERTICAL);
        root.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT,LinearLayout.LayoutParams.MATCH_PARENT));
        setContentView(root);

//butonul de start
        Button StartBTN = new Button(this);
        StartBTN.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT,LinearLayout.LayoutParams.WRAP_CONTENT));
        StartBTN.setText("Click Me");
        root.addView(StartBTN);


// contine toate cele 5 layouturi
        final LinearLayout linearContainer=new LinearLayout(this);
        linearContainer.setOrientation(LinearLayout.HORIZONTAL);
        linearContainer.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT,LinearLayout.LayoutParams.MATCH_PARENT));
        root.addView(linearContainer);

//LINIA 1
        final LinearLayout firstRow = new LinearLayout(this);
        firstRow.setOrientation(LinearLayout.VERTICAL);
        firstRow.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT,LinearLayout.LayoutParams.MATCH_PARENT));
        linearContainer.addView(firstRow);

        //dimensiunea imaginii
        final RelativeLayout.LayoutParams params1 = new RelativeLayout.LayoutParams(260,260);
        //params1.leftMargin =10;
        //params1.topMargin = 10;
       final ImageView imgView = new ImageView(MainActivity.this);
       /* final ImageView imgView = new ImageView(this);

        Random rand = new Random();
        int rndInt = rand.nextInt(3) + 1; // n = the number of images, that start at idx 1
        String imgName = "img" + rndInt;
        int id = getResources().getIdentifier(imgName, "drawable", getPackageName());
        imgView.setImageResource(id);
        firstRow.addView(imgView, params1);*/


        /*final ImageView imgView2 = new ImageView(this);

        Random rand2 = new Random();
        int rndInt2 = rand2.nextInt(3) + 1;
        String imgName2 = "img" + rndInt2;
        int id2 = getResources().getIdentifier(imgName2, "drawable", getPackageName());
        imgView2.setImageResource(id2);
        firstRow.addView(imgView2, params1);


        final ImageView imgView3 = new ImageView(this);

        Random rand3 = new Random();
        int rndInt3 = rand3.nextInt(3) + 1;
        String imgName3 = "img" + rndInt3;
        int id3 = getResources().getIdentifier(imgName3, "drawable", getPackageName());
        imgView3.setImageResource(id3);
        firstRow.addView(imgView3, params1);*/


///////////////////////////////////////////////////////////////////////////////////////////////////////////////

        final LinearLayout secondRow = new LinearLayout(this);
        secondRow.setOrientation(LinearLayout.VERTICAL);
        secondRow.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT,LinearLayout.LayoutParams.MATCH_PARENT));
        linearContainer.addView(secondRow);

        ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

        final LinearLayout thirdRow = new LinearLayout(this);
        thirdRow.setOrientation(LinearLayout.VERTICAL);
        thirdRow.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT,LinearLayout.LayoutParams.MATCH_PARENT));
        linearContainer.addView(thirdRow);

        ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

        final LinearLayout fourthRow = new LinearLayout(this);
        fourthRow.setOrientation(LinearLayout.VERTICAL);
        fourthRow.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT,LinearLayout.LayoutParams.MATCH_PARENT));
        linearContainer.addView(fourthRow);

        //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
        final LinearLayout fivethRow = new LinearLayout(this);
        fivethRow.setOrientation(LinearLayout.VERTICAL);
        fivethRow.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT,LinearLayout.LayoutParams.MATCH_PARENT));
        linearContainer.addView(fivethRow);

        StartBTN.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                first=1;


                //ImageView imgView = new ImageView(MainActivity.this);

                Random rand = new Random();
                int rndInt = rand.nextInt(3) + 1; // n = the number of images, that start at idx 1
                String imgName = "img" + rndInt;
                int id = getResources().getIdentifier(imgName, "drawable", getPackageName());
                imgView.setImageResource(id);
                firstRow.addView(imgView, params1);

                ImageView imgView2 = new ImageView(MainActivity.this);

                Random rand2 = new Random();
                int rndInt2 = rand2.nextInt(3) + 1;
                String imgName2 = "img" + rndInt2;
                int id2 = getResources().getIdentifier(imgName2, "drawable", getPackageName());
                imgView2.setImageResource(id2);
                firstRow.addView(imgView2, params1);


                ImageView imgView3 = new ImageView(MainActivity.this);

                Random rand3 = new Random();
                int rndInt3 = rand3.nextInt(3) + 1;
                String imgName3 = "img" + rndInt3;
                int id3 = getResources().getIdentifier(imgName3, "drawable", getPackageName());
                imgView3.setImageResource(id3);
                firstRow.addView(imgView3, params1);



                final Animation animSlide = AnimationUtils.loadAnimation(getApplicationContext(),R.anim.slide);
                firstRow.startAnimation(animSlide);

            }
        });
    }
}

我想通过单击StartBTN随机生成此图像。代码可以工作，但问题是我第一次点击按钮时生成的图像仍然存在，下次我点击按钮时它们不会改变。我每次点击按钮都需要生成。我能做什么？我应该在哪里声明对象？我怎么能这样做？提前谢谢！

  将对象声明移出onsite事件后的
logcat：   05-17 13：49：26.236 8757-8757 / com.example.paul_2.a5mai E / AndroidRuntime：FATAL EXCEPTION：main                                                                           过程：com.example.paul_2.a5mai，PID：8757                                                                           java.lang.IllegalStateException：指定的子级已有父级。您必须先在孩子的父母身上调用removeView（）       在android.view.ViewGroup.addViewInner（ViewGroup.java:4417）
      在android.view.ViewGroup.addView（ViewGroup.java:4258）
      在android.view.ViewGroup.addView（ViewGroup.java:4230）
      在com.example.paul_2.a5mai.MainActivity $ 1.onClick（MainActivity.java:127）
      在android.view.View.performClick（View.java:5637）
      在android.view.View $ PerformClick.run（View.java:22429）
      在android.os.Handler.handleCallback（Handler.java:751）
      在android.os.Handler.dispatchMessage（Handler.java:95）
      在android.os.Looper.loop（Looper.java:154）
      在android.app.ActivityThread.main（ActivityThread.java:6119）
      at java.lang.reflect.Method.invoke（Native Method）
      在com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run（ZygoteInit.java:886）
      在com.android.internal.os.ZygoteInit.main（ZygoteInit.java:776）

Answer 1

你认为你每次都得到相同的号码，但你没有。您要将所有内容添加到第一行，但只能看到第一行顶部显示的图像。在按钮侦听器中创建ImageView的末尾，将ImageView视图添加到第二行和第三行，您将生成包含随机图像的新行：

        StartBTN.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {


            ImageView imgView = new ImageView(MainActivity.this);

            Random rand = new Random();
            int rndInt = rand.nextInt(3) + 1; // n = the number of images, that start at idx 1
            String imgName = "img" + rndInt;
            int id = getResources().getIdentifier(imgName, "drawable", getPackageName());
            imgView.setImageResource(id);
            firstRow.addView(imgView, params1);

            ImageView imgView2 = new ImageView(MainActivity.this);

            Random rand2 = new Random();
            int rndInt2 = rand2.nextInt(3) + 1;
            String imgName2 = "img" + rndInt2;
            int id2 = getResources().getIdentifier(imgName2, "drawable", getPackageName());
            imgView2.setImageResource(id2);
            secondRow.addView(imgView2, params1);


            ImageView imgView3 = new ImageView(MainActivity.this);

            Random rand3 = new Random();
            int rndInt3 = rand3.nextInt(3) + 1;
            String imgName3 = "img" + rndInt3;
            int id3 = getResources().getIdentifier(imgName3, "drawable", getPackageName());
            imgView3.setImageResource(id3);
            thirdRow.addView(imgView3, params1);



            final Animation animSlide = AnimationUtils.loadAnimation(getApplicationContext(),R.anim.slide);
            firstRow.startAnimation(animSlide);
            secondRow.startAnimation(animSlide);
            thirdRow.startAnimation(animSlide);

        }
    });

在添加新视图之前删除视图

即：

 firstRow.removeAllViews();
 firstRow.addView(imgView, params1);

或

 firstRow.removeView(v);
 firstRow.addView(imgView, params1);

或

 firstRow.removeAllViewsInLayout();
 firstRow.addView(imgView, params1);

Answer 2

每次都不要添加ImageView。问题是，第一次添加的图像没有被删除。所以它仍然显示出来。

只需在按钮点击之外执行以下操作。

ImageView imgView = new ImageView(MainActivity.this);
ImageView imgView2 = new ImageView(MainActivity.this);
ImageView imgView3 = new ImageView(MainActivity.this);

现在在您的点击事件中，获取图片视图并更改此类资源

imgView.setImageResource(R.drawable.bike);

不要一次又一次地添加视图。这些陈述只能在您的代码中完成一次

thirdRow.addView(imgView3, params1);

我想在java（android）

2 个答案: