通过按钮来放大缩小图片

小鱼儿 2024-04-01 02:09 51阅读 0赞

![在这里插入图片描述][7fca2fab6e7b45caa6b2ee04d2671872.png]  
![在这里插入图片描述][b2092ced9c4844beb0fcfc0a0e084266.png]  
![在这里插入图片描述][fcbfd19444b543dca57f4a5866038311.png]  
![在这里插入图片描述][c5880a1392fe4bb281bd86c0282ebf81.png]

完整代码

<?xml version="1.0" encoding="utf-8"?>
    <LinearLayout 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:background="@drawable/bj"
        android:orientation="vertical"
        android:padding="10dp"
        tools:context=".MainActivity">
    
    
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center">
    
            <Button
                android:id="@+id/btn_shrink_image"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginRight="10dp"
                android:onClick="doShrinkImage"
                android:text="@string/shrink_image"/>
    
            <Button
                android:id="@+id/btn_enlarge_image"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginRight="10dp"
                android:onClick="doEnlargeImage"
                android:text="@string/enlarge_image"/>
    
            <ImageButton
                android:id="@+id/btn_exit"
                android:layout_width="40dp"
                android:layout_height="40dp"
                android:background="@drawable/anniu"
                android:onClick="doExit"/>
    
        </LinearLayout>
    
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:gravity="center">
            
            <ImageView
                android:id="@+id/iv_mickey"
                android:layout_width="200dp"
                android:layout_height="300dp"
                android:background="@drawable/mickey"/>
    
        </LinearLayout>
    </LinearLayout>

![在这里插入图片描述][2df7b90f0c204cdfb8af74df7fe47a64.png]  
![在这里插入图片描述][8583219b56964cfda8aaab652e024d05.png]

![在这里插入图片描述][d2782fcc852648698c270707e9336c58.png]

![在这里插入图片描述][28db0b957baf42e5918449c92cdbae18.png]  
![在这里插入图片描述][6adcefdc02944d7daf6606df186c3904.png]  
全部代码

package net.lxd.zoom_iamage;
    
    import androidx.appcompat.app.AppCompatActivity;
    
    import android.os.Bundle;
    import android.view.View;
    import android.widget.ImageView;
    import android.widget.LinearLayout;
    import android.widget.Toast;
    
    public class MainActivity extends AppCompatActivity {
    
        private ImageView ivMikey;//米老鼠图像控件
        private double imageWidth;//图像宽度
        private double imageHeight;//图像高度
        private double screenWidth;//手机屏幕宽度
        private double screenHeight;//手机屏幕高度
        private double scale = 0.95;//缩小比列
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            //利用布局资源文件设置用户界面
            setContentView(R.layout.activity_main);
            //通过资源标识符获取控件实例
            ivMikey=findViewById(R.id.iv_mickey);
    
            //获取屏幕尺寸
            screenWidth=getWindowManager().getDefaultDisplay().getWidth();
            screenHeight=getWindowManager().getDefaultDisplay().getHeight();
            //获取图像尺寸
            imageWidth=ivMikey.getLayoutParams().width;
            imageHeight=ivMikey.getLayoutParams().height;
        }
    
        /**
         * 【缩小图片】按钮单击事件处理方法
         *
         * @param view
         */
        public void doShrinkImage(View view){
            //获取图像尺寸
            int newWidth = (int) (imageWidth * scale);
            int newHeight = (int) (imageHeight * scale);
            //按新尺寸设置图像（不能缩小为零，否则不能再放大）
            if (newWidth >50){
                //按新尺寸设置图像
                ivMikey.setLayoutParams(new LinearLayout.LayoutParams(newWidth,newHeight));
                //更新图像尺寸变量
                imageWidth=ivMikey.getLayoutParams().width;
                imageHeight=ivMikey.getLayoutParams().height;
            }else{
                Toast.makeText(this,"温馨提示：图片不能再缩小，要不然看不见咯~",Toast.LENGTH_LONG).show();
            }
        }
    
        /**
         * 【放大图片】按钮单击事件处理方法
         *
         * @param view
         */
        public void doEnlargeImage(View view){
            //获取图像尺寸
            int newWidth = (int) (imageWidth / scale);
            int newHeight = (int) (imageHeight / scale);
            //按新尺寸设置图像（不能再放大，否则就出界了）
            if (newWidth >screenWidth){
                //按新尺寸设置图像
                ivMikey.setLayoutParams(new LinearLayout.LayoutParams(newWidth,newHeight));
                //更新图像尺寸变量
                imageWidth=ivMikey.getLayoutParams().width;
                imageHeight=ivMikey.getLayoutParams().height;
            }else{
                Toast.makeText(this,"温馨提示：图片不能再放大，要不然就出界了~",Toast.LENGTH_LONG).show();
            }
        }
    
        /**
         * 【关闭】按钮单击事件处理方法
         *
         * @param view
         */
        public void doExit(View view){
            finish();//关闭当前窗口
        }
    }

### 看最后效果 ###

![请添加图片描述][f2d78565e8ab43109c4ce937bfd1ecb8.gif]

[7fca2fab6e7b45caa6b2ee04d2671872.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/01/3195f9f3b9ff4d749b69717f5c56f0f6.png
[b2092ced9c4844beb0fcfc0a0e084266.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/01/aa9151f04b46486dbd325ca97ffeda04.png
[fcbfd19444b543dca57f4a5866038311.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/01/6226adffcf13418c82c640c8038e2265.png
[c5880a1392fe4bb281bd86c0282ebf81.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/01/c2ba777f89fa415ea24bd571f9caced8.png
[2df7b90f0c204cdfb8af74df7fe47a64.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/01/69450c662542482db932c745e70a41c4.png
[8583219b56964cfda8aaab652e024d05.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/01/987239fa19fb4f93acfce5b4a24cd685.png
[d2782fcc852648698c270707e9336c58.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/01/a8532133dee74e8b991ab98ecceacaa5.png
[28db0b957baf42e5918449c92cdbae18.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/01/89be93fbcdf5432e8f72728ba3ce229b.png
[6adcefdc02944d7daf6606df186c3904.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/01/f2cc14d922c94d4b8bda6b8608d7cbf8.png
[f2d78565e8ab43109c4ce937bfd1ecb8.gif]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/01/168a8d914eb3417280ae5e0175b5f77a.gif