安卓开发图片动态操作，利用SeekBar控制属性示例

屏幕大小适配演示，综合练习。

功能为，用一个滑块来控制图片的旋转，用一个滑块来控制图片大小，核心语法思路，控制图片的大小，

mImageView.setLayoutParams(new LinearLayout.LayoutParams(newWidth,newHeight));

但是这儿二个属性要提前配置，并且图片大不能超出屏幕，所以先计算屏幕大小，

private void setMaxValueForSeekBar1(){
       DisplayMetrics dmDisplayMetrics = new DisplayMetrics();
       getWindowManager().getDefaultDisplay().getMetrics(dmDisplayMetrics);
       mSeekBar1.setMax(dmDisplayMetrics.widthPixels - MIN_WIDTH);
   }
//这儿先配置滑块的最大数值
图片旋转的配置核心代码为：

Bitmap bitmap = ((BitmapDrawable)getResources().getDrawable(R.drawable.test1)).getBitmap();
Matrix matrix = new Matrix();
matrix.setRotate(i);
bitmap = Bitmap.createBitmap(bitmap,0,0,bitmap.getWidth(), bitmap.getHeight(),matrix,true);
mImageView.setImageBitmap(bitmap);

　完整代码如下：

第一配置　values 文件  string.xml文件如下

<resources>
    <string name="app_name">My Application1</string>
    <string name="image_width">图像宽度</string>
    <string name="image_height">图像高度</string>
    <string name="image_rotate">旋转度数</string>
    <string name="init_rotate">初始角度</string>
</resources>

第二静态布局文件如下

<?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:orientation="vertical"
    tools:context=".MainActivity">

    <ImageView
        android:id="@+id/img"
        android:layout_marginTop="20dp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:scaleType="fitCenter"
        android:src="@drawable/test1"/>

    <TextView
        android:id="@+id/content1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World!"
        android:layout_marginTop="10dp"
        />

    <SeekBar
        android:id="@+id/sekkbar1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

    <TextView
        android:id="@+id/content2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/init_rotate"
        />
    <SeekBar
        android:id="@+id/sekkbar2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:max="360"/>
</LinearLayout>

第三逻辑代码如下

package com.example.myapplication1;

import androidx.appcompat.app.AppCompatActivity;

import android.graphics.Bitmap;
import android.graphics.Matrix;
import android.graphics.drawable.BitmapDrawable;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.SeekBar;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity implements SeekBar.OnSeekBarChangeListener {
      private final static int MIN_WIDTH = 200;
    private ImageView mImageView;
      private TextView mTextView1;
       private SeekBar mSeekBar1;
       private TextView mTextView2;
       private SeekBar mSeekBar2;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        findViewByid();
        setListners();
        setMaxValueForSeekBar1();
    }
    private void findViewByid(){
        mImageView = findViewById(R.id.img);
        mTextView1 = findViewById(R.id.content1);
        mTextView2 = findViewById(R.id.content2);
        mSeekBar1 = findViewById(R.id.sekkbar1);
        mSeekBar2 = findViewById(R.id.sekkbar2);
    }
    private void setListners(){
        mSeekBar1.setOnSeekBarChangeListener(this);
        mSeekBar2.setOnSeekBarChangeListener(this);
    }
   private void setMaxValueForSeekBar1(){
       DisplayMetrics dmDisplayMetrics = new DisplayMetrics();
       getWindowManager().getDefaultDisplay().getMetrics(dmDisplayMetrics);
       mSeekBar1.setMax(dmDisplayMetrics.widthPixels - MIN_WIDTH);
   }

    @Override
//    当滑块被拖动时会执行以下代码
    public void onProgressChanged(SeekBar seekBar, int i, boolean b) {
        if(seekBar.getId() == R.id.sekkbar1){
            int newWidth = i + MIN_WIDTH;
            int newHeight = (int)(newWidth*3/4);
            mImageView.setLayoutParams(new LinearLayout.LayoutParams(newWidth,newHeight));
            mTextView1.setText(getResources().getString(R.string.image_width) +
                    newWidth+getResources().getString(R.string.image_height)+newHeight );
        }else if(seekBar.getId() == R.id.sekkbar2){
            Bitmap bitmap = ((BitmapDrawable)getResources().getDrawable(R.drawable.test1)).getBitmap();
            Matrix matrix = new Matrix();
            matrix.setRotate(i);
            bitmap = Bitmap.createBitmap(bitmap,0,0,bitmap.getWidth(), bitmap.getHeight(),matrix,true);
            mImageView.setImageBitmap(bitmap);
            mTextView2.setText(getResources().getString(R.string.image_rotate)+i);

        }
    }

    @Override
    public void onStartTrackingTouch(SeekBar seekBar) {

    }

    @Override
    public void onStopTrackingTouch(SeekBar seekBar) {

    }
}

第四屏幕截图，文件结构截图