android - SeekBar 控制图片缩放

Question

这是seekbar的onProgressChangeListener

package com.example.android.seekbartest;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ImageView;
import android.widget.SeekBar;

public class MainActivity extends AppCompatActivity {

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

    iv = (ImageView) findViewById(R.id.imageView);
    sb = (SeekBar) findViewById(R.id.seekBar);
    sb.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
        @Override
        public void onProgressChanged(SeekBar seekBar, int progress, boolean b) {
            float scale =  ((progress / 10.0f)+1);
            iv.setScaleX(scale);
            iv.setScaleY(scale);
        }

        @Override
        public void onStartTrackingTouch(SeekBar seekBar) {

        }

        @Override
        public void onStopTrackingTouch(SeekBar seekBar) {

        }
    });
}
}

这是 Activity 的 XML

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.android.seekbartest.MainActivity">

<ImageView
    android:layout_height="wrap_content"
    android:layout_width="match_parent"
    android:id="@+id/imageView"
    android:src="@drawable/test"
    android:adjustViewBounds="true"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true" />

<SeekBar
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:max="15"
    android:layout_below="@id/imageView"
    android:layout_marginTop="20dp"
    android:id="@+id/seekBar"
    android:maxHeight="40dp"
    android:minHeight="40dp"
    android:thumbOffset="18dp"/>
</RelativeLayout>

这是输出

即使在缩放时，我也希望图像位于固定区域内。但它正在从中走出来。任何解决方案。或者还有其他更好的方法可以使用搜索栏在特定区域缩放图像吗？

Answer 1

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.android.seekbartest.MainActivity">

<LinearLayout
    android:layout_height="100dp"
    android:layout_width="match_parent">
<!-- Add the height and width over here, so that your image view doesnot exceed the LinearLayout frame -->
<ImageView
    android:layout_height="wrap_content"
    android:layout_width="match_parent"
    android:id="@+id/imageView"
    android:src="@drawable/test"
    android:adjustViewBounds="true"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true" /></LinearLayout>

<SeekBar
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:max="15"
    android:layout_below="@id/imageView"
    android:layout_marginTop="20dp"
    android:id="@+id/seekBar"
    android:maxHeight="40dp"
    android:minHeight="40dp"
    android:thumbOffset="18dp"/>
</RelativeLayout>