GestureDetector已弃用，Android Studio 2.3.3中相关方法失效求助

Hey there, let's break down why your onScroll method isn't working as expected after adding the v7:26.0.0-alpha1 dependency, and walk through actionable fixes.

The Root Causes #

1. Version Conflict Between Support Libraries
   You’re mixing a preview support library (v7:26.0.0-alpha1) with an older v4:25.3.1 library. Support libraries rely on consistent versioning across all components—mixing major versions can trigger hidden API behavior shifts, method resolution errors, or unexpected UI glitches that break your scroll logic.

2. Android Studio 2.3.3 Compatibility Limits
   Android Studio 2.3.3 is optimized for support libraries up to version 25.x. The 26.x support libraries require Gradle Plugin 3.0.0+ and newer Android Studio versions (3.0+), so your older IDE might not properly resolve or compile the newer library’s code.

3. Inconsistent Scroll Boundary Logic
   Looking at your onScroll code, the boundary check for maximum scroll position has a flaw that could cause jitter or failed scrolls, independent of library versions:

   if (sx + getWidth() > mTotalWidth) {
       sx -= distanceX;
   }
   

   This doesn’t reliably clamp the scroll position to the valid range (0 to mTotalWidth - getWidth()), leading to inconsistent behavior.

Step-by-Step Solutions #

1. Unify Support Library Versions (Quick Fix)

Stick to a stable, compatible support library version that works with Android Studio 2.3.3. Replace your dependencies with:

compile 'com.android.support:appcompat-v7:25.3.1'
compile 'com.android.support:support-v4:25.3.1'

This eliminates version conflicts and ensures all support library components work together seamlessly.

2. (Optional) Upgrade Tooling for 26.x Libraries

If you need to use v7:26.0.0-alpha1, you’ll need to update your development environment:

• Upgrade Android Studio to 3.0 or newer
• Update your project-level build.gradle to use a compatible Gradle Plugin:

  classpath 'com.android.tools.build:gradle:3.0.1'
  

• Update your Gradle wrapper in gradle/wrapper/gradle-wrapper.properties:

  distributionUrl=https\://services.gradle.org/distributions/gradle-4.1-all.zip
  

3. Fix the Scroll Boundary Logic

Replace your scroll clamping code with a robust implementation to ensure consistent scrolling:

@Override
public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
    mScrolled = true;
    int sx = getScrollX();
    sx += distanceX;
    // Clamp scroll position to valid range: 0 <= sx <= (mTotalWidth - getWidth())
    int maxScrollX = mTotalWidth - getWidth();
    sx = Math.max(0, Math.min(sx, maxScrollX));
    mTargetScrollX = sx;
    scrollTo(sx, getScrollY());
    invalidate();
    return true;
}

This guarantees the scroll position never goes beyond valid boundaries, preventing unexpected behavior.

Final Checks #

After making these changes, clean and rebuild your project (Build > Clean Project then Build > Rebuild Project) to clear cached build artifacts that might be causing lingering issues.

内容的提问来源于stack exchange，提问作者Youn Tivoli